DE102014222841A1 - Method for producing an at least approximately rotationally symmetrical fiber-plastic composite component with at least one axial undercut section - Google Patents

Abstract

A method for producing an at least approximately rotationally symmetrical fiber-plastic composite component having at least one axial undercut section is described. In this case, an at least approximately hollow-cylindrical fiber preform is first produced from at least one fiber, which is converted in a tool (9) into the final shape of the fiber-plastic composite component. Subsequently, the fiber preform impregnated with a thermosetting fluid plastic (17) is cured. The fiber preform is initially subjected to axial mechanical stress during its manufacture for clamping the at least one fiber and at least during the creation of the final shape of the fiber-plastic composite component in the tool (9) rotates together with the tool (9) and thereby to relax the mechanically relieved at least one fiber. According to the invention, the at least one fiber of the fiber preform is impregnated with a hardenable fluid plastic (17) in the tool (9) prior to the creation of the final shape of the fiber-plastic composite component.

Description

The invention relates to a method for producing an at least approximately rotationally symmetrical fiber-plastic composite component with at least one axial undercut section according to the closer defined in the preamble of claim 1. Art.

From the unpublished German patent application DE 10 2013 209 143.3 the applicant is both a method for producing a rotationally symmetrical fiber-plastic composite component, a device for performing such a method as well as a rotationally symmetrical fiber-plastic composite component known, wherein initially prepared during the process, a dry fiber preform and then the Fiber preform is processed in a pressure-assisted plastic injection process. During manufacture of the fiber-plastic composite component, the fiber preform is placed in a mold space formed between a tool and a radially inner tool surface and a tubular airtight membrane, and the tool and fiber preform are rotated about an axis of rotation to allow the fiber preform to abut the tool surface invests. Subsequently, the membrane is expanded, the mold cavity is evacuated and a plastic is injected into the mold cavity containing the fiber preform and, in turn, subsequently cured. The tool is rotated with the fiber preform at a predetermined minimum speed. In addition, it is proposed that the tool with the fiber preform is rotated at such a speed that the fiber preform can be deposited under the action of centrifugal force on the tool surface.

The disadvantage here is that the dry fiber preform deposits only to a limited extent on the tool surface and for the Ablegvorgang a correspondingly high speed of the tool and the fiber preform is provided, which in turn requires a high expenditure on equipment.

The present invention is therefore based on the object to provide a method for producing an at least approximately rotationally symmetrical fiber-plastic composite component, with which such a component can be manufactured in a simple manner.

According to the invention this object is achieved by a method having the features of claim 1.

In the method according to the invention for producing an at least approximately rotationally symmetrical fiber-plastic composite component having at least one axial undercut section, at least one approximately hollow fiber preform is first made from at least one fiber or from a plurality of fibers combined into a so-called roving the final shape of the fiber-plastic composite component is transferred. Subsequently, the impregnated with a curable fluid plastic fiber preform is cured. The fiber preform is initially axially mechanically loaded during its manufacture for tensioning the at least one fiber or the at least one roving combined fibers and at least during the creation of the final shape of the fiber-plastic composite component in the tool rotated together with the tool and thereby to Relaxing of at least one fiber or the at least one roving combined fibers mechanically relieved.

According to the invention, the at least one fiber or the fibers of the fiber preform combined at least into a roving are impregnated with the curable fluid plastic in the mold before the final shape of the fiber-plastic composite component is produced.

The impregnation according to the invention of the at least one fiber or of the fibers of the fiber preform combined into at least one roving prior to the production of the final shape of the fiber-plastic composite component in the tool leads with little effort to the fact that the prepreg, due to the higher total weight during the common rotation with the tool deposits to the desired extent on the tool surface on the fiber preform, without further measures, such as a pressurization or the like, spend.

The inventive method is suitable for producing any, approximately rotationally symmetrical hollow body with geometric undercut sections. It is possible to produce so-called bellows springs or tubular torsion elements of composite beam axles for vehicles by means of the method according to the invention.

In vehicles, axles or chassis for decoupling of the vehicle body from unevenness of the road or a rail with this resiliently connected. Usually spiral or coil springs, leaf springs or Luftbalgfedern be used, as well as so-called buffer made of elastomers or rubber are used as additional spring and pressure stop. Occasionally for this purpose, hydropneumatic suspensions are used, in which the resilient effect of a Medium is transmitted via hydraulic piston between the chassis and a vehicle body.

In air suspensions so-called rolling bellows are usually used, which roll over a plunger. The spring effect is generated by the compressed medium in the working space, which is usually air or gas.

