DE102016013115A1 - Manufacturing method for an air duct of an aircraft - Google Patents

Abstract

In a method for producing an air guide tube (18) for an air guidance system in an aircraft, a preform (2) is provided with an inner space (6) at least tube-like surrounded by a wall (4), this in a production means (14) according to the outer contour the inside of the air duct (18) formed inner wall (16) introduced, or arranged around a manufacturing means (14) according to the inner contour of the air duct tube (18) formed outer wall, the interior (6) of the preform with positive pressure (pü) and / or a gap ( 20) between the wall (4) of the preform (2) and the inner wall (16) of the manufacturing means (14) with negative pressure (pu) acted upon or the outside space of the preform with overpressure (pü) and / or a gap (20) between the Wall (4) of the preform (2) and the outer wall of the manufacturing means (14) with negative pressure (pu) is applied, wherein the preform (2) to the inner wall (16) or outer wall rests u formed to the air guide tube (18), and the air guide tube (18) removed from the manufacturing means (14).

Description

The invention relates to a method for producing an air duct for an air duct system in an aircraft.

Air duct systems in aircraft construction or ventilation ducts for an air duct system in an aircraft are commercially available in a variety of ways. Such air ducts are usually made in low-pressure hose technology, which with a high number of individual strips and thin layers of fiber-reinforced plastic, the variety of forms of air ducting systems in handmade unique copies. The layers are manually inserted into a mold and pressed by means of a low-pressure hose to the outside against the inner wall of the mold.

The object of the present invention is to improve the production of such an air guide tube.

The object is achieved by a method according to claim 1. Preferred or advantageous embodiments of the invention and other categories of invention will become apparent from the other claims, the following description and the accompanying drawings.

The method is used to produce an air guide tube, wherein the air guide tube is set up as an air guide tube for an air guide system in an aircraft. The aircraft is in particular a military or civil aircraft, helicopters or the like. According to the method, a preform for the desired air duct is provided. The preform in this case has an inner space which is enclosed by a wall at least tubular. "Pipe-like" here means that it is a tubular, extending along a line extending body whose longitudinal side walls, that is, the walls in the circumferential direction, are completely closed. Only the longitudinal tube ends are open if necessary. The interior is thus at most not completely enclosed by the wall at one or both pipe ends.

The preform is introduced into a production tool. The inner wall of the manufacturing means is shaped according to a desired outer contour of the air guide tube. The interior of the preform is then pressurized. Alternatively or additionally, a gap between the wall of the preform and the inner wall of the manufacturing means is subjected to negative pressure. By or at least with the cooperation of the pressurization, so acting under pressure and / or overpressure, the preform sets - usually expansive - to the inner wall of the manufacturing means and is thereby formed into the air duct. The expansion and the application is done "at least" by the pressure, optionally by interaction with other, later mentioned measures.

After the preform has adopted the desired shape of the air guide tube, or the preform has been converted into the guide tube, the air guide tube is removed from the manufacturing means.

The previous description referred to a preform which was introduced into a production means. However, the manufacturing means may alternatively be introduced into the preform. In other words, the preform is arranged around the production means. All conditions then turn around only, so apply mutatis mutandis, as stated above. For example, Then, the inner contour of the preform is formed according to the outer wall of the manufacturing means. The outer space of the preform is subjected to overpressure and subjected to the gap between the preform and the outer wall of the manufacturing means with negative pressure. The preform then rests with its inner wall against the outer wall of the manufacturing means and is thereby formed with the desired inner contour of the ventilation tube.

In the following, only the case will be explained, without restricting the generality, that the preform is introduced into the interior of a production tool. However, the statements also apply mutatis mutandis to the fact that the manufacturing means is introduced into the preform ("reverse variant"). Respective ratios (inner wall / outer wall, interior / exterior space) are then considered mutatis mutandis, if appropriate, in reverse.

The method can be carried out at least largely mechanized, that is, it is especially against the low-pressure hose technology hardly manual steps necessary, which is why the working time for the production of an air duct tube drops and thus the air duct can be produced more cheaply. Essentially, the manufacturing process comprises only a single step, namely the expansion of the preform into the shape of the air guide tube or pipes. The method can also be carried out quickly and inexpensively to this effect. In particular cost-effective and functional, ie "simple", air ducts can be produced with the aid of the method: these fulfill their core task, namely the air duct, in the desired quality, eg with regard to pressure tightness of the wall, little friction for air to be carried out and sufficient deformation resistance of the wall Air guide tube. Other properties - eg thermal insulation and / or acoustic flow behavior - are less pronounced.

According to the invention, particularities of the process or method relating to aviation can be particularly well taken into account, e.g. self-rigidity in the process by ribbing, the introduction of shape-function contours or impressions for labels and aerospace marks, the setting of compressive strength, airtightness, and certain flow resistance (friction), making connections, branches, reinforcements or material connections, etc.

In a preferred embodiment, a pressure transmission means, in particular a hose or inner tube, is introduced into the preform. The pressure transmission means is then pressurized from the inside and pushes with its outer surface against the inside of the preform. Thus, a pressure medium in the interior of the pressure-transmitting means does not come into contact with the preform and can be chosen as desired, without having to pay attention to material pairing with the preform. In addition, the pressure transfer means can be made particularly pressure tight to allow large pressing forces on the preform when e.g. the preform itself is not sufficiently pressure tight.

