Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C33/00—Moulds or cores; Details thereof or accessories therefor
  • B29C33/44—Moulds or cores; Details thereof or accessories therefor with means for, or specially constructed to facilitate, the removal of articles, e.g. of undercut articles
  • B29C33/48—Moulds or cores; Details thereof or accessories therefor with means for, or specially constructed to facilitate, the removal of articles, e.g. of undercut articles with means for collapsing or disassembling
  • B29C33/50—Moulds or cores; Details thereof or accessories therefor with means for, or specially constructed to facilitate, the removal of articles, e.g. of undercut articles with means for collapsing or disassembling elastic or flexible
  • B29C33/505—Moulds or cores; Details thereof or accessories therefor with means for, or specially constructed to facilitate, the removal of articles, e.g. of undercut articles with means for collapsing or disassembling elastic or flexible cores or mandrels, e.g. inflatable
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/28—Shaping operations therefor
  • B29C70/40—Shaping or impregnating by compression not applied
  • B29C70/42—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles
  • B29C70/46—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles using matched moulds, e.g. for deforming sheet moulding compounds [SMC] or prepregs
  • B29C70/48—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles using matched moulds, e.g. for deforming sheet moulding compounds [SMC] or prepregs and impregnating the reinforcements in the closed mould, e.g. resin transfer moulding [RTM], e.g. by vacuum
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/28—Shaping operations therefor
  • B29C70/30—Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core
  • B29C70/34—Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core and shaping or impregnating by compression, i.e. combined with compressing after the lay-up operation
  • B29C70/345—Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core and shaping or impregnating by compression, i.e. combined with compressing after the lay-up operation using matched moulds
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/28—Shaping operations therefor
  • B29C70/30—Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core
  • B29C70/36—Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core and impregnating by casting, e.g. vacuum casting
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/28—Shaping operations therefor
  • B29C70/40—Shaping or impregnating by compression not applied
  • B29C70/42—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles
  • B29C70/44—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles using isostatic pressure, e.g. pressure difference-moulding, vacuum bag-moulding, autoclave-moulding or expanding rubber-moulding
  • B29C70/443—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles using isostatic pressure, e.g. pressure difference-moulding, vacuum bag-moulding, autoclave-moulding or expanding rubber-moulding and impregnating by vacuum or injection
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/28—Shaping operations therefor
  • B29C70/40—Shaping or impregnating by compression not applied
  • B29C70/42—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles
  • B29C70/44—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles using isostatic pressure, e.g. pressure difference-moulding, vacuum bag-moulding, autoclave-moulding or expanding rubber-moulding
  • B29C70/446—Moulding structures having an axis of symmetry or at least one channel, e.g. tubular structures, frames
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/28—Shaping operations therefor
  • B29C70/54—Component parts, details or accessories; Auxiliary operations, e.g. feeding or storage of prepregs or SMC after impregnation or during ageing
  • B29C70/541—Positioning reinforcements in a mould, e.g. using clamping means for the reinforcement
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D23/00—Producing tubular articles
  • B29D23/001—Pipes; Pipe joints
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B30—PRESSES
  • B30B—PRESSES IN GENERAL
  • B30B5/00—Presses characterised by the use of pressing means other than those mentioned in the preceding groups
  • B30B5/02—Presses characterised by the use of pressing means other than those mentioned in the preceding groups wherein the pressing means is in the form of a flexible element, e.g. diaphragm, urged by fluid pressure
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/06—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts
  • B29K2105/08—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts of continuous length, e.g. cords, rovings, mats, fabrics, strands or yarns
  • B29K2105/0872—Prepregs
  • B29K2105/089—Prepregs fabric
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2307/00—Use of elements other than metals as reinforcement
  • B29K2307/04—Carbon
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2023/00—Tubular articles
  • B29L2023/22—Tubes or pipes, i.e. rigid
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2031/00—Other particular articles
  • B29L2031/30—Vehicles, e.g. ships or aircraft, or body parts thereof
  • B29L2031/3076—Aircrafts
  • B29L2031/3082—Fuselages
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T50/00—Aeronautics or air transport
  • Y02T50/40—Weight reduction

Definitions

• the present invention relates to a method and an apparatus for producing a tubular structural component, in particular a hulled sun section of an aircraft or spacecraft.