In contrast, the deformation of the bellows structure in a bellows spring itself generates the spring force, without the need for an additional medium must be used. The pleats of the bellows of a bellows spring change from an outer diameter to a smaller inner diameter. Therefore, a bellows spring has undercut portions, which cause problems in a production. The core for component manufacturing can be implemented either as a lost core or in the form of a silicone tube or vacuum bag as an elastic core. This is not economically feasible, especially in mass production and at the same time low durability of elastic cores and high costs due to lost cores by means of conventional procedures.

With the rolling method according to the invention, such a bellows spring is preferably made of a thermoplastic, reinforced with axial fibers tube, which was prepared for example by means of a pultrusion or winding process, in a simple manner.

A torsion tube of a torsion beam axle has inter alia a defined torsional rigidity in order to be able to represent the function of a stabilizer. In addition, a torsion tube is usually designed to provide different flexural stiffnesses about the longitudinal axis in different planes. Furthermore, a shear center outside of the profile can be displayed via such a torsion tube in order to influence a rolling center of a torsion beam axis.

Since the requirements for a torsion beam axis in conjunction with a shape optimization results in different cross-sectional profiles in a front view (yz plane) and in a plan view (xy plane), the cross sections are characterized by constrictions and bulges, which also not by a solid core tool are shapeable.

During the manufacture of a torsion tube, for example, a dry, textile preform or a so-called prepreg can be applied to a solid core, for example by braiding, whose diameter is smaller than the smallest inner diameter of the torsion tube. During the rotation of the preform or the deposited prepregs, this dissolves or detach from the inner core and attach to the outer shape of the tool. Subsequently, the core can be removed from the mold. The divisible outer tool is opened after the curing of the torsion tube and the finished component can be removed.

In the context of the present invention, an axial undercut section is understood to mean a section with an undercut relative to the axis about which the fiber preform is rotated together with the tool at least during the production of the final shape of the fiber-plastic composite component in the tool.

Depending on the respective application, the at least one fiber or the fibers combined to form at least one roving are impregnated with the curable fluid plastic before, during and / or after production of the fiber preform. This means that the fiber or the roving is impregnated during a first process step and can be guided, for example, through a resin bath and then drawn through heated spinnerets in order to adhere the resin or the curable fluid plastic to the roving.

In advantageous variants of the method according to the invention, the at least one fiber or the at least one roving is impregnated by spraying and / or spraying the fluid curable plastic, immersing in a bath of curable fluid plastic and / or injecting the curable fluid plastic with this.

Instead of pre-impregnated rovings, dry rovings can also be wound onto the preforming tool, for example retaining rings, and finally sprayed or infiltrated with resin. In this case, it is possible to spray the fiber preform from the inside and outside and in this case preferably to oscillate the holding devices of the preform in an oscillating manner in order to facilitate the impregnation. Furthermore, rollers or ring segments with diameter that deviate from the preform or the fiber preform can walk inside and outside the roving strands in order to evenly distribute the impregnation in the fiber preform. In this case, provision may be made for the preform to be heated and, under certain circumstances, subsequently cooled again in order to achieve a better gelation of the resin or of the curable fluid plastic.

If the fiber preform is rotated at least about a defined axis of rotation during the impregnation of the at least one fiber with the curable fluid plastic, undesired penetration of the plastic into the inner cylindrical cavity delimited by the fiber preform is easily avoided and a desired uniform wetting or impregnation is desired the fiber preform achieved with little effort.

A further uniform distribution of the curable fluid plastic in the fiber preform ensuring variant of the method according to the invention provides that the impregnated with the curable fluid plastic and present in the final form of the fiber-plastic composite component during the curing of the plastic at least one defined axis of rotation is rotated.

The fiber preform is introduced in another easily feasible variant of the method according to the invention in the opened tool and then the tool is closed.

If the tool is rotated with the fiber preform at a predetermined minimum speed, a good deposition of the fiber preform is ensured on the tool surface without further action.

The axis of rotation of the tool and the fiber preform can be changed dynamically to create a tumbling motion. The direction of rotation can be changed. The axis of rotation can be selected, for example, perpendicular to the axis of the component.

In a further advantageous variant of the method according to the invention, the fiber preform is axially mechanically relieved during rotation in order to relax the fibers and deposit the fiber preform on the tool surface.

If the fiber preform is twisted during deposition, the fiber preform can be produced with a desired orientation of the fibers.