In the reverse variant, the preform is wrapped by a corresponding tube. The wrapping can also be in the form of a vacuum packaging. As a result, pressure is exerted on the preform from the outside in order to press this or its inside towards the outside of the production means.

In a preferred embodiment, the preform is additionally subjected to heat during the application of overpressure and / or underpressure in the production means (or outside the production means, inverted variant), that is to say a supply of heat is effected. The expansion and the application of the preform to the inner wall of the manufacturing means thus done by the interaction of pressure and heat, which brings an improved application with it. In addition, by heating depending on the material of the preform and curing of the preform or air duct tube in the manufacturing means can be achieved after this has assumed its desired shape.

The heating takes place in particular via a flow through the preform with a heated medium, in particular gas (in particular air) or liquid. The flow takes place in particular alongside the entire preform. In particular, pressure medium thus enters at one end of the preform and leaves it at the other end.

A "heat input" here also means a defined temperature which is maintained during the production process by defined heat supply / removal. A suitable temperature, which is not too cold and not too warm, can be found here. Preference is given to an optimum in terms of material (flow behavior, mechanical but also chemical properties - eg degassing, embrittlement, etc., surfaces - eg wetting behavior, etc.) and process, machine characteristics (also heating medium, pressure, flow, temperature, Location, etc.) and desired processing (eg process time, cost optimization, etc.). This is especially true for a flow with medium, but mutatis mutandis, for all other process variants.

In a preferred variant of this embodiment, the air guide tube is cooled before removal from the production means (removal of the production means from the preform, reverse variant). As a result, easier handling of the cooled air duct tube is achieved during removal and depending on the material of the air duct tube curing of the air duct tube before removal improved.

The cooling is also carried out in particular by means of the flow through a cooling medium, in particular cool gas or cool liquid. "Cooling" means that heat removal from the air duct tube is possible, i. in particular, the temperature corresponds at most to the target temperature of the ventilation pipe.

In a preferred embodiment of the method, the air guide tube is finished after removal from the production means. Here, for example, openings are introduced into the air duct, attaching additional parts to this or the air duct tube end trimmed to a desired shape of the ends or a desired length. Such post-processing or final production steps are usually fast and inexpensive feasible.

In a variant of this embodiment, the air duct is finished so that it is trimmed at least at one of its pipe ends. Thus, by a simple post-processing step, a clean pipe end, e.g. be produced with the desired oblique section, without having to take into account when shaping in the manufacturing means. Also, manufacturing ends, e.g. a pressure connection flange, to be removed.

In a preferred embodiment, a cylindrical, in particular circular cylindrical, in particular over the tube length constant diameter, preform is provided. Such preforms are particularly simple and inexpensive to produce and can be shaped depending on the shape of the manufacturing means flexible in various air ducts.

In a preferred embodiment, a preform is provided which is open at one end of the tube and closed at the other end of the tube. Due to the open end of the pipe, a simple pressure feed into the interior is possible. Due to the closed end of the pipe, no separate sealing of the preform during pressurization must be carried out at this end of the pipe.

In an alternative embodiment, a preform is provided which is open at both ends of the pipe. In this way, on the one hand take place at both ends of the pipe pressure introduction, also such preforms are usually even easier and cheaper to produce than those with a closed end.

In a preferred embodiment, a preform is provided which is an extrudate and / or rod product. Such preforms can be procured in a particularly simple and cost-effective manner, which ultimately affects the cost of the air guide tube.

In a preferred embodiment of the method, at least one or both of the open tube ends of the preform is closed prior to pressurization by compression between parts of the production means. In particular, the production means has two (also unequal) parts or halves, which can be moved apart for insertion of the preform. The parts for pressing the ends of the preform are in particular the two halves of the production means. A separate sealing of the pipe end by an additional step or an additional part is therefore not necessary, the closure is done in particular automatically when closing the manufacturing means, e.g. when matching the halves. In particular, the production means is thus carried out in two or more parts, is opened for inserting the preform and for removing the air guide tube and closed during pressurization. The pressing is then done simply by closing the tool after inserting the preform.

In a preferred embodiment, an open (tube) end of the preform is closed with a closure means prior to its pressurization. Thus, no special requirements are to be placed on the manufacturing means in this regard. A closure means is in particular a stopper or a cap. The closing occurs in particular before, during or after the insertion of the preform in the manufacturing means.

In particular, the closure means includes a passage for a pressure medium. So pressure medium can be particularly easily introduced into the preform. In particular, the preform is pressed between the closure means and the production means.

In a preferred embodiment, an overpressure in the interior (overpressure in the outer space or negative pressure in the interior or between preform and production means, reverse variant) of the preform is produced by the fact that the wall of the preform is penetrated by a pressure feed means. The enforcement is pressure tight, i. tight enough to build up the required overpressure in the preform. Such a procedure is carried out in particular by means of a dome, which penetrates the wall or can pierce. The pressure supply means is thus designed as a mandrel. In particular, the mandrel has a tip, so that with this the wall is pierced in order to introduce the pressure supply means. Thus, the preform no special precautions for other pressure introduction, such as connecting flanges or threads or nozzles are provided. Thus, particularly simple preforms can be used.

In a preferred embodiment, an overpressure in the interior of the preform (negative pressure in the interior or between preform and manufacturing means, reverse variant) is generated in that the overpressure -. in the form of a pressurized medium, gaseous (e.g., air) or liquid - via one or, if present, both of the open tube ends of the preform are introduced. Thus, an already open pipe end can be used for pressure introduction and is sealed pressure-tight by connecting to a pressure supply. Further measures for the introduction of pressure need not be carried out on the preform. In particular, the tube end can already be formed as a connection means for a pressure feed, for example as a flange, thread or socket on the preform. The connection of a pressure feed is then particularly easy.

