WO2011124351A1

WO2011124351A1 - Method for producing continuous fibre reinforced hollow shaped bodies

Info

Publication number: WO2011124351A1
Application number: PCT/EP2011/001589
Authority: WO
Inventors: Peter Michel; Mustafa Yildirim; Andreas LÖFFLER
Original assignee: Rehau Ag + Co
Priority date: 2010-03-30
Filing date: 2011-03-30
Publication date: 2011-10-13
Also published as: DE102010013450A1

Abstract

The invention relates to a method for producing a continuous fibre reinforced hollow shaped body (11), and also to a hollow shaped body (11) produced by said method and to a motor vehicle component having a hollow shaped body (11). The hollow shaped body (11) is produced by forming continuous fibre reinforced inserts (1, 2, 14) in a forming tool (8), wherein separating means (3, 13) are provided which partially space the inserts (1, 2, 14) from one another.

Description

METHOD FOR THE PRODUCTION OF ENDLESS FIBER AMPLIFIERS

HOLLOW SHAPED BODIES

The present invention relates to a method for producing a continuous fiber-reinforced hollow molded body, and to a hollow molded body produced by this method and to a motor vehicle component having a hollow molded body. It is known to increase the stiffness of a continuous fiber reinforced molded body by taking the form of a hollow profile. Such hollow profiles are made in particular by winding techniques in accordance with complex systems and with long cycle times. In addition to the elaborate production of such hollow profiles is still a disadvantage that these process reasons are limited to simple geometries.

It is therefore an object of this invention to provide a method which allows a simplified and more cost-effective production of an endless fiber-reinforced hollow molded body with a simultaneously more complex geometry. The object is achieved according to the invention by a process for the production of continuous fiber-reinforced hollow moldings, which comprises the following steps:

Providing substantially flat-shaped continuous fiber-reinforced inserts,

Application of a release agent to at least a portion of the surface of a first insert, wherein the portion is substantially associated with the forming area of a subsequent forming step,

Positioning a second insert on the first insert such that the parting means defines at least one partial parting plane between the two inserters,

Transfer of stacked inserts between the at least one cavity defining tool walls of a forming tool,

Closing the forming tool,

- 1 -

CONFIRMED U NGSKOPI E Forming at least one of the two depositors by means of a medium subjected to vacuum or pressure, so that the insert removes from the partial parting plane and applies it to the associated tool wall and at least one cavity is formed between the inserts, passing through the cavity of the forming tool is defined

Consolidate the inserts within the forming tool,

Opening the forming tool and removal of the hollow molded body.

Advantageously, the method according to the invention makes it possible to produce end-of-fiber-reinforced hollow moldings having a complex geometry which deviate, in particular, from a pure profile structure. The method according to the invention makes it possible to increase the complexity of continuous-fiber-reinforced components and to further improve their lightweight construction potential - with at the same time reduced investment in equipment and a reduced number of process steps and, consequently, a considerable cost reduction. At the same time, the forming tool serves as a hold-down for the edge areas of the inserts in order to achieve the most uniform shaping behavior of the inserts by keeping them under tension during the forming process. The forming tool can in particular be designed as a press tool. In an advantageous embodiment of the method according to the invention can be applied to a further portion of the separation plane side facing away from one of the two inserts another release agent and then a third depositor so positioned on one of the two depositors that the further release agent at least one further partial separation plane between one of the two inserts and the third inserter defined, wherein the further portion is also substantially associated with a forming area of the subsequent forming step. Analogously, a transfer of stacked inserts takes place between the at least one cavity defining tool walls of a forming tool and the closing of the forming tool. Subsequently, at least one of the three inserts is formed by means of a medium subjected to vacuum or pressure so that the insert moves away from the partial parting plane (first and / or further parting plane) and abuts against the associated tool wall and at least one between the inserts Cavity is formed, which is defined by the cavity of the forming tool. Consolidation of the inserts also takes place within the forming tool. Finally, the opening of the forming tool and the removal of the finished hollow shaped body done. By providing at least a third insert, the rigidity of the hollow molded body can advantageously be further increased. One of the inserts is arranged so that it lies as a supporting body, in particular as a support rib, within the cavity formed by the further inserter. The inserts consolidate in the areas that are not defined by the partial areas or the forming areas.

The inserts can be at least partially preheated before the forming step, so that increases the flexibility of the depositors. The preheating can be done by convection heating and / or infrared radiation. Preferably within a convection and / or within an infrared continuous furnace. The preheating advantageously makes it possible to increase the degrees of deformation of the inserts (e.g., organic sheets). The inserts are preferably multi-layered and further preferably consist of several endless fiber-reinforced mats, which are combined to form a deposit.