The curing of the plastic can be assisted by means of microwave radiation to shorten manufacturing times of the fiber-plastic composite component.

For producing the fiber preform, fibers can be processed in a winding process, wherein the fibers can be present as roving. During winding, the fibers can be moved axially relative to each other about a winding spool. Furthermore, the fibers and the reel spool can be moved oscillating relative to one another during winding. The fibers may be wound as a hank, helical and / or orthocyclic. During winding, the reel spool can be moved relative to the fibers. The fibers can also be moved relative to the reel spool. Furthermore, the fibers can be wound in a linear winding process and / or a flyer winding process. In order to tension the wound fibers, the fiber preform may be mechanically stressed axially during winding. During winding or after winding, the fiber preform may be subjected to a stabilizing agent for mechanical stabilization, wherein the stabilizing agent may act chemically or physically. The stabilizer may be a thermoplastic film, yarn, binder powder or sprayable binder. Furthermore, the stabilizing agent may also be water, which freezes on a cooled fiber preform with appropriate process control.

For example, to aid the application of the fiber preform during rotation of the impregnated fiber preform and the tool on the tool surface, it is possible to draw a membrane into the fiber preform. Then, in contrast to an open manufacturing process, an inflatable tube is drawn into the tool, via which the impregnated fiber preform can be additionally pressurized from the inside. The fiber preform may have an outer diameter and a clear inner diameter. Further, when drawn, the membrane may have an outside diameter equal to or smaller than the inside diameter of the fiber preform. In addition, the tool may have a clear inner diameter, and the fiber preform may be designed to be inserted with an outer diameter equal to or smaller than the clear inner diameter of the tool.

A molding space defined between the membrane and the tool surface may be sealed prior to expanding the membrane and evacuating the mold space. It is possible to expand the membrane by means of a tempered pressure medium and the deposition of the fiber preform on the tool surface on the then acting on the fiber preform contact pressure on the tool surface in addition to the centrifugal forces acting on the fiber preform, resulting from the rotation of the tool and the fiber preform to speed up and assist if necessary.

The pressure medium can be heated and be a fluid. There is a possibility that the Pressure medium is air-, water- or oil-based. The membrane can also be expanded by the atmospheric pressure, wherein the mold space is evacuated by applying negative pressure.

In addition, the deposition of the fiber preform in the mold can be promoted by a plane Luftsog. The air suction can be generated for example by radial bores and negative pressure outside the mold.

To generate the negative pressure, for example, an axial or radial turbine, such as a compressor, used.

As an alternative or in addition to the winding method, it is also possible to produce the fiber preform via an annular feed of a plurality of fibers, preferably in the form of rovings, from a yarn gate. For this purpose, a holding, tensioning and extraction device can be used.

If the fibers are distributed over a cylinder surface by a die with annular recesses and then pulled off the thread gate, the fiber preform can be produced inexpensively and within short process times with little effort. It can be provided that instead of a single roving or instead of several bundled rovings a plurality of rovings are distributed through a die with annularly arranged holes / nozzles on the cylinder surface and then pulled off axially.

A thread gate in this case represents a device which stores the rovings, for example in the form of coils, which holds the rovings on tension and supplies them to a die without the rovings blocking each other.

In a further advantageous variant of the method according to the invention, the rovings are impregnated before or after the die with the curable fluid plastic.

The holding device can, for example, have an inner ring and an outer ring, which makes it possible either by divisibility of the outer ring or conical clamping surfaces to clamp all the rovings fed from the die over the closed circumference.

The preparation of the fiber preform is particularly simple when the rovings are separated from the thread gate by cutting off the cylindrical preform of the cylindrical preform of the fiber preform.

For this purpose, for example, a cutting device can be provided which separates the rovings after the clamping of the cylindrical preform of the take-off device. In addition, the cutting process can also be carried out by the holding device itself by edges are formed, for example, sharp-edged at the end of the conical clamping surface. The cutting can also be assisted by turning the preform holding device, wherein the holding device can be connected, for example, with manipulators designed as robots, which perform the required movements and twists.

The fiber-plastic composite component to be produced in each case can be formed by an open method or additionally by means of an inflatable tube, which can be in the form of a film tube, a thermoplastic blow mold, a silicone tube or the like, in order to close off the inside of the fiber preform during the curing , getting produced.

An apparatus for carrying out the method according to the invention comprises, for example, a rotatable winding device with a rotation axis, a first ring arranged concentrically to the rotation axis, a second ring arranged concentrically to the rotation axis and axially spaced from the first ring and a holding device arranged between the rings and a rotatable tool a rotation axis and a radially inner tool surface for defining a mold space.

