DE102009051459B4 - Method for producing a hollow composite fiber composite part - Google Patents

Abstract

A method for producing a fiber composite part having a hollow profile, in which several fiber layers are wound over a one-part or multi-part core in a radial braiding process, then a curable compound, preferably synthetic resin, is injected and cured and, if necessary, the core is at least partially removed, with the fiber composite part at at least one reinforcing insert is integrated into at least one load-critical point, characterized in that the reinforcing insert is designed as a metallic reinforcing insert (14) and is held in position by at least one magnet (16) inserted into a reusable core (10).

Description

The invention relates to a method for producing a hollow profile having fiber composite part according to the preambles of claims 1 and 3.

A method for braiding a hard foam core with a braiding structure consisting of high-performance fibers with regions having a different number of layers (different wall thickness) is described, for example, in US Pat DE 102 59 593 A1 using a radial braiding machine combined with a linear feeder etc.

By the DE 103 28 045 A1 It is also known, when producing a foamed vehicle part, for example a vehicle interior trim, to hold a metallic insert part by means of a magnet in the foaming tool.

The DE 10 2007 057 198 A1 describes a method for producing a fiber composite hollow body in which so-called continuous reinforcing fibers are applied to a lost mold corresponding to the later cavity and fastened there before these reinforcing fibers are impregnated with a curable resin. In the fiber composite component functional parts of Faserprepregs, metal parts and / or plastic parts can be integrated, which should be such functional parts that do not serve for reinforcement, but are formed by sleeves for metallic fasteners, such as screws, welding flanges or hinges.

The object of the invention is to provide a method, which is suitable in particular for automatic production, for producing a particularly load-bearing fiber composite part.

This object is achieved with the features of the independent claims. Advantageous developments of the method specify the dependent claims.

According to claim 1, it is proposed according to the invention that at least one metallic reinforcing insert is integrated into the fiber composite part at at least one load-critical point. The metallic reinforcing insert is kept in production technology particularly favorable by at least one magnet inserted into the reusable core of, for example, PU foam in position. This makes it possible to position the reinforcing insert in a particularly simple manner before or during the wrapping of the core manually or automatically. The core can be removed after completion of the fiber composite part with the integrated magnet and optionally reused. The magnet may preferably be foamed in with the production of the core in these.

An improved stress distribution in the component is furthermore achieved by winding around the core with the integrated magnet at least one fiber layer, then positioning the at least one reinforcing insert by magnetic force and then further wrapping the component composite with at least one further fiber layer. This ensures a homogeneous and high-strength integration of the reinforcing insert in the fiber composite or in the fiber composite part. As fiber material, all suitable materials in question, that is metallic fibers as well as plastic fibers. Also composite materials and with respect to the material different fiber layers can be used.

In an alternative embodiment, it is proposed that, in the case of a multi-part core, at least one core section be used as reinforcing insert as a lost core section forming a reinforcement region on the finished component, which is preferably designed as a hollow profile, most preferably as a metallic hollow profile at least one reusable, formed for example of PU foam, further core section connects. Here, for example, formed as a solid material, but preferably as a hollow profile core portion thus at the same time forms a lost core, which remains in the fiber composite part and represents a particularly powerful reinforcement in the stress critical area.

Preferably, the at least two core sections can be connected to each other before wrapping by means of a plug connection, for example telescopically. This results in a particularly quick and precise assembly of the core of the fiber composite part, wherein the reusable core portion is easily removable.

Favorable stress distributions in the fiber composite part are also achieved if, at least in a transition region, the two core sections are designed with the same external configurations.

In the case of defined configurations of fiber composite parts, it is also proposed that between the two reusable core sections, a metallic core section and / or a lost core section made by hydroforming be used at a stress critical point.

For clamping the core of the fiber composite part in a Radialumflechtmaschine is the Further proposed that on the at least one reusable core preferably clamping elements are provided on both sides, on which or a robotic arm for positioning and for advancing movement of the core can attack. In this case, by means of at least one further robot arm, the at least one reinforcing insert can also be placed and positioned automatically on the core having the at least one magnet.

A particularly preferred fiber composite part is designed as an elongated hollow profile, with a central curvature section, which merges on the one hand in a pipe section having a smaller cross section and on the other hand in a base section having a larger cross section, wherein one or more reinforcing inserts are integrated into the curvature section. Thus, a stress-homogeneous transition of the component loads from the base part into the pipe part succeeds; For example, the fiber composite part may be the upper portion of an A pillar of the body of a convertible vehicle.

As reinforcements of the fiber composite part, for example, two half-shell-shaped reinforcing inserts may be used, which are held in the production by magnetic force to the core portions and positioned accordingly.

Alternatively, the reinforcing insert in the curved portion of the fiber composite part may be formed by a correspondingly adapted, metallic hollow profile, which may be manufactured particularly favorable in the hydroforming process.

Two embodiments of the invention are explained in more detail below with reference to the accompanying drawings. Show it:

1 the core of a provided with shell-shaped, metallic reinforcing inserts, indicated by dashed lines and having a hollow profile fiber composite part which can be produced in a Radialumflechtmaschine;

2 a section according to line II-II of 1 through the core in the area of reinforcement inserts;

3 to 5 in the same section plane as 2 the manufacturing process when wrapping the core with multiple fiber layers;

6 in highly abstracted form, the wrapping process of the fiber composite part in a radial braiding machine with robot control of the fiber feed and the insertion of the reinforcing inserts;

7 an alternative core for a fiber composite part with two reusable, for example, foamed core sections and a central, metallic core section, which also serves as a reinforcing insert; and

8th a section according to line VIII-VIII of 7 through one of the telescopic connections between the core sections.