The release agents used may be formed as a film, a gel, a pasty mass or a fluid medium. The abovementioned release agents can be applied simply and also automatically to the inserts. The release agents can be advantageously applied very thin surface, so that the mass weights of the release agent have no appreciable effect on the finished hollow molded body in the event that the release agent after completion of the manufacturing process can not be removed from the cavity or should.

The release agent may be formed as an expandable shell. The release agent may be an expandable shell. The expandable sheath may in particular be a tube (e.g., foil tube) or a balloon sheath. In this advantageous embodiment of the release agent, the expandable sheath can both prevent the unwanted bonding (in particular gluing) of the inserts, as well as support the shaping in the forming tool by the expandable sheath is expanded with a pressure-fed fluid and presses the depositors to the associated Werkzeugwandungen. By discharging the pressure or the fluid within the expandable shell, moreover, it can generally be easily removed from the hollow molding and / or reused.

The release agent preferably contains as the base component silicone or Teflon. Both abovementioned basic components have no ad- behave and behave especially as the base components of the release agent.

The fiber reinforcement can be formed by mineral fibers, in particular glass fibers, and / or carbon fibers, and / or aramid fibers, and / or polymeric fibers, and / or synthetic fibers, and / or from fibers of renewable raw materials. The fiber length within the inserts has in particular a value of at least 12 mm. The fiber volume fraction within the inserts preferably has a value between 15 and 50%.

The inserts preferably have a thermosetting or a thermoplastic or an elastomeric plastic matrix. In particular, a thermoplastic matrix of the continuous fiber-reinforced inserts has proven to be suitable for implementing the method according to the invention.

In the forming tool can on the hollow molding at the edge of a circumferential plastic piping by injection molding by injection molding and / or by the additional insertion of GMT pieces and / or by a shot-pot technique and / or by inserting sealing cords and / or by the insertion of a sealing film can be generated. The edge of the plastic wrap around the edge makes it possible to achieve a homogeneous consolidation pressure within the forming tool.

The cavity of a hollow molded article produced by the method according to the invention is preferably closed on all sides or as a channel with a closed wall for transporting a fluid and / or for receiving cables, hoses or wires. An all-round closed wall of the Hohformkörpers serves primarily to achieve a high rigidity, especially on torsional and / or bending loads. If, on the other hand, the cavity has at least one opening to the outside, advantageously additional functional properties can be met, such as, for example, the transport of fluids or the guidance of hoses or wires within the cavity.

The hollow molded body according to the invention may be part of a motor vehicle component, wherein the component is in particular a door, an energy absorber, a battery housing, a battery carrier, a bumper, a bending beam, a body element or a sill can. The hollow molded body, as well as the method according to the invention, can also be used in industrial applications, for sports equipment or in the construction sector.

embodiments

In the following the invention will be explained with reference to an exemplary embodiments illustrative drawing. They show schematically:

1 shows a sequence of the method according to the invention, FIG. 2 shows a further sequence of the method according to the invention

3 shows a hollow molded article produced by the process according to the invention. FIG. 4 shows a further hollow molded article produced according to the invention

method

Fig. 5 shows another hollow molded body with closed cavities produced by the method according to the invention

Fig. 6 shows another sequence of the method according to the invention

Fig. 7 shows another sequence of the method according to the invention

FIG. 1 schematically shows the sequence of the method according to the invention for the production of continuous-fiber-reinforced hollow molded articles 11 comprising the following steps:

(a) (top view) Provision of substantially flat-shaped continuous fiber-reinforced inserts 1, 2, (b) (top view) application of a release agent 3 on at least a portion 4 of the surface of a first insert 1, wherein the portion 4 substantially the forming area of a subsequent Forming step is assigned, (c + d) (side view) positioning a second insert 2 on the first insert 1 such that the parting means 3 defines at least a first partial parting plane 5 between the two inserts 1, 2, (e) (sectional view) transfer of the stacked inserts 1, 2 between the at least one cavity 6a, 6b defining tool walls 7a, 7b of a forming tool 8,

(f) (sectional view) Closing the forming tool 8 and forming an insert 2 by means of a medium 9 charged with vacuum so that the insert 2 moves away from the partial parting plane 5 and abuts against the associated tool wall 7a and between the inserts 1 , 2 a cavity 10 is formed, which is defined by the cavity 6 a, 6 b of the forming tool. In the following (not shown in detail), the inserts 1, 2 are inside the forming tool 8 and the opening of the forming tool 8, and the removal of the hollow molded body 1 1. As an alternative method variant, the positioning of a second insert 2 on the first insert is already within of the forming tool 8. In the embodiment shown, the inserts 1, 2 are at least partially preheated prior to the forming step, so that the flexibility of the inserts 1, 2 increases. The preheating is done by a combination of convection heating and infrared radiation within a convection and within an infrared continuous furnace. The release agent 3 shown is a film 3 which contains silicone as the base component. The fiber reinforcement is formed by mineral fibers, in particular glass fibers, and by carbon fibers. The mean fiber length within the inserts 1, 2 has a value of at least 50 mm. The inserts have a thermoplastic matrix of PP, PA or P BT / P ET.