The device may have at least one rotary drive. The device may have a rotary drive for the winding device. The device may have a rotary drive for the tool. The first ring and the second ring can be arranged mirror-symmetrically to each other. The first ring and the second ring may be fixable to each other at a predetermined distance. The holding device can serve as a winding spool. The holding device may have a cylindrical shape. The holding device can be wound with fibers. The holding device can be extended and / or shortened in the axial direction. The tool can be opened and / or closed. The tool can be divisible along the axis of rotation. The tool can have two mold halves. The tool can have several tool segments.

The first ring and the second ring may be axially displaceable relative to one another. For displacing the first ring and / or the second ring, the device may comprise at least one elastic element and / or at least one actuator. The cavity can be made using the first ring and the second ring to be tightly closed. The mold space can be tightly closed by axial displacement of the first ring and / or the second ring. The first ring and / or the second ring may have at least one channel for evacuating the mold space and / or for injecting a plastic. The device may comprise an evacuation device. The device may comprise a plastic injection device.

The at least approximately rotationally symmetrical fiber-plastic composite component with at least one axial undercut section may have an axis of rotation. The component may have a longitudinal axis. The at least one axial undercut section may be formed by different diameters of the component along the rotational or longitudinal axis. The at least one axial undercut section can make it difficult or prevent removal of the component from a closed tool in the axial direction. An axial direction may be an extension direction of the rotational or longitudinal axis. The component may have a plurality of axial undercut portions. The component may have a plurality of axial undercut portions, which may be arranged in succession in the axial direction. The component may have a wave-like varying diameter. The component may have a bellows-like shape. The component may have spring properties in the axial direction. The component may have connection sections at its axial ends. The component may be a bellows spring. The bellows spring can also act independently of a filling medium itself as a spring. The component may be a bellows spring for a chassis of a vehicle. The vehicle may be a motor vehicle. The vehicle can be a car. The vehicle can be a truck. The vehicle can be a commercial vehicle. The vehicle may be a rail vehicle.

The component may comprise endless fibers. The component may comprise inorganic fibers. The component may comprise glass fibers and / or ceramic fibers. The component may comprise metallic fibers. The component may comprise steel fibers. The component may comprise organic fibers. The component may comprise aramid fibers, carbon fibers, polyester fibers, nylon fibers, polyethylene fibers and / or Plexiglas fibers. The component may comprise natural fibers. The component may have a plastic matrix. The component may have a thermoplastic matrix. The component may comprise polyetheretherketone (PEEK), polyphenylene sulphide (PPS), polysulphone (PSU), polyetherimide (PEI) and / or polytetrafluoroethene (PTFE). The component may have a thermosetting matrix. The component may be epoxy resin (EP), unsaturated polyester resin (UP), vinyl ester resin (VE), phenol-formaldehyde resin (PF), diallyl phthalate resin (DAP), methacrylate resin (MMA), polyurethane (PUR) and / or amino resin, such as melamine resin (MF / MP) or urea resin (UF). The component may have an elastomeric matrix.

Summarized and shown in other words, thus resulting in the invention, inter alia, a manufacturing method for a bellows spring or a torsion tube. The bellows spring or the torsion tube can be a fiber composite component which can be used, for example, in a wheel carrier module. Furthermore, for the production of a special form of the Vacuum Assisted Resin Injection (VARI) method can be used, in which a textile preform is produced, which can be impregnated before applying the fiber preform on a tool surface with a curable fluid plastic or a resin and during a Rotation of the fiber preform and the tool under preferably simultaneous pressurization and tempering is curable.

With the invention, a production with reduced effort is possible. A cheap mass production is possible. A tool-side effort is reduced. A high component quality is achieved. The requirements of high-quality components are combined with simultaneously low production costs. Also, thermosetting resin systems are processable. A laying down of fibers is facilitated. Fibers can be oriented in a targeted manner. During curing, a predetermined temperature profile can be displayed. Stability of a fiber preform can be increased. Curing can be accelerated.

By "may" in particular optional features of the invention are referred to. Accordingly, there is an embodiment of the invention each having the respective feature or features.

Both the features specified in the claims and the features specified in the subsequent embodiments of the subject invention are each suitable alone or in any combination with each other to further develop the subject invention.

Further advantages and advantageous embodiments of the subject invention will become apparent from the claims and the embodiments described in principle below with reference to the drawings, wherein the same reference numerals are used in the description of the various embodiments in favor of clarity for construction and functionally identical components.

