DE102024110008A1 - Press tool device for producing a longitudinal component from a fiber composite material and method - Google Patents

Abstract

Pressing tool device for producing a longitudinal component from a fiber composite material or for producing a preform for such a component, wherein the longitudinal component is in particular a rod or a tube, comprising a receptacle (18) for a fiber device (20), wherein the receptacle (18) is assigned a longitudinal axis (16), at least three outer mold segments (24), each having an inner side (26) facing the receptacle (18), wherein each outer mold segment (24) is assigned a movement axis (30) which is oriented transversely to the longitudinal axis (16) of the receptacle (18), wherein the movement axes (30) of the outer mold segments (24) are aligned with a center (32), and wherein adjacent outer mold segments (24) are toothed with one another, and an infeed device (64) by means of which at least one outer mold segment (24) can be driven and displaced along its movement axis (30) for a pressing process on the fiber device (20).

Description

The invention relates to a pressing tool device for producing a longitudinal component from a fiber composite material or for producing a preform for such a component, wherein the longitudinal component is in particular a rod or a tube.

The invention further relates to a method for producing a longitudinal component from a fiber composite material or a precursor for such a longitudinal component.

The DD 51 423 A discloses a method and a device for producing hard fabric pipes, in which a fabric web impregnated with synthetic resin and dried is pre-compressed after passing through a heating section in a two-roll press, then, after further heating in a heating section with a three-roll system under high pressure, is rolled up into a coil and severed, then the coils are pressed into a two-jaw mold with only a slight reduction in volume and cured.

The EP 0 415 207 B1 discloses a method for producing a hollow body made of fiber-reinforced thermoplastic resin comprising disposing a prepreg containing a thermoplastic resin and reinforcing fiber therein between a thermally expandable core made of polytetrafluoroethylene and an outer mold outside this core, applying pressure to this prepreg by heating the prepreg and the core to cause expansion of the core, and cooling the core and the prepreg.

The DE 10 2012 106 117 A1 discloses a method for producing a cardan shaft from a fiber-plastic composite material.

The CN 207806629 U discloses a bimetallic composite tube material.

The invention is based on the object of providing a pressing tool device of the type mentioned above, by means of which longitudinal objects with a defined fiber direction can be produced.

This object is achieved according to the invention in the pressing tool device mentioned at the outset in that a receptacle for a fiber device is provided, wherein the receptacle is assigned a longitudinal axis, at least two outer mold segments, each with an inner side which faces the receptacle, are provided, wherein each outer mold segment is assigned a movement axis which is oriented transversely to the longitudinal axis of the receptacle, wherein the movement axes of the outer mold segments are aligned with a center, and wherein adjacent outer mold segments are toothed with one another, and an infeed device is provided by means of which at least one outer mold segment can be displaced in a driven manner in its movement axis for a pressing process on the fiber device.

By aligning the corresponding movement axes of the outer mold segments towards the center, a densification of the fiber arrangement can be achieved, while ensuring that the fiber flow is not interrupted.

In principle, each outer mold segment is movable along its movement axis in order to carry out the compaction. It is possible that if the movement axes of different outer mold segments coincide because they are exactly opposite each other, only one of these outer mold segments is movable and the other is fixed, although this still results in relative mobility along the movement axes. Furthermore, it is fundamentally possible for one outer mold segment of n outer mold segments to be fixed and the other (n - 1) outer mold segments to be movable. A corresponding axis of a fixed outer mold segment is aligned with the center and is also referred to here as the movement axis, since even during a pressing process, there is a relative movement of the fiber device to this fixed outer mold segment via movement of the other outer mold segments.

This effectively prevents fibers from slipping at a separation surface between the fiber device and the outer mold segments into a transition area between the outer mold segments, i.e., fibers from getting caught between the outer mold segments. Furthermore, wrinkles in the fiber device can be effectively prevented.

This allows the production of longitudinal components with, for example, a precise outer diameter. Pipes with a precise wall thickness can be manufactured. Longitudinal components with a uniform (and possibly high) fiber volume content can be produced. Fiber volume contents of up to 70 vol.% can be achieved.

For example, delamination-free C/C-SiC pipes with 3D fiber reinforcement can be produced on the basis of carbon fiber knits, whereby the pipes themselves have a high fiber volume content and a fiber knit as the starting material of the fiber device has a relatively low fiber volume content. The pressing tool device according to the invention enables a high degree of compaction to be achieved on a fiber device with a fiber knit.

The feed device can be designed in a structurally advantageous manner. For example, a feed device can be provided that has only one displacement axis, with a plurality of movement axes being provided by the plurality of outer mold segments.

It is particularly advantageous if adjacent outer mold segments are coupled to one another via a toothing and thereby engage with one another. The coupling can be contactless, or adjacent outer mold segments can be supported and/or guided against one another. A boundary line between the inner sides of adjacent outer mold segments has a change in direction and is, in particular, meandering. This allows a type of labyrinthine separation surface to be provided between the fiber device and the outer mold segments, which effectively prevents fibers from shifting into an area between adjacent outer mold segments.

Furthermore, an effective delivery for densification of the fiber device can be achieved.

Furthermore, it is advantageous if a first outer shape segment has first recesses and first teeth, wherein a first tooth lies between adjacent first recesses, and a second outer shape segment, which is adjacent to the first outer shape segment, has second recesses and second teeth, wherein the first teeth are immersed in respective second recesses and the second teeth are immersed in respective first recesses. In this way, an interlocking can be achieved between adjacent outer shape segments. This makes it possible to achieve effective guidance parallel to the axis of movement of the outer shape segments. Furthermore, a displacement of fibers of the fiber device into an area between adjacent outer shape segments of a parting surface can be effectively prevented. The teeth can, for example, have a rectangular shape or a sinusoidal shape or the like. The recesses are adapted accordingly.

