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
  • 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
  • B29C70/56—Tensioning reinforcements before or during shaping
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B11/00—Making preforms
  • B29B11/14—Making preforms characterised by structure or composition
  • B29B11/16—Making preforms characterised by structure or composition comprising fillers or reinforcement
• • 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
  • B29C70/38—Automated lay-up, e.g. using robots, laying filaments according to predetermined patterns
  • B29C70/382—Automated fiber placement [AFP]
• • 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
  • 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
  • B29C2793/00—Shaping techniques involving a cutting or machining operation
  • B29C2793/0027—Cutting off
• • 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
  • B29C2793/00—Shaping techniques involving a cutting or machining operation
  • B29C2793/0081—Shaping techniques involving a cutting or machining operation before shaping
• • 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
  • B29C70/06—Fibrous reinforcements only
  • B29C70/10—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres
  • B29C70/16—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length
  • B29C70/20—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length oriented in a single direction, e.g. roofing or other parallel fibres
  • B29C70/205—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length oriented in a single direction, e.g. roofing or other parallel fibres the structure being shaped to form a three-dimensional configuration
  • B29C70/207—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length oriented in a single direction, e.g. roofing or other parallel fibres the structure being shaped to form a three-dimensional configuration arranged in parallel planes of fibres crossing at substantial angles

Definitions

• the invention relates to an apparatus for the production of fiber preforms, which in particular constitute a precursor in the production of fiber-reinforced plastic components, the apparatus having a plurality of unwinding stations for providing a plurality of yarns or rovings, a plurality of grippers, each having one or more yarns or rovings on its Beginning, and having at least a first forming tool, each gripper being reciprocally movable on a path between a maximum position and a picking position, and wherein the picking position is provided at a yarn transfer point and closer to the unwinding station than the maximum position.
• the invention relates to a method, in particular using the device, for the production of fiber preforms, which for example represent a precursor in the production of fiber-reinforced plastic components, which comprises the following method steps in succession:
• Fiber-reinforced plastic consists of matrix material, which among other things gives the rigidity and of fibers, which are embedded in the matrix material and which among other things provide the tensile strength. Fiber-reinforced plastic is used especially for heavily loaded components, which should still be as light as possible. Since the fibers impart no strength in the transverse direction, the fibers must be oriented so that their longitudinal direction with the respective Strain as well as possible matches. To achieve this, the fibers often have to be laid in different directions. The better and more precisely the fiber layer is adapted to the load, the better the component will be. For components made of fiber-reinforced plastic, there are numerous manufacturing processes. For the production of large numbers of well-applicable methods, however, there are currently only with rotationally symmetrical or plate- or strand-shaped components by winding or plate or extrusion.
• Fiber preforms are first produced corresponding to the desired three-dimensional component shape, so-called preforms, which predominantly consist of fibers which are often arranged one above the other in several layers in order to achieve the necessary fiber directions. Subsequently, the fiber preforms are then soaked or coated with the matrix material, sometimes pressed and finally cured. Both for the production of the fiber preforms and for the impregnation and / or curing of the components molding tools can be used according to the desired component shape, on or in which the Faservorform ling or the component is placed and / or pressed.
• the fiber preforms In order for the fiber preforms to have sufficient dimensional stability for further processing, they are provided with small amounts of adhesive or binder and fixed after three-dimensional draping, e.g. by drying or by heating and cooling.
• the fiber preforms are usually created by superimposing and fixing of prefabricated and pre-bonded flat semi-finished products.
• Such semi-finished products are for example tapes or fabrics, scrims or nonwovens in which a multiplicity of individual yarns or rovings are already woven, sewn or glued into a flat structure.
• continuous fibers ie when the fibers from a coil or from a Balls are handled.
• yarn bundles or rovings are called yarn bundles or rovings.
• the rovings can consist of up to several ten thousand single yarns, which are also called filaments.
• the required individual parts are cut from the flat semifinished product, which is usually available as a roll product, according to a kind of pattern, as is known from DE 10 2008 011 658 A1. Then they are placed over a mold and connected or pressed together. An example of the production of such semi-finished products by gluing or sewing is also shown in DE 10 2008 01 1 658 A1. Often, however, a high proportion of manual activities is necessary.
• a device for the mechanical production of simple one-dimensionally curved preforms with sections of semifinished products, which are held in a cassette and then deposited on a core, is known from DE 10 2008 042 574 A1. More complex shapes can not yet be produced mechanically.
• the object of the invention is to provide an apparatus and a method for the production of fiber preforms, so that even more complex, high-quality structures easier to automate, but flexible in shape and fiber orientation, faster and cheaper to manufacture.
• the device is characterized in that the first mold has a draping position in the region of the connecting lines between the maximum positions and the yarn transfer points and a Abfahrposition outside the connecting lines and that the first mold is rotatable and / or tiltable at least in the Abfahrposition and in rotated and / or tilted position can be moved to the respective draping position.