• a hulled sun section based on fiber composite materials is produced by means of a wound body as a positive tool, wound onto the layers of a fiber material prepreg impregnated with a resin matrix, and then cured, eg by a heat treatment.
• the fiber placement (fiber placement) or winding process is very time-consuming due to the size of the component and different fiber directions of the prepreg layers. Since even small deviations in the diameter of adjacent hull sunshine sections can hinder the final assembly, the winding body must have a high dimensional accuracy and may no longer expand after the fiber laying process, for example during a heat treatment.
• the bobbin divisible or collapsible, so that it can be shrunk after the curing process by dividing or collapsing inwards and removed from the hull sun section.
• the provision of a bobbin that combines these properties is associated with high costs.
• pressure plates are additionally placed for the curing process.
• the pressure plate and prepreg 'lege no auxiliary material such. Tear off or venting fabric, as this would lead to a rough surface of the hull sun section.
• the thickness of the prepreg fabric during the curing process is reduced by the so-called settling path, which has to be taken into account in the shaping and pressing of the printing sheets.
• the setting path of the prepreg material may vary depending on the material charge and thus become the cause of porosity in a batch with a relatively large settling path. Since the inner diameter of the hulled sun section is fixed by the outer diameter of the wound body, the outer diameter of the hulled sun section is reduced during the gradual setting of the prepreg layer. The prepreg gel is thus pushed together in the circumferential direction of the section, which easily leads to undesirable waviness of the fibers.
• this object is achieved by a method for producing a tubular structural component having the features of patent claim 1 and by a device for producing a tubular structural component having the features of patent claim 14.
• tubular molding tool which is designed as a negative tool, ie has an inner molding surface which represents a negative of the outer surface of the structural component to be formed.
• tubular w is not limited to tubes having circular cross-sections, but explicitly includes tubes having elliptical, rectangular or other arbitrarily shaped cross-sections, the cross-section need not be constant over the length of the tube, but narrow, widen or otherwise deform.
• a support which is expandable, ie, which can be selectively brought at least into an expanded and an unexpanded state.
• the carrier In the unexpanded state, the carrier has a shape which is smaller than the space circumscribed by the inner surface of the mold, so that the carrier can be arranged in this state inside the mold. It remains between the inner surface of the mold and an outer surface the carrier a minimum distance, which should be referred to here as the expansion distance.
• the outer surface of the carrier lying opposite the outer surface of the carrier when the carrier is arranged in the mold of the inner surface of the mold serves as a carrier surface which carries the fiber fabric to be processed during the manufacturing process.
• the fiber fabric is provided in tubular form and placed on the support surface so that the support surface is covered by the tubular scrim. For example, the tubular fiber web is pulled over the carrier while it is freely accessible outside the mold in the unexpanded state.
• the carrier is then arranged in the mold, that the area covered by the tubular unwoven scrims Suflä ⁇ surface of the inner surface of the mold opposite to said remains between the fiber fabric and the 'inner surface of the reduced by the thickness of the fiber lay expansion spacer.
• the carrier is then expanded, whereby this remaining distance shrinks to zero and the fiber layer is pressed by the carrier surface ⁇ the expanded carrier against the inner surface of the mold.
• the fiber fabric held between the support surface and the inner surface of the mold is infiltrated with a hardenable matrix.
• the use of a negative tool, which maps the outer contour of the hull sun section, makes it possible to comply with the desired external dimensions with high accuracy.
• the mold can be made without great constructive effort in one piece o- in a simple way to the outside hinged or dismountable.
• the construction of the fiber scrim independently of the forming and curing tool on the carrier enables to provide a plurality of carriers suitable for a given forming tool and to feed one of the carriers outside the forming tool with a layer of fiber during one layer other carrier is for curing in the mold. In this way, mold and optionally a curing station can be used continuously, which reduces the production costs and shortens waiting times.