In particular, the preform is flowed through by the pressure medium, in particular thus the medium is introduced at one of the two pipe ends and discharged at the other end of the pipe. The medium is under pressure.

In a preferred embodiment, the preform is provided by being selected from an assortment of preforms. Thus, different preforms for different classes of air guide tubes can be kept and the appropriate one for the production of the respective air duct tube are selected. Classes of air ducts are for example those of the same length but of different shape, for which a preform of a certain length is kept. Air ducts of a different length are then made from another preform.

In a preferred variant of this embodiment, the preform is selected from an assortment whose preforms differ in terms of their length and / or cross section and / or wall thickness. Thus, particularly simple assortments of preforms are defensible. The distinction in cross section is in particular a distinction purely in the diameter, in particular, when all preforms are cylindrical.

The invention is based on the following findings or considerations, wherein in this context as "invention" also embodiments of the invention are mentioned, which correspond to combinations of the above embodiments and / or optionally also include previously not mentioned embodiments.

The invention is based on the idea of using an alternative technology for producing air duct systems in aircraft construction. The innovation here is a technological concept, which uses an optimal balance of mass produced and prefabricated preforms and also allows a high geometric detailing and variety of shapes. For example, an assortment of only ten standard preforms is needed to make a wide variety of air ducts.

According to the invention, the preforms are placed under pressure and heat. The preform takes after a short time the shape and detail of the surrounding production means. After cooling, the finished molded component is produced as a raw or delivery stage. According to the invention there is a cost advantage, a time saving in production. In addition, the highest quantities are possible and in particular to 100 percent exact mass production. The result is a fault elimination of false allocations, as in the low-pressure hose technology possible, namely, for example, if used false prepreg strips or inserted in a wrong place in a mold.

According to the invention there is a completely new method for the production of air ducts for air duct systems in aircraft. The invention describes a technology for the production of thin-walled air guidance systems. In accordance with the invention, manual insertion of strips in low pressure hose technology is replaced by rapid, shape defining fabrication by heating / vacuum / positive pressurization.

According to the invention, prefabricated, standardized preforms with different diameters and wall thicknesses are procured in large quantities depending on the geometry and static requirements of the finished component, each clamped individually in a mold and placed under negative pressure (ambient) and / or pressure (inside). When the preform warms, it becomes malleable. Due to the applied pressure this is pressed to the shape of the production means and assumes its shape and detail. After cooling, the former preform is transformed into a plastically firmly formed component, which can be used or further processed, for example by gluing on holders. The invention finds application in principle in all air duct systems of manufacturers in the field of aviation, which are designed as a pipeline.

At least partial aspects of the invention can be summarized as follows:

• - Durchströmung bei zweiseitig offenen Vorformlingen (z.B. Gase oder Flüssigkeiten),
• - Erwärmung über einseitige Anschlüsse durch:
  • - Lanzen bei einseitig offenen Vorformlingen (Strömungstransport im Bauteil von Gasen oder Flüssigkeiten; Vorteile durch Zentralanlagentechnik und Strömungsdosierbarkeit) oder
  • - Düsen bei einseitig offenen Vorformlingen (Impulseinströmung von Gasen oder Flüssigkeiten; Vorteile durch Zentralanlagen und bei geometrisch schwierigen Bauteilen) oder
  • - Stäben bei einseitig und zweiseitig offenen Vorformlingen (z.B. elektrische Erwärmung eines Heizstabes im Inneren des Bauteiles / Fertigungsmittels; Vorteile in geringer Anlagentechnik und Energiedosierbarkeit).
  Für die Varianten mit Lanzen oder Düsen ist insbesondere jeweils ein Abströmanschluss vorgesehen.
• - Vorwärmung des Vorformlinges als Prozess bei geometrisch schwierigen Bauteilen.

According to the invention, various forms of preforms can be used (open on one side, open on two sides). In the process various forms of heating of the preforms / air ducts are possible. Thus, manufacturing processes exist by means of preforms with externally heated processes (eg via production means or in advance directly on the material) and internally heated processes. Here are to call

• - flow through two-sided open preforms (eg gases or liquids),
• - Heating via one-sided connections through:
  • - Lances for unilaterally open preforms (flow transport in the component of gases or liquids, advantages of central plant technology and flow dosing) or
  • - Nozzles with preforms open on one side (pulse inflow of gases or liquids, advantages of central systems and geometrically difficult components) or
  • - Rods with unilaterally and bilaterally open preforms (eg electrical heating of a heating element inside the component / production tool, advantages in low system technology and energy dissipation).
  For the variants with lances or nozzles in particular in each case a Abströmanschluss is provided.
• - Preheating of the preform as a process for geometrically difficult components.

On the basis of the specific use in aircraft as well as on the basis of economic economics and constructive geometry, specifically newly developed heat processes, supplementary special processes and connection methods are described, which particularly benefit the use of the productive results under high and highest loads. Thus, the methods described in the context of the invention aim at economic advantages in the productive implementation of the high-quality end product in a variety of forms with industry-specific low quantities.