The 1 shows a schematic representation of a core made of PU foam 10 for the production of a fiber composite part 12 , which is indicated in dashed lines.

The formed as a continuous hollow profile fiber composite part 12 In the embodiment, the upper portion of an A-pillar of a body of a convertible vehicle and is by wrapping the core 10 fabricated with, for example, carbon fibers in multiple fiber layers and then injecting, for example, a curable synthetic resin as a matrix.

In a bend section 12a with increasing from top to bottom cross section of the hollow profile are half-shell-shaped, metallic reinforcing inserts 14 (compare also 2 ) integrated. At the curvature section 12a on the one hand closes a tubular section 12b smaller cross-section and a base section 12c larger cross-section.

The core 10 is manufactured in a two-part core box (not shown), in which the shape of the core 10 is shown in the negative and is ejected with the PU foam. Before the introduction of the PU foam magnets are in the core box 16 (in the 1 indicated as circles) which adhere to the wall of the core box. These may optionally be integrated in the core box metallic Einlegererteile that hold the magnets first.

Furthermore, at the two front ends of the core 10 cone-like clamping elements 18 arranged, which are also set in the core box and in the manufacture of the core 10 be partially sprayed with.

With the injection and curing of the PU foam are the magnets 16 and the clamping elements 18 stuck to the core 10 connected. The core box can be opened and the core 10 with the magnets positioned on its surfaces 16 and the clamping elements 18 be removed.

In the production of the fiber composite part 12 (see 1 combined with 3 to 6 ) is in the radial braiding machine, not shown, a first fiber layer 20 wound up, the like out 4 also visible is the magnets 16 encloses.

Then the shell-shaped, made of, for example, steel sheet reinforcing inserts 14 placed in defined positioning and by the adhesive force of the core-side magnets 16 kept in position.

Thereafter, further, the wall thickness and the outer shape of the fiber composite part determining fiber layers 22 wound up ( 4 and 5 ) And finally in this fiber structure, a curing composition, preferably plastic resin, injected, with the resulting vacuum and cavities 24 (exaggerated) are eliminated and a homogeneous, high-strength fiber structure is formed.

The wrapping process of the fiber composite part 12 shows highly abstracted 6 , where the core 10 during the winding process via the clamping elements 18 which by the robots 26 . 28 through the radial braiding machine 33 be held.

robot 26 . 28 ensure a targeted feed movement of the core 10 while more robots 30 . 32 automates the reinforcements 14 Feed and hang up, then through the magnets 16 are held accordingly.

The 7 and 8th show an alternative embodiment for producing a fiber composite part 12 essentially analogous to 1 in which, however, a multi-part core 34 is used.

The core 34 consists of two reusable core sections made of, for example, PU foam 36 . 38 and a middle core section 40 from a preferably metallic, to the curvature section 12a (according to 1 ) matched hollow profile together. As the 7 In this case, the transition areas from one core section to the other can have the same external configuration.

The core section made of, for example, thin-walled steel sheet in the preferably hydroforming process 40 is with the foamed core sections 36 . 38 telescopically connected or on cross-section reduced projections 36a . 38a the core sections 36 . 38 attached.

Then the core becomes 34 ( 8th ) substantially as described above in a radial wrapping machine with inner and outer fiber layers 20 . 22 wrapped, each more or less continuously on the core 34 wound and injected by injecting a curable composition, for example of synthetic resin, and to a uniform fiber structure of the fiber composite part 12 get connected.

In the 6 represented robot 30 . 32 for inserting the reinforcing inserts can by directly serving as a reinforcing insert core section 40 eliminated in the fiber structure 20 . 22 is firmly integrated.

After completion of the fiber composite part 12 can the reusable core sections 36 and 38 be removed, so that a continuous consisting of a hollow profile fiber composite part 12 high component strength is created.

Claims (8)

A process for producing a fiber composite part having a hollow profile, in which several fiber layers are wound via a mono- or multi-part core in a radial braiding process, then a hardenable mass, preferably synthetic resin, injected and cured and optionally the core is at least partially removed, in the fiber composite part at least one stress-critical point at least one reinforcing insert is integrated, characterized in that the reinforcing insert as a metallic reinforcing insert ( 14 ) and by at least one into a reusable core ( 10 ) magnets ( 16 ) is held in position. Method according to claim 1, characterized in that around the core ( 10 ) with the at least one integrated magnet ( 16 ) at least one fiber layer ( 20 ), then the at least one reinforcing insert ( 14 ) and then the component composite is wrapped further. A process for producing a fiber composite part in which a plurality of fiber layers are wound over a multi-part core in a radial braiding process, then a hardenable mass, preferably synthetic resin, injected and cured, wherein at least one reinforcing insert is integrated into the fiber composite part at least one stress critical point, characterized that at least one core section ( 40 ) is used as a lost, on the finished component a reinforcing region forming core portion as a reinforcing insert to which at least one reusable further core section ( 36 . 38 ), which is removed from the finished component. A method according to claim 3, characterized in that the reinforcing insert forming core portion is formed by a hollow profile, most preferably by a metallic hollow profile. Method according to claim 3 or 4, characterized in that the at least one reusable core section ( 36 . 38 ) is formed of PU foam. Method according to one of claims 3 to 5, characterized in that the at least two core sections ( 36 . 38 . 40 ) are detachably connected together before wrapping by means of a plug connection. Method according to one of claims 3 to 6, characterized in that the adjoining core sections ( 36 . 38 . 40 ) are executed at least in a transition region with the same external configurations. Method according to one of claims 3 to 7, characterized in that between two reusable core sections ( 36 . 38 ) a produced in hydroforming process, preferably metallic core portion ( 40 ) at a stress critical location ( 12a ) is used.

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