• - die ersten Ausnehmungen verlaufen an dem ersten Außenformsegment von der Innenseite bis zu einer der Innenseite gegenüberliegenden Außenseite;
• - die zweiten Ausnehmungen verlaufen an dem zweiten Außenformsegment von der Innenseite bis zu einer der Innenseite gegenüberliegenden Außenseite.

In particular, it is advantageous if at least one of the following is provided:

• - the first recesses run on the first outer shape segment from the inner side to an outer side opposite the inner side;
• - the second recesses run on the second outer shape segment from the inside to an outside opposite the inside.

This effectively allows fiber penetration at a parting surface between adjacent outer mold segments. A labyrinthine transition between adjacent outer mold segments is achieved at the parting surface.

In particular, at least in one end position or in one end position range of the outer mold segments, a closed configuration of the inner sides of the outer mold segments with a closed lateral surface is provided, and in particular, adjacent outer mold segments are flush with one another. This makes it easy to achieve a continuous fiber orientation. A longitudinal object or a preform for a corresponding longitudinal object can be pressed with the desired shape.

In an advantageous embodiment, at least three outer mold segments are provided. As a result, each outer mold segment has a neighbor on both sides relative to a circumferential direction (which is a circumferential direction relative to the longitudinal axis). Each outer mold segment thus has two neighbors. Adjacent outer mold segments are connected to each other via a toothing. This results in effective compaction at the fiber device.

• - die mindestens eine Folie ist eine Metallfolie und insbesondere eine Stahlfolie;
• - die mindestens eine Folie weist eine Dicke im Bereich zwischen 0,1 mm und 0,3 mm auf und hat insbesondere eine Dicke von 0,2 mm;
• - die mindestens eine Folie überbrückt von der Fasereinrichtung aus gesehen einen Übergang an Innenseiten benachbarter Außenformsegmente.

It is particularly advantageous if at least one film is provided which is positioned between the fiber device and the inside of the outer mold segments, in particular with at least one of the following:

• - the at least one foil is a metal foil and in particular a steel foil;
• - the at least one film has a thickness in the range between 0.1 mm and 0.3 mm and in particular has a thickness of 0.2 mm;
• - the at least one film bridges a transition on the inside of adjacent outer mold segments, as seen from the fiber device.

The at least one film (additionally) prevents fibers from shifting into the transition area between adjacent outer mold segments. The provision of interlocking elements provides additional support for the film, effectively preventing the film from being squeezed into the transition area between adjacent outer mold segments. The film is particularly thin, with a thickness on the order of 0.2 mm. The film usually does not remain on the component or the preform.

In a structurally advantageous embodiment, the feed device comprises a pressing device with at least one pressing mold, wherein the at least one pressing mold has a recess in which one or more outer mold segments are positioned. The pressing device makes it easy to exert a pressing force, which can then be implemented as a pressing force of the outer mold segments with a direction of movement (direction of force) along the movement axis. By providing the recess, in which one or more outer mold segments are then at least partially positioned, a linear feed movement of two pressing molds, for example, can be easily implemented into movements along the different movement axes of the outer mold segments. In a specific embodiment, six outer mold segments are provided, which, when combined, have a hexagonal outer contour. Two pressing molds are provided, each having a respective recess adapted to the hexagonal outer contour. The two pressing molds can be moved towards one another, and a pressing movement of the outer mold segments with their respective movement axes towards the center can then be achieved.

In one embodiment, a guide device is provided for guiding the outer mold segments along their movement axes. The guide device is positioned outside the receptacle and, in particular, has at least one locating pin. This allows for targeted guidance and also positioning of the outer mold segments along the movement axes toward the center, enabling appropriate compaction of the fiber device in the receptacle.

In one embodiment, a core for the fiber device is positioned in the receptacle. This allows a hollow body, such as a tube, to be produced.

In one embodiment, the longitudinal object has a cylindrical shape with a circular cross-section, and the movement axes are aligned radially with respect to the circular cross-section, with the center lying on a cylinder axis, and wherein, in particular, at least six outer shape segments are provided. This allows a corresponding cylindrical object, such as a tube or a rod, to be produced, which has a precise outer diameter. A tube can achieve a precise inner diameter. It can be produced, in particular, with a uniform fiber volume content. A high fiber volume content can be achieved if required for a component.

It is also advantageous if the outer mold segments are continuous along the longitudinal axis of the holder, or if a plurality of outer mold segment discs are provided along a longitudinal axis of the holder. This allows for optimized adjustment, for example, of the diameter and/or length of the longitudinal object to be manufactured, depending on the application. The discs can be easily manufactured, for example, using waterjet cutting.

• - Kurzfasern, Fasergelege, Fasergewebe, gewickelte Faserpreform, geflochtene Faserpreform, gestickte Faserpreform, Faserschlauch;
• - ein Fasergestrick;
• - einen Kohlenstoff-Precursor und insbesondere ein Prepreg-Material.

It is advantageous if the fiber device includes at least one of the following:

• - short fibers, fiber scrims, fiber fabrics, wound fiber preforms, braided fiber preforms, embroidered fiber preforms, fiber tubes;
• - a fibre knit;
• - a carbon precursor and in particular a prepreg material.

For example, it is possible to produce a fiber composite tube with a precise and concentric inner and outer diameter and a constant wall thickness, which can also have a high fiber volume content and relatively high wall thicknesses. A longitudinal object such as a tube with a defined fiber flow can be produced. Delamination-free tubes such as C/C-SiC tubes with 3D fiber reinforcement can be produced. Carbon fiber knits can be used, which have a relatively low fiber volume content as the starting material. The pressing device according to the invention allows for strong densification of the fiber structure, so that the manufactured component then has a relatively high fiber volume content.