In order to implement the technologically-constructively high-quality requirement for the end product, the constructive conversion methods described in the context of the invention were developed and described below under the heading "Optional design specifics". The plant technology described below under the heading "Heating Processes" is specially designed in accordance with the above-mentioned principles. The underpressure and / or overpressure described below under "Supplementary Special Processes" and "Tying Processes" is directly related to this.

For the "preform" the following is to be done:

First of all, according to the use (continuous pipes or special case closed pipe forms) in the specific manufacturing technology "tube production by preforms" it is decided whether preforms open on both sides or preforms that are open on one side are used. Here, the use in the context of the invention of preforms open on both sides has advantages in the production of typical end products with double-sided opening (pipes), while unilaterally open preforms enable it technologically to produce so-called "pipe sacks" (for example separator pipes).

The best-known manufacturing methods for open-sided preforms are cost-effective endless production in extrudate or an injection-molded preform. Unilateral open preforms are usually produced by injection molding. The production process extrudate or injection molding of the preform itself are prior art and not part of the patent application; the specific uses of the preforms as described are part of the invention.

For "optional design specifics" the following is to be done:

In order to meet load-related requirements (for example pressure, thermal behavior, strength, insulation, safety margins, flight relevance) in the constructive implementation of "preform pipe production", various design specifics are available for optional application in addition to the use of a straight or preformed pre-formed preform.

Here, material hybrids, specific shape geometries, reinforcements and material doublings or structured surfaces are used.

Material hybrids have due to the combination of two or more materials, fully or teilflächige applied, while, upstream or downstream of the process of "tube production by preforms" special technological properties as a result of the tube. Thus, a) similar materials or b) different types of materials can be used. Under a) is described the combination of materials belonging to the same category of material (e.g., plastics, metals, glasses) and which are joined together in the process of "preforming tubes". Thus, in the example of a same material category, plastics' advantages result in material stiffnesses in the hybrid application of thermoplastic materials in conjunction with thermoset materials. Under b) the connection of materials is described in which materials of different material categories are used and which are connected to each other in the process of "preform tube production". Thus, in the example of a different material combination of 'plastic with, metal' advantages in the thermal resistance arise when thermoplastic materials are connected to metals, for example in sheet form.

Due to the specific shaping of the geometry of the final product, mold geometries have advantages both in terms of positively influencing the static and dynamic properties of the component and in terms of use-related shape geometries (for example anti-slip devices, clamp stops, direction changes, cross-sectional changes, molded-in diaphragms). In this case, geometric shapes are to be chosen which favor the processes described under "Specific shaping" below for "tube production by means of preforms"; for example, "flowing" transitions, avoiding the formation of sharp edges, specific demolding geometries.

Attachments and components are parts connected to the pipe a) both in the process of "preform pipe making" and b) parts connected after the process of "preform pipe making". The attachments and components mentioned under a) are applied by means of insertion or fixation within the specific shaping process of "tube production by means of preforms". By way of example, the insertion of two preforms into the shaping process of "tube production by means of preforms" for the purpose of connection to a tube is named as end product. Furthermore, by way of example, the insert of a separate identification plate in the production means and thus in the molding process of the "pipe production by means of preforms" for the purpose of connection of the identification plate with the end product called pipe. The attachments and components mentioned under b) are applied by means of gluing, welding or other bonding methods before or after the specific shaping process of "preform pipe production". By way of example, the sticking of pipes to create branches or the sticking of holders for pipe fastening may be mentioned later in the shaping process of "pipe production by means of preforms". Another example is the sticking of a pipe sleeve before the forming process of the "tube production by means of preforms" mentioned, which is enclosed in the molding process of the preform and thus glued in the final product and additionally fixed by molding.

Structured surfaces are superficially introduced in the shaping process of the "tube production by means of preforms" introduced structures, depending on the design material structure or only superficially on the inside or outside of the final product. In addition, the strength of the component favoring material residual stresses can be created in the material structure of the final product, if it is desired that these structures not only have a purely superficial effect. A distinction is made between a) textured user surfaces and b) structured design surfaces. In a), "preform tube production" means surfaces which have a direct product benefit in the final product. By way of example, labeling surfaces may be named here, for example, for parts identifiers or aviation approval numbers, which are imaged directly during the forming of the preform by the production means in the end product in the shaping process of "pipe production by means of preforms". Furthermore, structural surfaces may also be named by way of example which, by utilizing the flowability of the preform, image structured surfaces, for example for the local absorption of hand loads on the end product. Furthermore, by way of example, acoustically effective or pressure-loss-influencing surfaces are also named for media flow through the end product tube. Under b) all non-user surfaces are understood. These include, by way of example, design surfaces which fulfill an aesthetic purpose in visible areas.

For "specific shaping" the following is to be done:

In the forming process of "pipe production by means of preforms", a distinction is made between different heating processes, special processes and bonding processes, depending on the existing plant technology.

In "Heat Processes, Indoor Warming" (see below), heat sources are directed to the interior of the preform to achieve preform deformation using "bonding, underpressure and / or overpressure" (see below).

For "heating processes, internally heated", the following must be stated:

The "rod" variant has heating by means of an inserted heating rod, for example electrically operated, which heats the preform from the inside and leads to a geometrical tube under the specified special processes and processes for "tube production by means of preforms". A particular advantage in this case is the applicability on both sides or unilaterally open preforms and a uniform over the heating rod, easily controllable heat distribution. However, restrictions could arise with the well-positioned rigid heating rods by the desired geometry of the end product. For this purpose, the variant "rod" offers a useful alternative when using a flexible heating conductor.