• fiber fabric which is infiltrated with a separately provided matrix, offers advantages over the conventional use of the prepreg further time savings and greater freedom in the structural design of the Herge ⁇ presented structural components. Since the fiber fabric is stretched by the expansion of the carrier in the circumferential direction, fiber baffles are avoided.
• the expansion distance is between 1 and 10 cm, e.g. about 5 cm. At such a distance, sufficient clearance remains between the support surface and the inner surface of the mold to move the support into and out of the mold particularly quickly and non-contact while avoiding overstretching of the tubular scrim during expansion.
• the covering of the carrier surface takes place in such a way that fibers of a fiber layer of the fiber fabric extend diagonally around the carrier.
• the tubular fiber layer has a greater length than the structural component, so that, when the carrier expands radially, the fiber layer can contract in its longitudinal direction without incomplete coverage of the carrier surface.
• the support comprises a pressure membrane, wherein the expansion of the support by generating a pressure difference between an inner region of the carrier and an intermediate region between the pressure membrane and the mold takes place.
• the pressure membrane exerts over the entire inner surface of the tubular mold a uniform, by means of the pressure difference precisely adjustable contact pressure on the tubular Fasergelege, which allows a particularly uniform shaping of the wall of Strukturbau ⁇ part.
• the pressure in the interior of the carrier is increased beyond the atmospheric pressure.
• Suitable compression devices can be accommodated in the interior of the carrier, so that when the carrier is arranged in the mold, the carrier can be expanded without sealing, for example, the intermediate region.
• Alternatively, or in addition to generating the pressure difference of the pressure in the Swissbe ⁇ is lowered area between the pressure membrane and the molding tool under the atmospheric pressure. This allows, make the rich for indoor ⁇ eg accessible for inspection to.
• the pressure membrane does not need to be designed for high absolute pressures.
• a step of arranging a stiffening element between the support surface and the fiber layer is further provided.
• the stiffening element e.g. a stringer to connect to the structural component.
• the stiffening element is guided in at least one guide slot extending in a radial direction of the tubular forming tool.
• the stiffening element is precisely guided without tilting to the desired tethering position.
• the stiffening element is arranged as pre-soaked or unimpregnated semi-finished fiber product between the support surface and the fiber layer. By jointly infiltrating the stiffening element and the wall of the tubular structural component as well as by co-curing, the stiffening element is connected.
• the stiffening element is arranged as a precured semi-finished fiber product between the support surface and the fiber layer. This allows the co-bonding of the stiffening member to the wall of the tubular structural member, e.g. the curable matrix, which infiltrates the tubular fiber web, serves as an adhesive.
• the stiffening element is arranged in a correspondingly formed recess of the carrier surface. This facilitates the loading of the carrier with the stiffening element.
• a placeholder is arranged in a cavity between the stiffening element and the tubular fiber layer.
• This placeholder holds during the curing process when the Versteifungsele ⁇ element is exposed to the mutual pressure of the carrier surface and the inner ⁇ surface of the mold, the desired cavity of the stiffening element free.
• the placeholder comprises a membrane sheath, further comprising a step of expanding the placeholder by increasing a pressure in the membrane sheath. Such an expandable placeholder can be shrunk again after the curing process and therefore easily removed.
• At least one guide cover for attachment to at least one end of the mold and / or the Trä ⁇ gers is provided.
• the guide cover has a extending in a ra ⁇ Dialen direction of the tubular forming tool guide slot to guide the stiffening element. Through the guide slot, the stiffening element is guided precisely in the radial direction to the desired position on the inside of the structural component during the expansion of the carrier, regardless of its shape and the shape of the support surface.
• FIGS. 1A-C are schematic perspective views of an apparatus for producing a hull sun section of an aircraft according to a first embodiment of the invention
• FIGS. 2A-G are fragmentary cross-sectional views of a device according to a second embodiment, in the manufacture of a tubular structural component.