Depending on the component to be manufactured, the fiber arrangement comprises, for example, short fibers, a woven fiber fabric, or a knitted fiber fabric, although combinations are also possible. Short fibers are understood to mean, in particular, fibers with a length of less than 40 mm. In this sense, a woven fiber fabric, a knitted fiber fabric, or even a knitted fiber fabric comprises continuous fibers. A woven fiber fabric, for example, has a 2D orientation of fibers, while a knitted fiber fabric has a 3D orientation.

By using prepreg material, the carbon precursor is already contained in the fiber device. It can also be provided that a fiber device without carbon precursor is used on the pressing device according to the invention. is pressed and then resin infiltration with curing of the resin takes place on the pressing device.

The inventive solution makes it possible to use fiber knits with a 3D fiber orientation. This significantly reduces the risk of delamination, for example, during pyrolysis (after production of a fiber-reinforced preform).

According to the invention, a method of the type mentioned at the outset is provided, in which a fiber device is positioned in a receptacle and a plurality of outer circumferential segments, each with a movement axis, are provided, and in order to compress the fiber device, at least one outer mold segment is advanced with a movement axis transverse to a longitudinal axis of the receptacle relative to the fiber device, wherein the movement axes of the outer mold segments meet in a center, and wherein at least two mutually toothed outer mold segments are provided.

The method according to the invention has the advantages already explained in connection with the pressing tool device according to the invention.

In principle, during the advance of the outer mold segments, each outer mold segment is moved along its movement axis (with all movement axes converging at a center). For example, it is also possible for one outer mold segment to be stationary and all other outer mold segments to move along their respective movement axes. However, a movement axis can still be assigned to the stationary outer mold segment, since there is a relative movement of the other outer mold segments to this stationary outer mold segment, or there is a relative movement of the fiber device to this outer mold segment during pressing.

In particular, the method according to the invention can be carried out on the device according to the invention or the device according to the invention can be operated with the method according to the invention.

The process according to the invention provides a densified structure which, after curing a carbon precursor, becomes a fiber-reinforced preform. There may be applications in which this preform then becomes the final component.

In one embodiment, the fiber-reinforced preform is subjected to pyrolysis. This results in a CFRP component or a CFRP body, which is a fiber-reinforced carbon body (and in particular an open-pore carbon body). The fiber reinforcement can consist of carbon fibers or other fibers, for example.

The fiber-reinforced carbon body can, for example, be subjected to a carbide-forming process to produce, for example, a C/C-SiC component comprising a carbide phase (SiC), a carbon phase and a carbon fiber reinforcement.

Advantages of the method according to the invention have already been explained in connection with the pressing tool device according to the invention.

In particular, the center where the movement axes meet is surrounded by the fiber device. In one embodiment of a tube, the center is not in the material of the fiber device and is surrounded by the fiber device. In one embodiment of a rod, the center can also be in the material of the fiber device.

It is particularly advantageous if adjacent outer mold segments are supported and/or guided against each other via a toothing. This results in a defined infeed. Furthermore, a labyrinthine boundary line can be achieved at a transition between adjacent outer mold segments at a parting surface to the fiber device. This effectively prevents fibers from shifting into the transition area between adjacent outer mold segments.

Furthermore, to prevent fibers from shifting into the transition between adjacent outer mold segments, it is advantageous to position at least one foil, in particular a metal foil, between an inner side of the outer mold segments and the fiber device. This is particularly advantageous in combination with a toothing, which provides additional support for the foil, effectively preventing the foil from being squeezed into the transition area between adjacent outer mold segments. This, in turn, effectively prevents fibers from shifting at the parting surface into the transition between adjacent outer mold segments.

• - Kurzfasern, Fasergelege, Fasergewebe, gewickelte Faserpreform, geflochtene Faserpreform, gestickte Faserpreform, Faserschlauch;
• - ein Fasergestrick;
• - einen Kohlenstoff-Precursor und insbesondere ein Prepreg-Material.

It is advantageous if the fiber device includes at least one of the following:

• - short fibers, fiber scrims, fiber fabrics, wound fiber preforms, braided fiber preforms, embroidered fiber preforms, fiber tubes;
• - a fibre knit;
• - a carbon precursor and in particular a prepreg material.

The use of knitted fiber fabrics or short fibers makes it possible to create a 3D fiber orientation. This effectively prevents delamination during matrix shrinkage during pyrolysis, for example in thick-walled pipes. In principle, the volume fiber content of knitted fibers in the dry preform is relatively low. The process according to the invention makes it possible to achieve a high level of compaction, so that a relatively large wall thickness, for example in a pipe, can be achieved even when using short fibers and/or knitted fibers (with a 3D fiber orientation). The process according to the invention therefore makes it possible to use a fiber device with short fibers and/or knitted fibers, and to produce a relatively thick-walled pipe, whereby the risk of delamination is greatly reduced, particularly during pyrolysis. This also makes it possible to produce threads with a high load-bearing capacity on a pipe, rod, or the like, for example.

By providing a carbon precursor in the fiber assembly, a corresponding CFRP preform can be produced. This preform is produced by compacting the fiber assembly and curing the carbon precursor (especially a resin). The carbon precursor is converted into carbon, for example, during a pyrolysis process.

In a structurally advantageous embodiment, the outer mold segments are advanced via a pressing device. The pressing device comprises, in particular, two pressing tools that are advanced toward one another in one direction. By appropriately designing the pressing device, the outer mold segments can be advanced along their axes of movement toward the fiber device to achieve the appropriate compaction of the fiber device. A pressing device with a single pressing direction can then achieve compaction of the fiber device across the outer mold segments in several different axes of movement aligned toward the center.