The variant "nozzle" obtains as an alternative to "rod" by means of a nozzle-like injected introduction of a liquid or gaseous heating medium, the heating of the Preform which internally heats the preform and results in a geometrical tube under the specified special processes and processes for "preform tube fabrication", also using flow pulses for induction effects in the die injection. A particular advantage in this case is the applicability to both sides or unilaterally open preforms, with complex geometry of the final product and a well-regulated amount of heat. However, a comparatively complex system technology is necessary.

The variant "lance" obtains alternatively "rod" by means of lance-guided introduction of a liquid or gaseous heating medium, the heating of the preform, which heats the preform from the inside and leads to a geometric tube under the specified special processes and processes for "tube production by means of preforms". A particular advantage in this case is the applicability to both sides or unilaterally open preforms, with complex geometry of the final product which selectively stronger heating need and a well-regulated amount of heat. However, a comparatively complex system technology is necessary.

The variant "throughflow" obtains as an alternative to "rod" by flowing a liquid or gaseous heating medium, the heating of the preform, which heats the preform from the inside and leads to a geometric tube under the specified special processes and processes for "tube production by means of preforms". A particular advantage here is the applicability of highly complex geometry of the final product and a relatively quickly introduced, easily controllable amount of heat. However, it is a relatively complex system technology necessary and applicable only for both sides open preforms.

In "heating processes, outdoor heated", heat is introduced to the tooling or preform prior to molding to achieve deformation of the preform using "underpressure and / or overpressure". Outdoor heated heating processes can be combined with internally heated heating processes and vice versa for the purpose of process and cost optimization.

The variant "built into the manufacturing means" has an existing in the forming tooling heat source, which heats the preform from the outside and leads to a geometric tube under the specified special processes and processes for "tube production by means of preforms". In this case, both electrical (for example heat wires, heating rods) and heating medium-controlled heat sources can be used. A particular advantage lies in the compact system technology and the good metering of the heat input

The variant "via the tooling surface" has a heat applied to the molding tool, which first heats the tooling and then the preform from the outside and leads to a geometrical pipe under the specified special processes and processes for "preform pipe production". In this case, almost all known heat sources, electromagnetic waves and ovens can be used. The particular advantage of this heating process is the economy of mass heating and the comparatively easy handling of the process.

The variant "heating preform outside of the production means" and subsequent shaping with the aid of "bonding method, underpressure and / or overpressure" is of particular economic benefit as a process because of the very low plant expenditures.

For "supplementary special processes", the following must be stated:

"Outer / Inner Shaping Shapes" has been developed to reflect specific surface finish requirements. In this case, the surface of the preform facing the production means is imaged in a special surface quality, wherein the side facing away from the production means has a somewhat lower surface quality as a result of the process. Thus, this supplementary special process is one of the necessary selection criteria under the heading "Optional Design Specifics" as well as under the heading "Specific Design". All processes described under "Optional Design Specificives" as well as under "Specific Forming" for external and internal forming production equipment are used analogously.

"Hoses or vacuum packaging" can be placed in the component or coated and applied depending on the nature of the process for specific shaping already before heat input and / or during the heat input and during the cooling phase with pressure. This pressure can be carried out both as overpressure and / or as negative pressure. In addition, different pressure levels can be applied over the entire process cycle, so that the specific shaping can follow the individual process phases optimally adapted. The aspect of the invention described in the section "Outer / Inner Forming Shapes" serves to apply shaping forces uniformly to the preform to be formed both from the outside and from the inside, and also to thermally balance different thermal loading by the heat source and protect the preform from excessive radiant heat ,

"Preheating" represents a special process in such a way that, depending on the material characteristics of the preform, a specific temperature level of the overall process must be ensured in order to ensure both the process training and, if necessary, to minimize residual stresses or fault formation. In addition, an adjustment of the materials described under "material hybrids" in heat capacities is to be made possible thereby. A Shortening the process times and preventing "shrinking" before and after the shaping process on production means are in addition to a more fluid shaping further significant advantages of preheating and / or reheating (eg, heat retention phase). The "preheating" aspect has to be distinguished from the option "heating preform" in that it concerns the temperature level adjustment of the process and not the creation of the forming temperature per se.

"Clamping devices" or "holding devices" are all devices that support the process named under "Specific shaping" in addition to the manufacturing equipment. These include, for example contour-adapted holding, clamping and / or trimming devices, clips and clamps for fixing preform and / or attachments, components or material hybrids and the like.

For "connection, underpressure and / or overpressure" the following must be stated:

Preforms open on both sides and preforms open on one side can each be connected in different ways (pressing between parts of the production tool, closure means, mandrel, etc.). The connection is made specifically depending on the processes described for preform and design specifics as well as the heating processes and special processes. Basically, an underpressure and overpressure connection takes place in the following manner, whereby both processes with only negative pressure and only overpressure are possible. In processes with only under or overpressure, the atmospheric pressure prevailing in the process can be used.