• 3A-D are fragmentary cross-sectional views of a device according to a third embodiment, in the manufacture of a tubular structural component.
• FIGS. 1A to 1C show, in three schematic perspective views, an apparatus for producing a hulled sun section of an aircraft, wherein in each of the three figures different steps of a production method are illustrated.
• the hull section to be produced has approximately the shape of a cylinder jacket, the cross section typically deviates from the ideal circular shape and changes over the length of the section.
• FIG. 1A Shown in FIG. 1A is a tubular forming tool 102 having an inner surface 106 shaped according to the desired shape of the outer surface of the hulled barrel section to be produced.
• the mold 102 is a so-called negative tool, since its inner surface 106 forms a negative ⁇ tivform to the outer surface of the hull sunshine section.
• the carrier 110 is approximately cylindrically shaped, about the same length as the forming tool 102, and having an outer diameter that is slightly less than the inner diameter of the forming tool. As a result, it can be arranged both within the mold 102 and outside.
• the carrier 110 comprises an inner framework defining the shape shown, and is coated on its lateral surface 108 with a resilient pressure membrane which separates an inner region of the carrier pressure-tight from the outer space.
• the support and / or the molding tool may be e.g. be provided with roles not shown here.
• the surface of the pressure membrane arranged around the lateral surface 108 of the approximately cylindrical carrier 110 forms a carrier surface 108 which carries the tubular fiber web 114 in the production of the hulled sun section.
• the carrier 110 is placed outside of the mold 102.
• the tubular fiber web 114 is cut to size and pulled over the carrier 110 until it completely covers the carrier surface 108.
• a nonwoven scrim such as so-called NCF (non-crimped fabric) made of carbon fibers or other suitable fibers, which can be locally reinforced in accordance with design details of the fuselage section to be produced, is used as the scrim 114.
• the fiber web 114 comprises a plurality of fiber layers.
• fibers 116 as shown by way of example diagonal, ie helically extend around the circumference of the support 110.
• fibers extend at different angles of inclination diagonally or parallel to the longitudinal direction of the carrier 110.
• the length 118 of the cut tubular fiber fabric 114 is greater than the length of the carrier 110 and the forming tool 102 so that the fiber web 114 not only covers the carrier surface 108 of the carrier 110, but also protrudes beyond the carrier 110.
• Figure IB shows a subsequent step of the manufacturing process in which the carrier 110 covered by the fiber web 114 has been moved into the forming tool 102. Since the diameter of the carrier 110 is smaller than the inner diameter of the mold 102, the carrier 110 fits into the mold 102 without the support surface 108 contacting the inner surface 106 of the mold. Rather, the support surface 108 and the inner surface 106 of the mold 102 are approximately parallel, with a minimum distance 112 of, e.g. 5-10 cm remains. Because of its length 118, the fiber covering 114 covering the support surface 108 projects out of the molding tool 102 on both sides.
• FIG. 1C shows a further step of the production method in which an overpressure was generated in the interior of the carrier 110 by means of a compressor 205.
• the support membrane forming the pressure membrane of the carrier is inflated by the pressure, so that the carrier 110 is radially expanded beyond the dimensions of its inner framework. Due to the radial expansion of the carrier 110, the tubular fiber web 114 is stretched in the direction of the circumference of the carrier 110. At the same time, it has contracted in its longitudinal direction to a shortened length 119 due to the fibers 116 extending diagonally around the carrier.
• the tubular fiber web 114 was initially just as rich Tailored that it covers the support surface even with the shortened length.
• the pressure membrane presses the fiber web 114 against the inner surface 108 of the mold due to the overpressure in the inner region of the carrier 110.
• the fiber web thus fixed is infiltrated with a liquid, curable resin matrix 115, e.g. by filling the resin matrix into the space between the pressure membrane and the molding tool 102 from one end of the molding tool 102, as indicated by arrows.
• the resin matrix is cured, e.g. through a heat treatment.
• the overpressure is released from the interior of the carrier 110 so that the carrier 110 returns to its original, unexpanded state and can be easily removed from the forming tool 102.