In particular, the longitudinal object or the preform for the longitudinal object is a hollow body (tube) or a rod. The method according to the invention allows the production of tubes or rods with a precise outer diameter and a high fiber volume content. Tubes with a precise wall thickness and a precise shape (in particular, a circular cross-section), and in particular, with greater wall thickness, can be produced.

It is advantageous if the outer mold segments each have an inner side, whereby at least in one end position or in one end position range of the outer mold segments, the inner sides of the outer mold segments define an outer shape of the longitudinal object or preform for the longitudinal object. This allows for compaction with shaping.

• 1 eine schematische Darstellung eines Ausführungsbeispiels einer erfindungsgemäßen Presswerkzeugvorrichtung;
• 2 eine perspektivische Darstellung von Außenformsegmenten der Presswerkzeugvorrichtung gemäß 1;
• 3 eine Schnittansicht längs der Linie 3-3 gemäß 1, wobei zusätzliche eine Presseinrichtung gezeigt ist, in einem ersten Stadium eines Pressvorgangs mit Verdichtung einer Fasereinrichtung;
• 4 die gleiche Ansicht wie 3 in einem zweiten Stadium des Verdichtungsvorgangs;
• 5 die gleiche Ansicht wie 3 in einem dritten Stadium (Endstadium) des Verdichtungsvorgangs;
• 6 ein Ausführungsbeispiel eines hergestellten Längsobjekts in Form eines Rohres;
• 7 das Rohr gemäß 6 nach einer Pyrolyse;
• 8 eine schematische Darstellung eines weiteren Ausführungsbeispiels von Außenformsegmenten;
• 9 eine schematische Darstellung eines weiteren Ausführungsbeispiels von Außenformsegmenten;
• 10 eine schematische Ansicht eines Ausführungsbeispiels, wobei zwei Folien verwendet werden;
• 11 bis 14 ein Ausführungsbeispiel einer Teildarstellung einer Presswerkzeugvorrichtung mit zwei Außenformsegmenten; und
• 15 ein weiteres Ausführungsbeispiel einer Teildarstellung einer erfindungsgemäßen Pressvorrichtung mit Außenformsegment-Scheiben.

The following description of preferred embodiments, taken in conjunction with the drawings, serves to further explain the invention. They show:

• 1 a schematic representation of an embodiment of a pressing tool device according to the invention;
• 2 a perspective view of outer mold segments of the press tool device according to 1 ;
• 3 a sectional view along the line 3-3 according to 1 , wherein additionally a pressing device is shown, in a first stage of a pressing process with compaction of a fiber device;
• 4 the same view as 3 in a second stage of the compaction process;
• 5 the same view as 3 in a third stage (final stage) of the compaction process;
• 6 an embodiment of a manufactured longitudinal object in the form of a tube;
• 7 the pipe according to 6 after pyrolysis;
• 8 a schematic representation of another embodiment of outer mold segments;
• 9 a schematic representation of another embodiment of outer mold segments;
• 10 a schematic view of an embodiment using two foils;
• 11 to 14 an embodiment of a partial representation of a pressing tool device with two outer mold segments; and
• 15 a further embodiment of a partial representation of a pressing device according to the invention with outer mold segment discs.

An embodiment of a pressing tool device according to the invention, which is shown in the 1 to 5 shown schematically and designated 10, is used to produce longitudinal objects from a fiber composite material. These longitudinal objects are, in particular, tubes or rods.

An embodiment of the pressing tool device 10 comprises a first sleeve 12 and a second sleeve 14, wherein the first sleeve 12 and the second sleeve 14 are spaced apart from one another in a longitudinal axis 16.

A receptacle 18 is located between the first sleeve 12 and the second sleeve 14. The receptacle 18 serves to position a fiber assembly 20 to be pressed. The fiber assembly 20 comprises fibers and a carbon precursor.

The fiber device 20 comprises, for example, prepreg elements.

In one embodiment, the fiber device 20 comprises a fiber knit. In the fiber knit, the fibers have a 3D orientation.

The fiber device 20 is a fiber semi-finished product by means of which the longitudinal object or a preform for the longitudinal object is then produced.

In one embodiment, the longitudinal object or the pre-body is a tube (hollow body).

The pressing tool device 10 then comprises a core 22, which is in particular cylindrical. The core 22 extends along the longitudinal axis 16, wherein the longitudinal axis 16 is in particular a cylindrical axis. It is positioned on both the first sleeve 12 and the second sleeve 14. In particular, the first sleeve 12 and the second sleeve 14 are placed on the core 22. The sleeves 12, 14 serve as a stop for limiting the movement of the outer mold segments 24 along the movement axis 30 (see below).

In this embodiment, the receptacle 18 is an annular space formed around the core 22.

The pressing tool device 10 comprises a plurality of outer mold segments 24 as pressing tools. The outer mold segments 24 serve to compress the fiber device 20 from the outside.

At least two outer mold segments 24 are provided.

In the 2 to 5 In the embodiment shown for producing a pipe as a longitudinal object, wherein this pipe has a circular cross-section, six outer shape segments 24 are provided.

The respective outer mold segments 24 extend in an axis parallel to the longitudinal axis 16. They have an inner side 26, which faces the receptacle 18, and an outer side 28. The inner side 26 is designed such that the outer shape for the longitudinal object or of the pre-product for the longitudinal object is produced accordingly during a pressing process.

In one embodiment of a tube with a circular cross-section, the inner side 26 has the shape of a section of a cylindrical surface; in cross-section, this corresponds to a circular section.

In this embodiment, the inner sides 26 of the outer mold segments 24 form a lateral surface of a cylinder in the end position of the outer mold segments 24.