1. A) „Anbindungsverfahren über Deckel oder Druckplatte“ ist eine Anschlussart, welche die ökonomische, da standardisierbare Anschlussmöglichkeit sowohl der Wärmeprozesse als auch optional der Druckprozesse einschließlich optional der ergänzenden Spezialprozesse ermöglicht.
2. B) „Geklemmte Anbindungsverfahren“ sind solche, in denen sowohl der Vorformling, das Fertigungsmittel als auch Wärme- und/oder Druckanbindungen sowie die Ergänzenden Spezialprozesse zur Anbindung geklemmt werden. Hierbei können dichtende Einlagen, Stutzen oder materialoberflächig dichtende Anbindungen verwendet werden. Geklemmte Anbindungsverfahren stellen aufgrund der flexiblen Anwendung einen wirtschaftlichen Vorteil bei der produktiven Umsetzung in vielfältigen Formen mit branchenspezifisch geringen Stückzahlen dar.
3. C) „Anbindungsverfahren mittels gequetschter Verbindung“ ist insbesondere für einen kurzen Prozesszyklus von Vorteil, da kaum weiterer manueller Aufwand für den dichten Verschluss des Vorformlinges während des Prozesse notwendig wird und stellt somit eine ökonomische Alternative in Abwägung zu dem prozesstypisch etwas höheren Verschnitt am Vorformling im Vergleich zu den anderen benannten Anbindungsverfahren dar.
4. D) „Anbindungsverfahren Endlos“ sind darauf ausgerichtet entwickelt worden, um bei möglichst geringem Verschnitt - welcher ökonomischen Verlust darstellt - eine möglichst geringe Prozessdurchlaufzeit produktionstechnisch umzusetzen. Hierbei ist das Anbindungsverfahren von Wärmeprozessen als auch Druckhaltungsprozessen dergestalt, dass die Wärmeprozesse lokal einbringend gestaltet werden und die Druckhaltungsprozesse unter optionaler Anwendung von Kombinationen mit anderen hier benannten Anbindungsverfahren umgesetzt wird. So ist zum Beispiel eine Druckanbindung über das oder die freien Enden des Vorformlinges optional mit der bereits beschriebenen geklemmten Anbindung und optionalem Unterdruckanschluss über das Fertigungsmittels möglich, während die Wärmeanbindung optional über „Wärmeprozess, außenerwärmt“ (z.B. gemäß der Variante „Eingebaut in Fertigungsmittel“) erfolgt. Weitere Kombinationen gemäß der im Patentanspruch beschriebenen Prozesse können gewählt werden.
5. E) Anbindungsverfahren über geschraubte, bajonettierte oder sonstige standardisierte Verbindungen von Vorformling, dem Fertigungsmittel als auch Wärme- und/oder Druckanbindungen sowie die ergänzenden Spezialprozesse stellen aufgrund der gegebenenfalls benötigten hohen Prozessparameter Druck und/oder Temperatur eine erhöhte Sicherheit in den Verbindungsbereichen im Prozess dar.

The connection methods described in the invention serve the optimized economic and technical implementation.

1. A) "Connection method via cover or printing plate" is a connection type which allows the economic, as standardizable connection possibility of both the heating processes and optionally the printing processes including optionally the supplementary special processes.
2. B) "Boundary connection methods" are those in which both the preform, the production means as well as heat and / or pressure connections as well as the supplementary special processes for connection are clamped. Here, sealing inserts, nozzles or material-surface sealing connections can be used. Due to the flexible application, tethered connection methods represent an economic advantage in the productive implementation in various forms with industry-specific small quantities.
3. C) "Connection method by means of crimped connection" is particularly advantageous for a short process cycle, since hardly any further manual effort is required for the sealing of the preform during the process and thus represents an economical alternative in comparison to the process-typical slightly higher proportion of the preform in the Compared to the other named connection methods.
4. D) "Tying Endless" have been developed in order to implement the smallest possible waste - which represents economic loss - the lowest possible process cycle time production technology. In this case, the bonding method of heat processes as well as pressure maintenance processes is such that the heat processes are designed locally introducing and the pressure maintenance processes is implemented with the optional application of combinations with other attachment methods mentioned here. Thus, for example, a pressure connection via the or the free ends of the preform is optionally possible with the already described clamped connection and optional vacuum connection via the manufacturing means, while the heat connection optional "heat process, externally heated" (eg according to the variant "built-in manufacturing means") he follows. Other combinations according to the processes described in the claim can be selected.
5. E) Connection methods via screwed, bayoneted or other standardized connections of preform, the production means as well as heat and / or pressure connections and the supplementary special processes represent increased safety in the connection areas in the process due to the possibly required high process parameters pressure and / or temperature.

All variants and alternatives mentioned in the context of the invention can be used together as long as they do not contradict each other.

• 1 einen Vorformling mit einen geschlossenen Ende,
• 2 den Vorformling aus 1, eingelegt in ein Fertigungsmittel,
• 3 den im Fertigungsmittel zum Luftführungsrohr umgeformten Vorformling,
• 4 das entnommene Luftführungsrohr und seine Nachbearbeitung,
• 5 einen alternativen Vorformling mit zwei offenen Enden,
• 6 ein alternatives Fertigungsmittel für den Vorformling aus 5,
• 7 das Fertigungsmittel aus 6 mit eingelegtem Vorformling,
• 8 den im Fertigungsmittel zum Luftführungsrohr umgeformten Vorformling,
• 9 das entnommene Luftführungsrohr und seine Nachbearbeitung,
• 10 einen Vorformling in einem alternativen Fertigungsmittel mit Schlauch,
• 11 das gefertigte Luftführungsrohr gemäß 10,
• 12 ein alternatives Fertigungsmittel zur Mediendurchströmung,
• 13 Vorformling und Luftführungsrohr im Fertigungsmittel gemäß 12.