• the finished hull pulley section is removed from the mold 102. Sections tapering towards an end are e.g. taken in the direction of the other end of the mold 102.
• the molding tool 102 may be made in two or more parts, so that it can be opened to remove the finished section.
• FIGS. 2A-G show, respectively, for different process steps a section of the periphery of the Trä ⁇ gers 110 in Quer ⁇ chnittsansicht.
• FIG. 2A shows the aforementioned section of the carrier 110 in an initial state in which no fiber layer is still arranged on the carrier surface 108 and the carrier 110 is located outside of the forming tool 102.
• the carrier 110 includes fully a rigid support frame 111 with a substantially circular ⁇ shaped cross section.
• the carrier framework 111 is made of aluminum, for example. formed minium and has on its surface a plurality of small holes for pressurization with negative pressure and / or overpressure, which are not shown here for clarity.
• a slot-like recess 210 for receiving a later Ver ⁇ steifungselements is formed.
• the circumference of the support frame 111 is flattened.
• the surface of the support frame 111 is covered by a pressure membrane 200 which extends over the entire lateral surface of the approximately cylindrical support frame 111 as a whole and is pressure-tightly connected to the surface of the support frame 111 at the edges of the lateral surface. Between the pressure membrane 200 and the support frame 111, an inner region 202 is thus pressure-tight with respect to the outer space completed.
• the pressure membrane 200 is e.g. designed as a plastic film.
• Figure 2B shows a state of the carrier 110 of Fig. 2A, after a vacuum pump 204 through the fine holes 213 in the surface of the support stand 111, of which only a single bore 213 is shown here as an example, has been connected to the inner ⁇ space 202 and has evacuated this. Due to the negative pressure in the interior 202, the pressure membrane has been sucked tightly against the support frame 111. In particular, the pressure membrane of the contour of the support framework 111 follows well into the deepening Ver ⁇ 120th
• Fig. 2C is now a stiffening element 208 with T-shaped profile, as used for example in aircraft as a so-called T-stringer, has been inserted into the recess 120.
• the horizontal bar 209 of the T-profile lies inside ⁇ half of the flattening 211 on the be ⁇ from the pressure membrane 200 ⁇ covered support frame 111.
• the pressure membrane 200 is separated from a tubular fiber web 114 has been covered by carbon fibers.
• the outer surface 108 of the pressure membrane 200 functions as the carrier surface 108 of the carrier 110 supporting the fiber web 114.
• the reinforcing element 208 is trapped between the carrier surface 108 and the fiber web 114 and held within the recess 210. Since also the horizontal bar 209 of the T-profile is hidden within the flattening 111, the fiber layer 114 above the stiffening element 208 has no bulge, but follows a gentle curvature.
• FIG. 2E shows the carrier 110 thus prepared and loaded with the stiffening element 208 and the fiber web 114 after it has been pushed into a tubular forming tool 102.
• the support 110 is so far smaller than the interior of the mold 102 and formed according to its shape that between its support surface 108 and the mold surface 106 of the mold always a distance 112 remains. In other words, the support surface 108 and the molding surface 106 in the state shown parallel to each other at a distance 112 to each other.
• the fiber web 114 and the pressure membrane 200, as well as the pressure membrane and the support frame 111 contact one another and are shown spaced apart only for the sake of clarity in FIGS. 2B-E.
• FIG. 2F shows the support 110 arranged in the molding tool 102 after the interior space 202 has been connected between the support frame 111 and the pressure membrane 200 with a compressor 205 and subjected to overpressure by the fine bores 203.
• the overpressure has inflated the pressure membrane 200 so that it is expanded in the radial direction 212 as far as the shaping surface 106 of the molding tool 102.
• Both the pressure membrane and the fiber fabric have been stretched by the expansion.
• the stiffening element 208 and the fiber web 114 have been guided through the expanding pressure membrane 200 to the molding surface 106 and are in the state shown with uniform, given by the excess pressure against this pressed.