• a plurality of yarns or rovings can be stretched simultaneously by simple, in particular linear, paths for the grippers and, nevertheless, several layers with different orientations can be draped one after the other on the molding tool. Both the unwinding stations and the yarn guide through the grippers can remain stationary.
• the desired layer orientation with regard to the later component can be achieved by the rotation of the molding tool.
• the device is thereby designed to be suitable for a take-off rate of more than 2 kg / min or even more than 3 kg / min of yarn or roving material.
• a second mold is provided, which can be merged with the first mold in the draping position and has its own departure position.
• the second mold as seen from the first mold, arranged on the opposite side of the spanned yarns or rovings.
• the movement into the draping position can preferably take place simultaneously with or after the first forming tool for the second forming tool. But it can also be done before the first mold.
• the first and / or second mold can also be designed in several parts.
• the direction of movement between the lowered position and the draping position of the first and / or a second forming tool should preferably be arranged substantially perpendicular to the paths of the grippers.
• a deviation of up to +/- 30 ° is conceivable.
• the paths of the grippers are preferably approximately horizontal and the direction of movement of the forming tool approximately vertical. For both directions, a deviation of up to +/- 30 ° is also conceivable.
• the paths of the grippers preferably approximate the tensioned yarns or rovings prior to draping.
• the second molding tool is also rotatable and / or tiltable at least in the retraction position and can be moved into the draping position in a rotated and / or tilted position.
• the rotation and / or tilting is carried out in accordance with that of the first mold.
• the second molding tool can be matched with the first one.
• the second mold is designed as a hood which fits over the first mold and leaves a gap for the yarns or rovings between the first and second molds. This will bring the yarns or rovings exactly in the desired shape, that is draped.
• a clamping device is provided for adjusting and / or regulating the voltage.
• a tensioning device which can hold the tension during draping constant or in a predetermined value range.
• the axis of rotation of the first and / or of a second molding tool may be substantially perpendicular to the paths and substantially parallel to the direction of movement between the lowered position and the draping position of the first and / or second molding tool.
• the first and / or a second molding tool can be equipped with a heating device and / or a pressing device.
• a heating device and / or a pressing device By increasing the temperature or pressure, an existing binder can be activated, so that the yarns or rovings are fixed in the predetermined shape and connected to one another first to a layer and then to the fiber preform.
• a binder material for example, threads or nonwovens, which consist at least partially of thermoplastic or adhesive, are draped with. As a result, the binder material necessary for fixing is applied directly to the fiber material.
• the binder material can also be introduced by hybrid threads, which also contain binder material in addition to fiber material, or by coating or spraying the yarns or rovings.
• the binder material may also be applied, for example sprayed, onto a forming tool after draping the yarns and rovings.
• a certain stability is achieved for the application of another layer of yarns or rovings or for the further processing of the fiber preform.
• the first and / or a second mold can be easily separable attached to a moving device, in particular a lifting table or a lowering device.
• a moving device in particular a lifting table or a lowering device.
• the feeding of the device with yarns or rovings takes place from the unwinding stations.
• the unwinding stations can be designed, for example, as a so-called creel.
• the yarns or rovings can be drawn from bobbins or bobbins.
• Each yarn transfer point receives yarn or rovings from one or more unwind stations.
• a separating device which can separate the yarns or rovings between a forming tool and the grippers, and / or a separating device which can separate the yarns or rovings between a forming tool and the yarn transfer points.
• the grippers can take various individual intermediate positions on their path and they can hold the respective beginnings of the yarns or rovings at these intermediate positions. As a result, different shapes can be simulated. And only as much yarn is stretched by each gripper as required for the corresponding position of the mold. It is also of advantage if the individual grippers of an outer contour of a molding tool can be positioned following their path. This means that the grippers hold the beginnings of the yarns or rovings so that they are as close as possible to the point where the fiber preform will have its edge where the yarns are separated after molding on the mold.
• the grippers are thus positioned where the respective yarns or rovings leave the mold when it is in the Position was moved to molding, or in multi-part molds when the molds were collapsed. As a result, very little waste of expensive fiber material is produced even in complex structures, which is particularly important in mass production.
• the method is characterized in that the draping takes place in each case by driving the first mold into the area of the tensioned yarns or rovings and that the first mold is rotated after separating the yarns or rovings of the first layer and before draping the further layer / or tilted.
• the clamping takes place in such a way that several separate grippers grip individual or several yarns or rovings at several yarn transfer points assigned to the individual grippers, that the grippers are then moved relative to one another on essentially parallel paths, and that the yarns or rovings thereby be stretched side by side. Furthermore, it is advantageous if several grippers can be moved simultaneously and independently of each other in a clamping operation. As a result, the yarns or rovings can be clamped in parallel quickly and yet each gripper can work independently.