Further features, effects and advantages of the invention will become apparent from the following description of a preferred embodiment of the invention and the accompanying figures. This shows in a schematic outline sketch:

• 1 a preform with a closed end,
• 2 the preform 1 , inserted in a production tool,
• 3 the preform formed in the production means into the air guide tube,
• 4 the removed air duct and its post-processing,
• 5 an alternative preform with two open ends,
• 6 an alternative manufacturing means for the preform 5 .
• 7 the manufacturing equipment 6 with inlaid preform,
• 8th the preform formed in the production means into the air guide tube,
• 9 the removed air duct and its post-processing,
• 10 a preform in an alternative manufacturing means with hose,
• 11 the manufactured air duct according to 10 .
• 12 an alternative means of production for media flow,
• 13 Preform and air duct in the production means according to 12 ,

1 shows a preform 2 in the form of a preform with a wall 4 that have an interior 6 of the preform 2 both tubular, that is, here at the cylindrical peripheral wall, as well as at its first pipe end 8a encloses. At the pipe end 8b is the preform 2 open and has a connection means 10 for a in 1 not shown pressure feed means 12 , for example a pressure hose. The connection means 10 here is a screw thread. Alternatively, the connection means 10 an unillustrated nozzle, which in a pressure supply means 12 is clamped. The preform 2 is provided for the method described below. In an alternative embodiment (not shown) is also at the pipe end 8b - or alternatively at other locations of the preform 2 - a connection means 10 intended.

According to 2 becomes the preform which is further simplified here 2 in a production tool 14 clamped. An interior wall 16 of the production means 14 is according to a desired outer contour of an air duct to be manufactured 18 shaped (in 2 not yet shown). This in 2 only indicated connection means 10 is with the pressure supply means 12 connected to overpressure pu in the interior 6 of the preform 2 to create. In addition, in a gap 20 between the wall 4 of the preform 2 and the inner wall 16 or the production means 14 a negative pressure pu generated. The pressures are in 2 only symbolically represented as arrows. The production tool 14 or its design takes into account an expansion and / or shrinkage and / or elasticity of the preform 10 , In case of several connection means 10 (how to 1 also explained) with the or an alternative pressure feed means 12 connected.

According to 3 becomes the preform 2 also with heat W applied. The preform 2 expands due to the applied pressures pu , pu and the heat W out, so that its wall 4 with its outer surface to the inner wall 16 applies, why the preform - at least with respect to its outer contour - the desired shape of the ventilation pipe 18 accepts or to the ventilation pipe 18 is transformed. After completion of the deformation and, where appropriate, a cooling of the ventilation pipe 18 this is out of the production tool 14 taken.

4 shows the removed air duct 18 as well as additional processing steps, after removal from the tooling 14 be carried out, namely by arrows 22a . b indicated bleed the air duct 18 , By trimming the pipe ends become 8a . b of the air duct 18 designed as desired or is the ventilation pipe 18 finally to a desired length I shortened. In addition, it will be at the end of the pipe 8a the closed and no longer required pipe end separated, and at the pipe end 8b also no longer required connection means 10 separated.

5 shows an alternative preform 2 in the form of an extrudate or a rod product. This one points like the one in 1 shown preform 2 again a tubular closed wall 4 on, but which deviates also at the pipe end 8a and thus on both pipe ends 8a . b is open. The preform 2 So here is a cylindrical tube.

6 shows an alternative means of production 14 to which a connection means 24 for negative pressure pu , here's one to the inner wall 16 leading bore, is provided. The production tool 14 Also includes an alternative pressure feed means 12 which is here as a thorn 26 is executed. The thorn 26 reaches into the interior of the production tool 14 , or stands out of the inner wall 16 in front. Alternatively, the thorn 26 be arranged or used in another direction, for example obliquely, parallel or perpendicular to a longitudinal axis of the arrangement. The production tool 14 is made in two parts, with longitudinal direction of the preform to be inserted 2 each end pressing means 28 are present, which are when joining both parts of the manufacturing means 14 transverse to the direction of extension of the inserted preform 2 each press each other. Here, too, the manufacturing equipment pays attention 14 or its configuration again an elongation and / or shrinkage and / or elasticity of the preform 10 ,

7 shows the manufacturing equipment 14 with inlaid preform 2 in which the two parts 30a . b lie against each other, the manufacturing means is therefore closed. The preform 2 is in the area at or near its pipe ends 8a . b each between the pressing means 28 pressed so that the preform with respect to its interior 6 completely sealed. However, access to the interior 8 is through the mandrel 26 created the wall 4 has punctured and now interspersed sealing. Thus it is thanks to the pressure feed means 12 allows overpressure pu in the interior 6 build. In other words, therefore, a pressing of the pipe ends 8a . b between the parts 30a . b of the production means 14 and a mandrel or needle injection through the wall 4 for supplying the overpressure PÜ. Now the negative pressure pu and the overpressure pu created. The negative pressure pu acts again in the space 20 between preform 2 and manufacturing equipment 14 or its inner wall 16 ,

8th again shows the additional contribution of heat W on the preform 2 again by the action of heat W , Overpressure pu and negative pressure pu the shape of the ventilation pipe 18 has assumed, or to the air duct 18 was reshaped. warmth W as well as overpressure pu and negative pressure pu are generated at least temporarily at the same time. After cooling the ventilation pipe 18 this will be removed from the tooling 14 taken.