The outer mold segments 24 are each movably arranged with a movement axis 30. The movement axes 30 of different outer mold segments 24 have a different orientation. All movement axes 30 are transverse and, in particular, perpendicular to the longitudinal axis 16 of the receptacle 18.

The movement axes 30 meet at a center 32 and intersect in particular at the center 32. The center 32 is located in the receptacle 18.

The center 32 is in particular surrounded by the fiber device 20.

In the embodiment of a tube as a longitudinal object, the center 32 is positioned in the core 22. In an embodiment of a solid object, the center 32 is located in the fiber device 20.

In an embodiment in which a cylindrical object (tube or rod) is to be produced, the center 32 lies in particular on the cylinder axis.

The outer mold segments 24 can be moved along their respective movement axes 30 toward the center 32 of the fiber device 20 to perform compaction there. This will be explained in more detail below.

Adjacent outer mold segments 24 can be supported and guided against each other. A first outer mold segment 34 has first projections on a wall 36 facing an adjacent second outer mold segment 38. recesses 40. The first recesses 40 are spaced apart from one another in a direction parallel to the longitudinal axis 16. The recesses 40 extend along the wall 36 from the outer side 28 to the inner side 26.

Between adjacent first recesses 40, a first tooth 42 is located on the first outer mold segment 34. The first tooth 42 extends from the outer side 28 to the inner side 26.

The first recesses 40 are niches or recesses on the first outer mold segment 34 on the wall 36. The first teeth 42 between adjacent first recesses 40 are correspondingly non-recessed areas.

The second outer mold segment 38 has corresponding second recesses 46 and second teeth 48 on a wall 44 which faces the wall 36 of the adjacent first outer mold segment 34.

A respective first tooth 42 of the first outer shape segment 34 engages into an associated second recess 46 of the second outer shape segment 38. A second tooth 48 of the second outer shape segment 38 engages into an associated first recess 40 of the adjacent first outer shape segment 34.

The adjacent outer mold segments 34 and 38 are thereby connected to one another via a corresponding toothing 50, which is formed by the first recesses 40, the first teeth 42, the second recesses 46 and the second teeth 48.

The corresponding connection is on each outer mold segment 24 on both sides to the adjacent outer mold segment.

Since at least three outer mold segments 24 are present, each outer mold segment 24 has a circumferential direction 52 (cf. 2 ), to which the longitudinal axis 16 is perpendicular, has a nearest neighbor on both sides.

The outer mold segments 24 form a ring around the receptacle 18, wherein adjacent outer mold segments 24 can be supported on one another via the toothing 50.

The inner sides 26 of the outer mold segments 24 form a parting surface 54 toward the fiber device 20. Adjacent outer mold segments 34, 38 abut one another at the parting surface 54 due to the toothing 50. There (at least in the end position of the outer mold segments 24) there is a boundary line 56 between the adjacent outer mold segments 34, 38. This boundary line 56 has a direction change due to the toothing 50.

In the embodiment shown, the recesses 40, 46 and correspondingly also the teeth 42, 48 are rectangular or square in cross section.

The course of the boundary line 56 is meandering in a direction parallel to the longitudinal axis 16.

This change in direction of the boundary line 56 results in a labyrinth-like separation between adjacent outer mold segments 34, 38 at the separation surface 54. This prevents or at least complicates a displacement of fibers of the fiber device 20 into an area between adjacent outer mold segments 34, 38.

This effectively prevents fibers (or a film 80; see below) from being “squashed” between adjacent outer mold segments 34, 38.

In one embodiment, the outer mold segments 24 are guided via a guide device 58 ( 1 ) is mounted displaceably along its movement axis 30. Supporting/guiding adjacent outer mold segments 24 against each other is then unnecessary and, in particular, not provided.

In one embodiment, the guide device 58 is arranged and designed such that it lies outside the receptacle 18.

In one embodiment, the guide device 58 comprises at least one pair 60 of locating pins 62a, 62b.

The locating pins 62a, 62b are spaced apart from one another along the longitudinal axis 16.

The locating pin 62a is located on the first sleeve 12 and is fixed to the core 22. The locating pin 62b is located on the second sleeve 14 and is fixed to the core 22.

The locating pins 62a, 62b of a pair 60 are aligned parallel to each other and are aligned with the center 32.

In an embodiment in which a rotationally symmetrical object is to be produced, the locating pins 62a, 62b are each aligned radially (with respect to the longitudinal axis 16 as the axial axis).

A corresponding outer mold segment 24 is guided on the locating pins 62a, 62b with its movement axis 30. For this purpose, it has corresponding recesses 64 aligned with the locating pins 62a, 62b, by means of which it is slidably mounted on the locating pins 62a, 62b.

For feeding the outer mold segments 24 in their movement axis 30 to the center 32 and thus for compacting the fiber device 20, a feeding device 64 (cf. 3 , 4 , 5 ) is provided.

It is fundamentally possible for each outer mold segment 24 to be individually controlled and advanced along a movement axis 30.

In one embodiment, the feed device 64 is a pressing device 66. The pressing device 66 comprises a first pressing tool 68 and a second pressing tool 70. The first pressing tool 68 and the second pressing tool 70 are movable relative to each other in a direction 72. (Both pressing tools 68, 70 can be movable, or one pressing tool can be stationary and the other movable.)

The first pressing tool 68 and the second pressing tool 70 are each designed as a pressing mold with a first receptacle 74 (first pressing tool 68) and a second receptacle 76 (second pressing tool 70).

The first receptacle 74 and the second receptacle 76 are each adapted to the shape of the outer sides 28 of the outer mold segments 24, so that a movement of all outer mold segments 24 along their respective movement axis 30 is achieved by pressing in the direction 72.

In one embodiment, six outer mold segments 24 are provided.