It shows:

1 a winding device having a first ring, a second ring and a holding device;

2 a winding device with a tool having a radial inner surface;

3 a schematic representation of another device for producing a fiber-plastic composite component with a thread-gate with impregnating and annular die and a trigger device;

3a a trigger device of the device according to 3 ;

3b an impregnating device according to the device 3 ;

4 a holding device for removing rovings and mounting a cylindrical preform; and

5 a schematic representation of a conventional twist beam axle with a torsion element;

6 a highly schematic longitudinal sectional view of the torsion element of the torsion beam axle according to 5 in a front or rear view; and

7 a 6 corresponding representation of the torsion element in a plan view.

1 shows a detail of a winding device 1 with a first ring 2 , a second ring 3 and a holding device 4 , The winding device 1 is part of a device for producing a rotationally symmetrical bellows spring made of a carbon fiber-resin composite. The winding device 1 serves to produce a fiber preform, which is prepared in the manner described in more detail below. This is the winding device 1 around a rotation axis 5 rotatable.

The first ring 2 and the second ring 3 are coaxial with each other and axially spaced from each other. Furthermore, the rings have 2 . 3 each have a cylindrical inner surface and a stepped outer surface. In addition, the rings 2 . 3 executed with an L-like cross-sectional area and arranged mirror-symmetrically to each other. The holding device 4 lies between the rings 2 . 3 and is on outer surfaces of the rings 2 . 3 tethered. The cylinder-like shape holding device 4 can be extended and / or shortened in the axial direction. The Rings 2 . 3 and the holding device 4 form a so-called winding spindle.

To produce a fiber preform, first a roving 6 attached with one end to the winding spindle. The roving 6 lies here as a support-free Rovingpackung 7 with internal deduction in front. Subsequently, the winding spindle according to arrow a is about the axis of rotation 5 turned. This is the roving 6 the roving pack 7 removed and on the holding device 4 wound. To achieve a given winding, the winding spindle and the Rovingpackung 7 moved in the axial direction relative to each other. In addition, the winding spindle according to arrow b is a to the axis of rotation 5 angularly arranged axis pivoted. To stretch the wrapped roving, the rings become 2 . 3 according to arrows c, e acted upon in the axial direction with a clamping force. To tighten the rovings is the holding device 4 for example, by an elastic element or an actuator in the axial direction apart.

The fiber preform made in accordance with the above description is used together with the winding device 1 in an in 2 shown tool 9 with a radially inner surface 10 brought in. The tool 9 has a cylindrical shape and can be opened and closed for introducing the fiber preform. This is the tool 9 along the axis of rotation 5 divisible trained.

The inner surface 10 has a wave-like shape and the tool 9 is with inner ribs 11 executed. The inner ribs 11 each run in a circle on the inner surface 10 of the tool 9 and are axially spaced apart, with the spacing between the inner ribs 11 in about an axial width of an inner fin 11 equivalent. In addition, the inner ribs have 11 radially inside each have a semicircular convex rounded cross-section. A reason between the inner ribs 11 is in turn each executed with a semicircular concave rounded cross-section. This is the tool 9 formed with a large inner diameter D and a small inner diameter d, wherein the small inner diameter d is also denominated as a clear diameter.

The one by winding up the roving 6 on the holding device 4 initially produced fiber preform has a smaller outer diameter than the small inner diameter d of the tool 9 on. After the introduction of the fiber preform, the tool 9 and the fiber preform together with the winding spindle according to arrow f about the axis of rotation 5 turned. The Rings 2 . 3 are shifted according to arrows g, h in the axial direction, so that the wound roving 6 is relaxed. Under the influence of centrifugal force, the fiber preform becomes on the inner surface 10 stored. To drop off to support, the rings become 2 . 3 oscillating against each other.

Depending on the respective application, either a pre-impregnated roving or a plurality of pre-impregnated rovings are wound on the winding spindle and into the tool for the production of the fiber preform in the manner described above 9 introduced and the deposition of the fiber preform on the inner surface 10 of the tool 9 further supported by the higher weight of the fiber preform under the influence of centrifugal force. Deviating from or in addition to this, it is also possible to use the winding device 1 first to prepare a dry fiber preform, prior to insertion into the tool 9 sprayed or splashed with a thermosetting fluid resin or dipped in a resin bath to the fiber preform prior to application to the inner surface 10 of the tool 9 to impregnate to the extent required. In particular, during immersion in a resin bath, it is advantageous if the fiber preform is rotated during the impregnation process, since then the entire fiber preform is charged with the resin without having to immerse it completely in the resin bath. Thus, a uniform distribution of the resin in the fiber preform or a uniform impregnation of the fiber preform is achieved in a simple manner.