9 shows the removed ventilation pipe 18 in which again at the pipe ends 8a . b , indicated by the arrows 22a . b , a trimming is performed. This is how the ventilation pipe is made 18 to the desired length I cut to length and also the no longer needed pressed and thorn 26 separated pierced pipe ends.

10 shows an alternative solution in which within the preform 2 (here with two open pipe ends 8a , b) a hose 32 is inserted. The hose 32 Again, with its open ends at the two open ends of the tooling 14 with two plugs 34a , b closed or against the inner wall of the tooling 14 pressure-tight pressed. The stopper 34a contains an implementation 24 for the supply of overpressure pu , The hose 32 comes with the overpressure pu impinges and presses the preform 2 against the inner wall 16 of the production means 14 to accept its contour.

Alternatively, also on the hose 32 be waived so that the preform 2 even between the plugs 34a , b and the manufacturing equipment 14 pressure-tight is pressed. In other words, a tensioning of the hose takes place 32 or preform 2 through the plugs 34a , b, until a bilateral seal is reached.

11 shows the transformation to the air duct 18 by the effect of overpressure pu and heat W , Here is the production tool 14 Alternatively, another implementation 24 for negative pressure pu intended.

12 shows an alternative means of production 14 , Here also the plug 34b is provided with a passage.

13 shows an inserted preform 2 that is between the plugs 34a , b and the manufacturing equipment 14 pressure-tight compressed. Here is the preform 2 along the illustrated arrows through the bushings 24 in the stopper 34a , b flowed through with a pressure medium. The flow is thus under pressure pu , Again, an inner tube or hose is optional again 32 like in the 10 . 11 applicable. The medium, eg hot air or liquid, as a hot medium can also be equal to the heat input of the heat W on the preform 2 be used. The medium thus also serves to supply heat. The implementation 24 for the negative pressure pu may alternatively be omitted.

The flow can also after molding of the preform 2 to the air duct 18 (indicated by dashed lines) are maintained. Also, then a flow with cool or cooling medium is possible to harden the air duct 18 to enable.

LIST OF REFERENCE NUMBERS

2

preform

4

wall

6

inner space

8a, b

pipe end

10

connection means

12

Pressure supply means

14

manufacturing equipment

16

inner wall

18

Air guide tube

20

gap

22a, b

arrow

24

execution

26

mandrel

28

Press agent

30a, b

part

32

tube

34a, b

Plug

pu

overprint

pu

vacuum

W

warmth

I

length

Claims (15)

A method for producing an air duct (18) for an air duct system in an aircraft, characterized in that - a preform (2) for the desired air duct (18) is provided, wherein the preform (2) one of a wall (4) at least tube-like enclosed interior (6), - the preform (2) in a manufacturing means (14) is introduced, the inner wall (16) is formed according to a desired outer contour of the air duct tube (18), or the preform (2) to a manufacturing means (14 ) is arranged around, whose outer wall is formed according to a desired inner contour of the air guide tube (18), - for an inner preform (2) of the interior (6) of the preform with overpressure (pü) and / or a gap (20) between the wall (4) of the preform (2) and the inner wall (16) of the manufacturing means (14) with negative pressure (pu) is applied, or for an external preform (2) the external space of the preform is subjected to overpressure (pu) and / or a clearance (20) between the wall (4) of the preform (2) and the outside wall of the production means (14) is subjected to negative pressure (pu), - the preform (2 ) at least by the action of the pressure (pu, pü) to the inner wall (16) or outer wall of the manufacturing means (14) applies and thereby to the air guide tube (18) is formed. - The air duct (18) is removed from the production means (14). Method according to Claim 1 characterized in that the preform (2) during the application of excess pressure (pü) and / or negative pressure (pu) in the manufacturing means (14) in addition to heat (W) is applied. Method according to Claim 2 characterized in that the air guide tube (18) is cooled before removal from the production means (14). Method according to one of the preceding claims, characterized in that the air guide tube (18) after removal from the production means (14) is finished. Method according to Claim 4 characterized in that the air duct (18) is finished to be trimmed at at least one of its pipe ends (8a, b). Method according to one of the preceding claims, characterized in that a cylindrical preform (2) is provided. Method according to one of Claims 1 to 6 , characterized in that a preform (2) is provided which is open at one end of the tube (8b) and closed at the other end of the tube (8a). Method according to one of Claims 1 to 6 , characterized in that a preform (2) is provided which is open at both pipe ends (8a, b). Method according to one of the preceding claims, characterized in that a preform (2) is provided which is an extrudate and / or a rod product. Method according to one of the preceding claims, characterized in that at least one of the open tube ends (8a, b) of the preform (2) before the loading of the preform (2) with the overpressure (pü) and / or negative pressure (pu) by pressing between Parts (30a, b) of the manufacturing means (14) is closed. Method according to one of the preceding claims, characterized in that an open tube end (8a, b) of the preform (2) is closed with a closure means before being exposed to the overpressure (pü) and / or underpressure (pu). Method according to one of the preceding claims, characterized in that an overpressure (pü) in the interior space (6) is produced in that the wall (4) is penetrated by a pressure supply means (12) pressure-tight. Method according to one of the preceding claims, characterized in that an overpressure (pü) in the inner space (6) is generated in that it is introduced via one of the open tube ends (8a, b) of the preform. Method according to one of the preceding claims, characterized in that the preform (2) is provided by being selected from an assortment of preforms (2). Method according to Claim 14 , characterized in that the preform (2) is selected from an assortment whose preforms (2) differ in terms of their length and / or cross-section and / or wall thickness.

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