The outer sides 28 form at least approximately a hexagon.

The first receptacle 74 and the second receptacle 76 are adapted to the hexagonal shape.

The first pressing tool 68 and the second pressing tool 70 act on the outer mold segments 24 in such a way that they are fed in a synchronized manner with their movement axis 30 in the direction of the center 72 of the fiber device 20 and carry out a compaction there.

In one embodiment, it is provided that an outer mold segment 24 extends over the longitudinal axis 16 of the receptacle 18 (cf. 1 ). As a result, an outer shape segment 24 is provided relative to the longitudinal axis 16, wherein the majority of the outer shape segments 24 (at least three) are related to the circumferential direction 52.

It is also possible in principle that outer mold segments 24 are divided relative to the longitudinal axis 16, so that in particular a plurality of outer mold segment discs, as in 15 indicated, is present.

In one embodiment, at least one film 80 is positioned between the fiber device 20 and the inner side 26 of the outer mold segments 24, and thereby in the receptacle 18. The film 80 is an aid in the production of the longitudinal object or the preform for the longitudinal object and generally does not remain on the longitudinal object.

The foil 80 is, in particular, a metal foil, and preferably a steel foil. In one embodiment, it has a thickness of 0.2 mm. In particular, the thickness is in the range between 0.1 mm and 0.3 mm.

The film 80 surrounds the fiber device 20. It covers transitions between adjacent outer mold segments 24 on the inner sides 26.

In one embodiment, a plurality of film layers is provided ( 10 ). For example, a film layer does not completely surround the fiber device 20. Another film layer is then arranged such that it touches or covers an edge 81 of the corresponding film layer to the fiber device 20. The entirety of the film layers surrounds the entire circumference of the fiber device 20 or the inner surfaces of the outer mold segments 24.

The fiber device 20 in the receptacle 18 is a fiber preform. The film 80 lies between the fiber preform and the outer mold segments 24 (in the receptacle 18). In addition to the effect of the toothing 50, it prevents the fibers from shifting into the intermediate area between adjacent outer mold segments 34, 38.

The toothing 50 further supports the film 80. This effectively prevents the film 80, and thus also the fibers, from being crushed at the separating surface 54 between adjacent outer mold segments 34, 38.

• In die Aufnahme 18 wird die Fasereinrichtung 20 eingebracht, d. h. es wird eine Faser-Preform hergestellt.

The inventive method works as follows:

• The fiber device 20 is inserted into the receptacle 18, ie a fiber preform is produced.

In the example shown ( 3 - 5 ) the fiber device 20 is placed on the core 22 with the outer mold segments 24 open.

The film 80 (or the film layers) is positioned over the fiber device 20.

The outer mold segments 24 are then placed on top, whereby they mesh with each other via the wavy teeth 50 (and are thus also connected to each other).

A pressing force is exerted on the pressing device 66 in the direction 72. In particular, an additional heat input is provided on the pressing tool device 10 and in particular via the outer mold segments 24 for the fiber device 20.

Due to the relative movement of the pressing tools 68, 70 in the direction 72, the outer forming tools 74 are advanced in their respective movement axes 30 towards the center 32.

In 3 a first stage is shown in which a pressing process begins on the fiber device 20.

In 4 a second stage of the pressing process is shown, in which a compaction of the fiber device 20 is already shown.

At the stage according to 4 compared to the stage according to 3 the pressing tools 78, 70 are further advanced in the direction 72.

In 5 A final stage of the pressing process is shown. The outer mold segments 24 are in their final position. In particular, the pressing tools 68, 70 are also in their final position and touching each other.

The carbon precursor is cured in the pressing tool device. This precursor is already contained in the fiber device 20 before the pressing process is carried out, with the fiber device 20 then being, in particular, a prepreg material.

Alternatively, it is possible that after completion of the pressing process within the pressing tool device, resin infiltration with subsequent resin curing takes place in the pressed fiber device 20.

The corresponding contour of the inner side 26 is adapted to the outer contour of the longitudinal object to be produced or the pre-product therefor.

In the final position according to 5 In particular, the inner sides 26 are flush with each other with a continuous transition, in particular without steps, gaps and the like.

The outer mold segments 24 are formed on their inner sides 26 in such a way that in the final position of the pressing tools 68, 70 the final position of the outer mold segments 24 is reached, and the corresponding contour is produced on the fiber device 20 as a fiber preform.

By means of the pressing tool device 10 according to the invention and by means of the method according to the invention, longitudinal objects with a precise outer diameter (and when using a core with a precise inner diameter) and with a precise wall thickness, such as pipes, can be produced and this with a uniform fiber volume content.

The production of the longitudinal object or the pre-product for the longitudinal object can be produced with a defined fiber orientation; the slipping of fibers at the separation surface 54 can be largely avoided and the formation of wrinkles at the separation surface 54 of fibers can also be largely prevented.

In particular, longitudinal objects can be produced which are delamination-free.

The use of short fibers and/or knitted fibers allows the production of 3D fiber-reinforced longitudinal objects. For example, delamination-free pyrolysis can be performed afterward. Delamination of knitted or woven fabric layers due to matrix shrinkage during pyrolysis can be largely prevented.

In general, the fiber volume content of fiber-knitted fabrics in the dry preform is relatively low. A high fiber volume content can be achieved through strong compression by the pressing tool device 10. The solution according to the invention allows for strong compression by means of the outer mold segments 24.

The 3D arrangement of the fibers in a fiber knit allows, for example, threads with a high load-bearing capacity to be produced.

In 6 a plan view of a pipe is shown, which is produced with the pressing tool device 10 (cf. 3 - 5 ) was manufactured.

This tube was manufactured with a carbon fiber knit and is the direct result of pressing with the pressing tool device 10.