• the rotation is about an axis that is substantially perpendicular to the tensioned yarns or rovings and substantially parallel to the direction of movement when driving in.
• the first mold is rotated by an angle between 10 and 170 °, preferably between 30 and 150 °, particularly preferably between 45 and 135 °.
• the second mold can be at an angle between 10 and 170 °, preferably be rotated between 30 and 150 °, more preferably between 45 and 135 °.
• each layer can be fixed after draping, in particular also the fiber preform after draping the last layer. This is done as mentioned, for example by activating the binder material.
• Fixing may begin directly during draping, that is, when the first or second forming tool is being driven in, or after.
• the separation of the yarns or rovings can take place during fixing or after fixing.
• a more accurate shaping is possible in that when draping a second mold, in particular a hood, is moved together with the first mold so that the respective layer is formed and optionally fixed.
• the same device for draping the first and the further layer can be used in each case. Between the draping of the layers, the mold is correspondingly rotated and / or tilted.
• the draping of the first layer takes place in a device, the first mold is then transferred to a further device and in the further device, the further layer is draped.
• the rotation and / or tilting of the mold with the layer located thereon can be done in the first or in the further device.
• several layers can be applied one behind the other in several devices until the fiber preform is finished.
• a layer is preferably applied and in particular also fixed in each device.
• Fig. 1a side view while gripper yarns or rovings fetches
• Fig. 1b shows top view while gripper yarns or rovings
• Fig. 2a side view after tensioning the yarns or rovings
• Fig. 2b Top view after tensioning the yarns or rovings
• FIG. 3b shows a plan view after a first draping step of the first layer.
• Fig. 4b top view after a second Drapier intimid the first layer
• Fig. 5a side view after the separation of the yarns or rovings
• Fig. 5b top view after the separation of the yarns or rovings
• Fig. 6a side view after turning the molds and pick up yarns or rovings for the second layer during gripper
• Fig. 6b Top view after turning the molds and pick up yarns or rovings for the second layer during gripper
• FIGS. 8a-c shows a top view after a second draping step of the second layer and in FIGS. 8a-c a further preferred embodiment of the device according to the invention in various method steps:
• Fig. 8a top view after application of the first layer
• Fig. 8c top view after applying yet another layer.
• the device is suitable for this purpose or the device performs the following method steps successively or partly parallel to one another:
• fibers such as e.g. made of carbon (carbon), glass, or aramid or other fibers.
• matrix material for the fiber-reinforced plastic e.g. thermoplastic or thermosetting plastic, epoxy resin, other plastic (polymers) or other resin in question.
• the binder material may be thermoplastic or adhesive. It may already be present as a hybrid or hybrid roving, i. individual fibers or yarns are made of binder material, or it can be spanned along with the yarns or rovings from the gripper or it is applied or sprayed onto the draped yarns or rovings.
• Fig. 1a and 1b the basic structure of the device can be seen.
• the supply of the yarns or rovings takes place over a multiplicity of Unwinding stations, in which the fiber material is provided in the form of coils or bobbins (so-called bobbins), and which are arranged in several rows 1, 2 next to each other, one behind the other or one above the other.
• the coils may also, as shown in Fig. 1a, form an upper and a lower row.
• the beginnings of the yarns or rovings 20 are shown schematically only in the respectively used area for the unwinding stations 3,4 used. All other beginnings are threaded to the corresponding yarn transfer points 14, so that they can be detected by the associated grippers in the pick-up positions 9. Such a thing is called together as a creel.
• the grippers 5 are shown in their maximum positions 8, which in this case also correspond to the starting positions.
• the clamping width of a gripper is b and the total clamping width of all grippers is B. Even if only equal width gripper are shown, of course, grippers with different widths are possible.
• the grippers do not necessarily have their maximum and pickup positions in a line.
• the second mold is not shown in plan view. And a corresponding movement or lowering device for the second mold is not shown separately.
• a gripper 6 is in pick-up position and fetches the yarns or rovings corresponding to its arrangement in the device by grasping their beginnings.
• the gripper is displaceable by a guide device 7, for example a linkage or a piston.
• the grippers can move individually, but only linearly and on parallel paths next to each other between the pick-up position and the maximum position, thus enabling simple automation and fast parallel movement.
• several unwinding stations can be combined into one group and assigned to a gripper.
• a gripper can grab several yarns or rovings together. In any case, at least as many unwinding stations as grippers should be provided.
• Fig. 2 a and 2 b represent the spanned yarns or rovings 21, which the gripper 10 has pulled out by the method in its intermediate position. This can be assisted by actively powered unwinding.
• the intermediate position is close to the outer contour of the molds or near the later position of the outer contour when the molds are brought into their draping position.