• the stiffening element 208 has been guided during the expansion process through the recess 120 in the radial direction 112 and is held even in the shown state still in the recess 120 as in a Pntonungsschlitz and thus precisely positioned.
• Figure 2G shows a state after the space between the pressure membrane 200 and the mold 102 has been filled with a curable matrix system 115.
• the matrix 115 has infiltrated both the fiber fabric 114 and the fibrous material of the stiffener 208 as indicated by hatching.
• the overpressure in the inner region 202 of the carrier 110 is maintained. Subsequently, the overpressure is omitted and the finished hull sun section 100 removed from the mold 102.
• FIG. 3A-D Yet another embodiment of the manufacturing method is shown in Figure 3A-D.
• the figures again show a section of the periphery of the carrier 110 in cross-sectional view, in each case for different method steps.
• FIG. 3A shows a condition corresponding to FIG. 2B, in which a pressure membrane 200 has been arranged tautly along the surface of a carrier framework 111, e.g. also by evacuating the intervening interior of the wearer.
• a recess 120 is formed in the support frame 111 for a stiffening element, which, however, here has the shape of a wide, trapezoidal trough.
• a stiffening element 208 formed of prepreg O-profile has been disposed in the recess 210 in the recess 120.
• a cavity 304 to be formed in the finished hull sun section under the O profile of the stringer 208 is here filled by a placeholder 300, which is formed here by way of example from a membrane sleeve 301 filled with compressed air.
• a tubular fibrous web 114 covers the support surface 108 formed by the pressure membrane 200, the foot portions 306 of the O-stringer, and the outwardly facing side of the spacer 300.
• the thus prepared carrier 110 was placed in a tubular die 102. Between the support surface 106 and the mold surface remains as in the above-described imple mentation form an expansion distance 112.
• a guide pin 502 is anchored in the placeholder 300 at the two ends of the O-stringer 208. This slides in a radially 212 extending guide slot 302 which is recessed in a respectively attached to the ends of the mold 102 witnessessdecke1 500.
• FIG. 3D shows a state in which, due to the applied pressure difference between inner 202 and intermediate region 206, the pressure membrane presses the tubular fiber web 114, together with the O-stringer 208 and the included spacer 300, against the inner surface 106 of the molding tool 102.
• the fiber web 114 and the O-stringer 208 are infiltrated and cured together with a resin matrix.
• the introduced matrix and the resin material contained in the prepreg of the O-stringer 208 connect.
• the overpressure in the inner region 202 or the negative pressure in the intermediate region 206 are discharged and the hardened hulled sun section is removed from the forming tool 102.
• the blank holder 300 after the overpressure in its interior has also been discharged, is removed below the O-stringer 208, around its cavity 304 release.
• stiffening elements of a variety of other profiles can be used.
• Hull pulley sections and other tubular structural components with complex, tapered cross-sections, door and window openings can be made.

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• Engineering & Computer Science (AREA)
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• Composite Materials (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Moulding By Coating Moulds (AREA)
• Casting Or Compression Moulding Of Plastics Or The Like (AREA)

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• 2007
  • 2007-12-13 DE DE102007060029A patent/DE102007060029A1/de not_active Ceased
• 2008
  • 2008-11-12 EP EP08860048.1A patent/EP2229273B1/de not_active Not-in-force
  • 2008-11-12 CN CN200880120453.0A patent/CN101896329B/zh not_active Expired - Fee Related
  • 2008-11-12 RU RU2010122662/05A patent/RU2488488C2/ru not_active IP Right Cessation
  • 2008-11-12 CA CA2707802A patent/CA2707802A1/en not_active Abandoned
  • 2008-11-12 BR BRPI0821246-5A patent/BRPI0821246A2/pt not_active IP Right Cessation
  • 2008-11-12 JP JP2010537352A patent/JP2011506136A/ja active Pending
  • 2008-11-12 WO PCT/EP2008/065355 patent/WO2009074419A1/de not_active Ceased
• 2010
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• 2014
  • 2014-05-23 US US14/285,704 patent/US9180628B2/en not_active Expired - Fee Related
• 2015
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