In 7 the pipe is according to 6 after a further processing step, namely pyrolysis, a carbon fiber-reinforced porous carbon body was produced.

The pipe according to 7 can then, for example, be subjected to carbide former infiltration in order to produce a C/C-SiC tube.

Using the press tool device 10 according to the invention and the method according to the invention, for example, low-expansion housings for retroreflectors can be produced. Charging racks made of C/C and C/C-SiC can be produced. Heat transfer tubes, for example, can be produced from C/C-SiC or SiC/SiC.

For example, bearing sleeves for plain or ball bearings can be manufactured in high-temperature applications or in corrosive environments.

For example, combustion chambers for rocket engines can be manufactured.

The production of tubes or hollow bodies with a circular cross-section was described above. In principle, rods can also be produced.

Longitudinal objects 82 ( 8 , 9 ) which do not have a circular cross-section.

For this purpose, outer shape segments 84 are provided, which are adapted to the shape of the longitudinal object 82 and are designed, for example, as “corner pieces”.

Adjacent outer mold segments 84 are connected to one another by a toothing similar to that described above.

The respective outer mold segments 84 have respective movement axes 88 which meet at a center 90.

In the embodiment according to 8 four such outer mold segments 84 are provided.

In the embodiment according to 9 four such outer mold segments 84 are provided.

Otherwise, the functionality is as described above.

An embodiment was described above in which the outer shape segments 24 have two neighbors, wherein they are coupled to each neighbor via a toothing in order to obtain the corresponding meandering boundary line course on the lateral surface of the inner side.

In particular, at least three outer mold segments 24 are provided.

In another embodiment ( 11 to 14 ) a first outer mold segment 92 and a second outer mold segment 94 are provided (ie, two outer mold segments are provided). The first outer mold segment 92 has a first movement axis 96. The second outer mold segment 94 has a second movement axis 98.

The first movement axis 96 and the second movement axis 98 are coaxial to each other with opposite directions.

In principle, it is possible for one of the outer mold segments 92, 94 to be stationary and for the first outer mold segment 92 and the second outer mold segment 94 to move relative to one another in the first movement axis 96 and the second movement axis 98.

In principle, it is also possible for each outer mold segment 92, 94 to be moved along its movement axis 96, 98 during a pressing process.

A first toothing 100 and a second toothing 102 are provided, via which the first outer mold segment 92 and the second outer mold segment 94 are toothed together (and thereby also connected to each other) and thereby also coupled to each other.

During a pressing process by feeding along the first movement axis 96 and/or the second movement axis 98, wherein a corresponding fiber device 106 is positioned in a receptacle 104, a corresponding compaction of the fiber device 106 takes place ( 11 to 14 ).

It is basically possible that if, for example, an object 108 ( 14 ) with a circular cross-section, this is only done in a final step.

As can be seen from the 11 to 13 As can be seen, due to the provision of two outer mold segments 92, 94, initially only a sub-area 110a ( 11 ), 110b ( 12 ) of the fiber device 106 in contact with the outer mold segments 92, 94.

Otherwise, the press tool device with the outer mold segments 92, 94 functions as described above.

In another embodiment ( 15 ) a plurality of interlocking outer mold segments 112 are provided. The outer mold segments 112 are formed in several parts relative to the longitudinal axis 16 and are composed of corresponding discs 114. A plurality of discs 114 are connected to one another, for example, via a rod device 116 with threaded rods and nuts, and form the corresponding outer mold segment 112.

By appropriately shaping the discs 114, a toothing 118 is produced. Such an outer mold segment 112 with the discs 114 can be manufactured in a particularly simple manner, since, for example, each disc 114 can be manufactured by waterjet cutting, and no milling process is necessary for the recesses of the toothing 118.

To enable easy movement of the outer mold segments 112 when adjacent outer mold segments 112 mesh due to the toothing 118, the wall thickness of toothed sections can be reduced, for example, by grinding. Alternatively or additionally, it is possible to increase the widths of the recesses of the toothing 118. This can be achieved, for example, by inserting foils or the like between adjacent discs 114.

Otherwise, the press tool device with the outer mold segments 112 functions as described above.

List of reference symbols

10

Press tool device

12

first sleeve

14

second sleeve

16

Longitudinal axis

18

Recording

20

Fiber facility

22

core

24

Outer mold segment

26

inside

28

outside

30

axis of movement

32

center

34

first outer mold segment

36

wall

38

second outer mold segment

40

first recesses

42

first tooth

44

wall

46

second recesses

48

second teeth

50

Gearing

52

circumferential direction

54

Separation surface

56

border line

58

Guide device

60

Couple

62a, 62b

Dowel pins

64

Delivery device

66

Pressing device

68

first pressing tool

70

second pressing tool

72

Direction

74

first recording

76

second recording

80

film

81

edge

82

Longitudinal object

84

Outer mold segment

86

Gearing

88

axis of movement

90

center

92

first outer mold segment

94

second outer mold segment

96

first axis of movement

98

second axis of movement

100

first gearing

102

second gearing

104

Recording

106

Fiber facility

108

object

110a, 110b

Sub-area

112

Outer mold segment

114

disc

116

Rod device

118

Gearing

QUOTES CONTAINED IN THE DESCRIPTION

This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This 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

• DD 51 423 A [0003]
• EP 0 415 207 B1 [0004]
• DE 10 2012 106 117 A1 [0005]
• CN 207806629 U [0006]

Claims (20)