• Binder material 18, for example in the form of binder threads or binder webs, can also be stretched by the gripper together with the yarns or rovings. There may also be an upper and a lower row of unwind stations, as shown, so that the binder material is stretched between the upper and lower groups of yarns or rovings.
• the binder material When pulling out, the binder material can be preactivated in the area of the yarn transfer points 14, in particular by a heating device, so that the yarns or rovings are already somewhat fixed to one another at the beginning of draping.
• a spreading device can be provided in the area of the yarn transfer points, which can be designed as a kind of comb with one or more rows of tines. This ensures that the yarns or rovings lie next to each other across the board and do not slip sideways even during subsequent draping.
• the spreader may also be displaceable along the yarn paths or along the gripper paths. Another possibility for a yarn tension measuring device 13 is shown.
• Draping is the forming or shaping of yarns or rovings with the aid of a molding tool. Draping may be accomplished in one or more stages by moving the molding tool or dies simultaneously or sequentially into the plyed or roving ply. During draping, it is advantageous to regulate the yarn tensions, in particular to keep them constant. That is, as much yarn or roving is dispensed as is necessary for draping at the corresponding location of the forming tool. To achieve this, brake and coupling devices may be provided. Preferably, each unwinding station or each group of unwinding stations is assigned a corresponding control. This prevents the yarns or rovings from being overloaded or loosely laid. The yarn tensions can also be measured by suitable measuring devices in the area of the yarn transfer points and / or between the unwinding stations and the yarn transfer points. The value of the yarn tensions is preferably between 1 and 50 N / m 2 .
• Figs. 3 a and 3 b the state after the first draping is shown. From the lift table 17, the first mold 15 'was moved to the draping position. As a result, the yarns or rovings 22 are deflected and draped over the forming tool 15 '. The gripper 10 fixes the beginnings of the yarns near the outer contour of the molding tool 15 '. After this step, binder material or rovings can alternatively or additionally be applied or sprayed onto the yarns or rovings.
• the yarns or rovings are further draped using the second die 16 'that has been moved to its draping position (FIGS. 4 a and 4 b).
• the interaction of the two molds, between which the location of yarns or rovings is, a precise shape is possible.
• the molds can also be pressed together and one, preferably the second, or both molds can be heated, so that the binder material is activated and the yarns or rovings are dimensionally stable fixed to a layer.
• the separator may be connected to the first or second mold.
• the separated yarns or rovings 23 can be withdrawn and wound up again by means of a rewinding device or temporarily stored by appropriate yarn guidance.
• the rewinding takes place in such a way that again starts of the yarns or rovings in the area of the yarn transfer points 14 come to lie so that they can be picked up by the grippers without too much waste material being produced. Sensors can be used to record the beginnings.
• Fig. 6 a and 6 b show the first and second mold 15, 16 in a rotated position. Here they were turned 90 °. But it is also another angle of rotation, for example, about 30 °, 45 °, 60 °, or a tilt possible. The angle of rotation is preferably between 10 and 170 °. This depends on how and with which fiber orientation the further layer of yarns or rovings is to be applied.
• a further embodiment is shown, as for example in the manufacture of fiber preform lingen for hoods can be used.
• the used grippers 10.1 are at an intermediate position, the unnecessary grippers 5.1 are in the maximum position 8.1.
• On the first mold 15.1 a first layer of yarns or rovings is draped and fixed. The second mold is not shown.
• the stocking of the yarns or rovings takes place in the unwinding stations 1 .1, 2.1.
• a binder material supply 19.1 and the yarn transfer points 14.1 are present.
• the application of one or more further layers can take place in the same device or in one or more further devices according to the invention, to which the first molding tool is transferred together with the first layer.
• Fig. 8b another layer 26.1 is draped onto the rotated forming tool.
• the used grippers 1 1 .1 are along the outer contour of the mold and form it as accurately as possible. Narrower or different width grippers can be used for even more precise adjustment.
• Fig. 8 c shows how yet another layer was applied.
• the used grippers 12.1 are again along the outer contour. After fixing the layers together form the Faservorform ling 28.1.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Composite Materials (AREA)
• Robotics (AREA)
• Reinforced Plastic Materials (AREA)
• Moulding By Coating Moulds (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)

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• 2011
  • 2011-04-08 DE DE102011007021A patent/DE102011007021A1/de not_active Withdrawn
• 2012
  • 2012-01-27 CN CN201280017367.3A patent/CN103476560B/zh active Active
  • 2012-01-27 JP JP2014503036A patent/JP6000330B2/ja active Active
  • 2012-01-27 WO PCT/EP2012/051290 patent/WO2012136392A1/de not_active Ceased
  • 2012-01-27 EP EP12702787.8A patent/EP2694264B1/de active Active
• 2013
  • 2013-10-08 US US14/048,756 patent/US9694547B2/en active Active

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