The cylindrically stretched prepreg shape or the fiber preform has a smaller or only slightly larger outer diameter than a smallest outer diameter of a bellows spring to be produced or as a smallest diameter of the tool 9 on. In addition, the axial length of the fiber preform is chosen so that the axial settlement of the bellows spring or the fiber-plastic composite component to be produced is covered. The cylindrically stretched prepreg mold or the fiber preform is inserted into the mold 9 , which forms the outer contour of the bellows spring or the fiber-plastic composite component to be produced, transferred and advantageously aligned therein coaxially. In addition to the lying at least in the region of an axis part plane of the tool 9 It is also possible to produce the tool from several segments that can be moved apart radially to bring the fiber preform to the desired extent in the tool can.

The fully designed with the prepreg or the impregnated fiber preform shape of the tool 9 is transferred in rotation to release the equipment to cover another mold with impregnated rovings in the next cycle.

Subsequently, the impregnated fiber preform is heated by heating the tool 9 , Hardened by heating in an oven or by applying a hot medium or by applying a high-energy radiation, such as microwave radiation, infrared radiation or the like, to the extent desired, during the curing process, the impregnated fiber preform together with the tool 9 is rotated further. As a result of the rotation during the curing process, the resin or curable fluid plastic is pressed further into the fiber structure of the rovings and, in addition, a certain pressure is exerted on the fiber preform.

3 shows a schematic representation of a device 13 , via which it is likewise possible to produce a fiber preform which is incorporated into the in 2 illustrated tool 9 can be inserted and further processed. About the device 13 be several rovings 61 to 68 annularly distributed and cylindrically stretched. For this purpose, an annular feed from a rovings 61 to 68 having thread gate 14 , The rovings 61 to 68 be before inserting into an annular withdrawal device 15 , in the 3a from an in 3 is shown by the arrow III a closer marked view, by an impregnating device 16 passed and there with the curable fluid plastic 17 impregnated. The impregnation device 16 is in turn in 3b reproduced with great simplicity and with several rollers 18 to 22 trained over which the rovings 61 to 68 in the in 3b manner illustrated by the impregnation 16 be guided.

In the area of the extraction device 15 become the rovings 61 to 68 through a die 23 with annularly arranged holes or nozzles 24 over a cylinder surface 25 distributed and then withdrawn axially. The thread gate 14 is part of the device 13 in which area the rovings 61 to 68 for example, in the form of coils are stored and in their area the rovings 61 to 68 held on tension and from there starting the die 23 be fed without the rovings 61 to 68 block each other.

In 3 is the impregnation device 16 in front of the matrix 23 in which area the rovings 61 to 68 arranged in a ring. Alternatively, there is also the option of the rovings 61 to 68 after the matrix 23 to obtain an impregnated fiber preform.

After the withdrawal device 15 become the rovings 61 to 68 in an in 4 simplified holding device shown 26 inserted, each axially spaced inner rings 27 . 28 and also axially spaced outer rings 29 . 30 having. The inner rings 27 . 28 are each with conical outer surfaces 27A . 28A executed while the outer rings 29 . 30 in each case corresponding conical inner surfaces 29A . 30A exhibit. To insert on the cylinder surface 25 arranged rovings 61 to 68 in the holding device 26 are the inner ring 27 and the outer ring 29 as well as the inner ring 28 and the outer ring 30 the holding device 26 in the in 4 shown manner spaced from each other. The rovings 61 to 68 are thus in the area between the conical outer surface 27A and the conical inner surface 29A as well as the conical outer surface 28A and the conical inner surface 30A the inner rings 27 . 28 and the outer rings 29 and 30 feasible. In the inserted state of the rovings 61 to 68 become the inner rings 27 . 28 axially against the outer rings 29 . 30 pressed and the rovings 61 to 68 between the inner and outer rings 27 to 30 clamped. Subsequently, the still with the thread gate 14 related rovings 61 to 68 via a cutting device 31 in the area between the inner ring 27 or the outer ring 29 and the matrix 23 after clamping the cylindrical preform of the trigger device 15 separated. There is the possibility of the cutting process by the separate cutting device 31 or one in the holding device 26 to realize integrated cutting device. In the latter embodiment of the holding device 26 For example, there is the possibility of the trigger device 15 facing edges of the inner ring 27 and / or the outer ring 29 sharp edged form and in this area of the holding device 26 the rovings 61 to 68 from the trigger device 15 to separate. In this case, the cutting operation by turning the holding device 26 get supported.