Press tool device for producing a longitudinal component from a fiber composite material or for producing a preform for such a component, wherein the longitudinal component is in particular a rod or a tube, comprising a receptacle (18; 104) for a fiber device (20; 106), wherein the receptacle (18; 104) is assigned a longitudinal axis (16), at least two outer mold segments (24; 92, 94), each having an inner side (26) facing the receptacle (18), wherein each outer mold segment (24) is assigned a movement axis (30; 96, 98) which is oriented transversely to the longitudinal axis (16) of the receptacle (18; 104), wherein the movement axes (30; 96, 98) of the outer mold segments (24) are aligned with a center (32), and wherein adjacent outer mold segments (24; 92, 94) are interlocked with one another, and a Feed device (64), by means of which at least one outer mold segment (24; 92, 94) is displaceable in its movement axis (30; 96, 98) for a pressing process on the fiber device (20; 106). Press tool device according to Claim 1 , characterized in that adjacent outer mold segments (34, 38; 92, 94) are coupled via a toothing (50; 100, 102), wherein a boundary line (56) between inner sides (26) of adjacent outer mold segments (34, 38; 92, 94) has a direction change course and is in particular meander-shaped. Press tool device according to Claim 1 or 2 , characterized in that - a first outer mold segment (34) has first recesses (40) and first teeth (42), wherein a first tooth (42) lies between adjacent first recesses (40), - a second outer mold segment (38), which is adjacent to the first outer mold segment (34), has second recesses (46) and second teeth (48), wherein the first teeth (42) are immersed in respective second recesses (46) and the second teeth (48) are immersed in respective first recesses (40). Press tool device according to Claim 3 , characterized by at least one of the following: - the first recesses (40) run on the first outer mold segment (34) from the inner side (26) to an outer side (28) opposite the inner side (26); - the second recesses (46) run on the second outer mold segment (38) from the inner side (26) to an outer side (28) opposite the inner side (26). Press tool device according to one of the preceding claims, characterized in that at least in an end position or in an end position region of the outer mold segments (24), the inner sides (26) of the outer mold segments (24) form a closed jacket surface and in particular adjacent outer mold segments (24) are flush with one another. Press tool device according to one of the preceding claims, characterized by at least three outer mold segments (24). Press tool device according to one of the preceding claims, characterized by at least one foil (80) which is positioned between the fiber device (20) and the inner side (26) of the outer mold segments (24), in particular with at least one of the following: - the at least one foil (80) is a metal foil and in particular a steel foil; - the at least one foil (80) has a thickness in the range between 0.1 mm and 0.3 mm and in particular has a thickness of 0.2 mm; - the at least one foil (80) bridges a transition on the inner sides (26) of adjacent outer mold segments (24), as seen from the fiber device (20). Press tool device according to one of the preceding claims, characterized in that the feed device (64) has a pressing device (66) with at least one pressing mold (68, 70), wherein the at least one pressing mold (68; 70) has a recess (75; 76) in which one or more outer mold segments (24) are positioned. Press tool device according to one of the preceding claims, characterized by a guide device (58) for guiding the outer mold segments (24) in their movement axes (30), wherein the guide device (58) is positioned outside the receptacle (18) and in particular has at least one dowel pin (62a; 62b). Press tool device according to one of the preceding claims, characterized in that a core (22) for the fiber device (20) is positioned in the receptacle (18). Press tool device according to one of the preceding claims, characterized in that the longitudinal object has a cylindrical shape with a circular cross-section and that the movement axes (30) are aligned radially with respect to the circular cross-section, wherein the center (32) lies on a cylinder axis, and wherein in particular at least six outer mold segments (24) are provided. Press tool device according to one of the preceding claims, characterized in that the outer mold segments (24) are formed continuously with respect to the longitudinal axis (16) of the receptacle (18) or that a plurality of outer mold segment discs (114) are provided with respect to the longitudinal axis (16) of the receptacle. Press tool device according to one of the preceding claims, characterized in that the fiber device (20) comprises at least one of the following: - short fibers, fiber scrims, fiber fabrics, braided fiber preforms, wound fiber preforms, embroidered fiber preforms, fiber tubes; - a fiber knit; - a carbon precursor and in particular prepreg material. Method for producing a longitudinal component from a fiber composite material or a precursor for such a longitudinal component, in which a fiber device (20) is positioned in a receptacle (18) and a plurality of outer mold segments (24), each with a movement axis (30), is provided, and in order to compress the fiber device (20), at least one outer mold segment (24) is advanced with a movement axis (30) transverse to a longitudinal axis (16) of the receptacle (18) relative to the fiber device (20), wherein the movement axes (30) of the outer mold segments (24) meet at a center (32), and wherein at least two outer mold segments (24) are provided and adjacent outer mold segments (24) are interlocked with one another. Procedure according to Claim 14 , characterized in that the center (32) in which the movement axes (30) meet is surrounded by the fiber device (20). Procedure according to Claim 14 or 15 , characterized in that at least one foil (80) and in particular metal foil is positioned between an inner side (26) of the outer mold segments (24) and the fiber device (20). Procedure according to one of the Claims 14 until 16 , characterized in that the fiber device (20) comprises at least one of the following: - short fibers, fiber scrims, fiber fabrics, braided fiber preforms, wound fiber preforms, embroidered fiber preforms, fiber tubes; - a fiber knit; - a carbon precursor and in particular prepreg material. Procedure according to one of the Claims 14 until 17 , characterized in that the delivery of the outer mold segments (24) takes place via a pressing device (66). Procedure according to one of the Claims 14 until 18 , characterized in that the longitudinal object or the pre-body for the longitudinal object is a tube or rod. Procedure according to one of the Claims 14 until 19 , characterized in that the outer shape segments (24) each have an inner side (26), wherein at least in an end position or an end position region of the outer shape segments (24), the inner sides (26) of the outer shape segments (24) predetermine an outer shape of the longitudinal object or pre-body for the longitudinal object as a lateral surface.