To the above-described movements in the region of the holding device 26 to realize, is the holding device 26 executed with manipulators, not shown, such as robotic devices or the like.

Both after the preparation of the preform according to the description 1 as well as the description too 3 and 4 there is a possibility that in the rings 2 . 3 or in the inner rings 27 . 28 a tubular airtight membrane 8th is retracted, which has a diameter corresponding to an inner diameter of the rings 2 . 3 or the inner rings 27 . 28 equivalent. After making the fiber preform, the fiber preform becomes the tool 9 introduced and then in the zu 2 described way further processed.

In addition, the machining of the fiber preform in the tool 9 while depositing the fibers in the tool 9 be favored by a plane Luftsog, by radial bores and negative pressure outside of the tool 9 is produced. The negative pressure is generated by an axial or radial turbine, for example a compressor, in which the rotating tool 9 Outside turbine blades not shown in detail, which are operatively connected to a stationary housing. The housing may include further turbine blades and air from the tool 9 remove through the holes.

After placing the fiber preform on the inner surface 10 of the tool 9 become the rings 2 . 3 or the inner rings 27 and 28 together with the outer rings 29 . 30 displaced towards each other in the axial direction until they respectively on the tool 9 lie tightly and between the tool 9 , the rings 2 . 3 or the rings 27 to 30 and the membrane 8th a closed form space 12 is formed. The following is the shape space 12 evacuated and the membrane 8th while radially expanding, so that the fiber preform between the tool 9 and the membrane 8th is fixed largely air-free. To expand the membrane 8th becomes the shape space 12 with negative pressure and the membrane 8th from radially inside, for example, acted upon by a heated pressure medium.

Subsequently, the impregnated fiber preform in the tool 9 hardened. This is an internal pressure in the membrane 8th can be increased. Besides that is the tool 9 heated. In addition, a microwave irradiation can take place radially inward.

Subsequently, the finished fiber-plastic composite component or the bellows spring or a torsion tube of a torsion beam axle is removed from the mold and, for example, trimmed at the end, so that the rings 2 . 3 or the inner and outer rings 27 to 30 can be removed. Again, the entire system is automatically cleaned and ready for a new process.

In addition, it is also possible, in addition to a bellows spring, for example, a in. In addition to the above-described variants of the method 5 to 7 closer shown, as a torsion element 32 trained, fiber-plastic composite component of a 5 shown torsion beam axle 33 manufacture. The torsion beam axle 33 is next to the torsion element 32 with trailing arms 34A . 34B , Bushings 35A . 35B as well as lower and upper spring seat pressed parts 36A . 36B . 36C . 36D educated. In addition, the torsion beam axle includes 33 endplates 38A . 38B for connecting a wheel bearing.

About the torsion element or the torsion tube 32 is a defined torsional rigidity of Beam axle 33 provided in order to provide the function of a stabilizer. Furthermore, depending on the cross-sectional configuration of the torsion tube 32 , which are exemplary in 6 and 7 is shown, different bending stiffness about the longitudinal axis depending on the level representable. In addition, with appropriate design of the torsion tube 32 also a shear center outside the profile laying around the rolling center of the torsion beam axle 33 to influence.

From the above requirements for the torsion 32 and a shape optimization to be carried out for this, different cross-sectional profiles result in the longitudinal direction of the torsion element 32 in the in 6 shown yz-plane (front view) and in the in 7 shown xy-plane (view from above). The cross sections according to 6 and 7 Each is characterized by tapers and bulges that can not be formed by a solid core tool.

The torsion element 32 is manufacturable according to one of the above-described variants of the method. In addition, however, it is also possible to apply the dry textile preform or the prepreg or the fiber preform to a solid core, for example by braiding, which is smaller in diameter than the smallest diameter of the torsion tube 32 is. During the rotation of the preform or the deposited prepreg, the fiber preform detaches from the solid core and settles on the inner surface 10 of the tool 9 at. Then the core is out of the tool 9 removable. The divisible tool 9 is opened after curing of the impregnated fiber preform and the finished fiber-plastic composite component can be removed from the tool 9 be removed.

LIST OF REFERENCE NUMBERS

1

winding device

2

first ring

3

second ring

4

holder

5

axis of rotation

6

roving

7

roving package

8th

membrane

9

Tool

10

surface

11

internal rib

12

cavity

13

contraption

14

creels

15

off device

16

impregnating

17

plastic

18 to 22

roller

23

die

24

Nozzle, hole

25

cylinder surface

26

holder

27

inner ring

27A

conical outer surface

28

inner ring

28A

conical outer surface

29

outer ring

29A

conical inner surface

30

outer ring

30A

conical inner surface

31

cutter

32

torsion

33

Beam axle

34A, 34B

Trailing arm

35A, 35B

bearing bush

36A, 36B

lower spring seat pressed part

36C, 36D

upper spring seat pressed part

38A, 38B

cold forged end plates

61 to 68

roving

d, D

diameter

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102013209143 [0002]

Claims (19)

Method for producing an at least approximately rotationally symmetrical fiber-plastic composite component ( 32 ) with at least one axial undercut section, wherein at least one fiber is produced from at least one approximately hollow cylindrical fiber preform, which in a tool ( 9 ) is transferred to the final form of the fiber-plastic composite component, wherein subsequently the with a curable fluid plastic ( 17 ), wherein the fiber preform is initially subjected to axial mechanical loading during its production for tensioning the at least one fiber and at least during the production of the final shape of the fiber-plastic composite component in the tool ( 9 ) together with the tool ( 9 ) and thereby mechanically relieved to relax the at least one fiber, characterized in that the at least one fiber of the fiber preform before the creation of the final shape of the fiber-plastic composite component in the tool ( 9 ) with the curable fluid plastic ( 17 ) is impregnated. A method according to claim 1, characterized in that the at least one fiber before, during and / or after the production of the fiber preform with the curable fluid plastic ( 17 ) is impregnated. A method according to claim 1 or 2, characterized in that the at least one fiber by spraying and / or spraying the fluid curable plastic ( 17 ), Immersion in a bath of curable fluid plastic ( 17 ) and / or injecting the curable fluid plastic ( 17 ) is impregnable with this. Method according to one of claims 1 to 3, characterized in that the fiber preform during the impregnation of the at least one fiber with the curable fluid plastic ( 17 ) at least about a defined axis of rotation ( 5 ) is rotated. Method according to one of claims 1 to 4, characterized in that the with the curable fluid plastic ( 17 ) impregnated fiber preform present in the final form of the fiber-plastic composite component during the curing of the plastic ( 17 ) at least about a defined axis of rotation ( 5 ) is rotated. Method according to one of claims 1 to 5, characterized in that the fiber preform in the opened tool ( 9 ) and the tool ( 9 ) is closed. Method according to one of claims 1 to 6, characterized in that the tool ( 9 ) is rotated with the fiber preform at a predetermined minimum speed. Method according to one of claims 1 to 7, characterized in that the fiber preform is axially mechanically relieved during rotation in order to relax the fibers and the fiber preform on the tool surface ( 10 ). A method according to claim 8, characterized in that the fiber preform is twisted during the depositing. Method according to one of claims 1 to 9, characterized in that the curing of the plastic ( 17 ) is supported by microwave radiation. Method according to one of claims 1 to 10, characterized in that for producing the fiber preform fibers are processed in a winding process. A method according to claim 11, characterized in that the fibers are wound as a trickle winding, helically and / or orthocyclically. A method according to claim 11 or 12, characterized in that the fibers are wound in a linear winding process and / or a flyer winding process. Method according to one of claims 11 to 13, characterized in that the fiber preform is axially mechanically loaded during winding to tension the wound fibers. Method according to one of claims 11 to 14, characterized in that the fiber preform during winding or after winding is applied for mechanical stabilization with a stabilizing agent. Method according to one of claims 1 to 15, characterized in that the fiber preform via an annular supply of several preferably in the form of rovings ( 61 to 68 ) present fibers from a thread gate ( 14 ) will be produced. A method according to claim 16, characterized in that the fibers are passed through a die ( 23 ) with annularly arranged recesses ( 24 ) over a cylinder surface ( 25 ) and then from the thread gate ( 14 ) subtracted from. Method according to claim 17, characterized in that the rovings ( 61 to 68 ) before or after the die ( 23 ) with the curable fluid plastic ( 17 ) are impregnated. Method according to claim 17 or 18, characterized in that the rovings ( 61 to 68 ) after the cylindrical clamping of the cylindrical preform of the fiber preform of the thread gate ( 14 ) are separated by clipping.

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