FIG. 2 schematically shows the sequence of a further process according to the invention for the production of continuous-fiber-reinforced hollow molded articles 11 comprising the following steps:

(Side view) Provision of substantially flat-shaped continuous fiber-reinforced inserts 1, 2 and application of a release agent 3 to at least a portion 4 of the surface of a first insert 1, wherein the portion 4 in Positioning of a second insert 2 on the first insert 1 is such that the separating means 3 defines at least a first partial parting plane 5 between the two inserts 1, 2, and then the application of a further separating means 13 on a further portion 12 of the separating plane 5 opposite side of an insert 2,

(b) (side view) a third insert 14 is positioned on the one inserter 2 such that the further parting means 13 defines at least one further parting plane 15 between the one inserter 2 and the third inserter 14, the further parting region 12 also is essentially assigned to a forming area of the subsequent forming step,

(Sectional representation) transfer of the stacked inserts 1, 2, 14 between the cavity walls 6a, 6b defining tool walls 7a, 7b of a forming tool 8,

(Sectional view) closing the forming tool 8 and forming the two inserts 1 and 14 by means of a pressurized medium 9, so that the depositors 1, 14 from the partial parting lines 5 and 15 remove and create their associated tool walls 7a, 7b and between the inserts 1, 2, 14 cavities 10a and 10b are formed, which are defined by the cavity 6a, 6b of the forming tool 8. In the following (not shown in detail), the inserts 1, 2, 14 are consolidated within the forming tool 8, in particular in the edge region of the inserts 1, 2, 14 and the opening of the forming tool 8, as well as the removal of the hollow shaped body 11. The between the formed inserts 1, 14 lying insert 2 remains substantially in its original shape and provides as a rib within the two cavities 10 a, b for a further improved stiffening and reinforcement of the hollow body 1 according to the invention 1. As an alternative method variant, the positioning of the insert 1, 2 takes place here as well In the exemplary embodiment shown, the inserts 1, 2, 14 are at least partially preheated before the forming step, so that the flexibility of the inserts 1, 2, 14 is increased. The preheating is done by a convection heating within a convection oven. The shown Release agent 3, 13 are formed as pasty mass 3, 13 which contains Teflon as the base component. The fiber reinforcement is formed by aramid fibers. The mean fiber length within the inserts 1, 2, 14 has a value of at least 50 mm. The inserts have a thermosetting plastic matrix of epoxy or PU or UP (unsaturated polyester resins). In the forming tool is on the hollow molding edge of a circumferential plastic piping 16 by injection molding by injection molding and / or by the additional insertion of GMT pieces and / or by a shot-pot technique and / or by inserting sealing cords and / or by Inserting a sealing film produced. FIG. 3 shows a three-dimensional representation of a hollow shaped body 1 1 produced by the method described in FIG. 1. The hollow space 10 is designed as a channel 10 with a closed wall for transporting a fluid and / or for receiving cables, hoses or wires. The hollow shaped body 11 is part of a bending beam of a motor vehicle.

4 shows a three-dimensional representation of a molded hollow body 1 1 produced with the method described in Figure 2. The cavities 10 a, b are as channels 10 a, b with a closed wall for transporting a fluid and / or for receiving cables, hoses or Wires trained. The hollow body 11 is part of a door of a motor vehicle. The insert 2 serves as an additional stiffening rib within the cavities 10 a, b. The hollow molded body 11 has at its edge a circumferential plastic piping 16 on which is molded by means of a plasticizing and injection unit coupled to the forming tool 8 in an injection molding process. FIGS. 5a (three-dimensional representation) and FIG. 5b (side view) show a schematic representation of a hollow shaped body 1 1 produced by the method according to the invention with a plurality of cavities 10 a, b, c, d. The cavities 10 a, b, c, d are closed on all sides and accordingly have closed ends. Due to its particularly increased rigidity, due to the completely closed cavities 10 a, b, c, d, the shown hollow body 11 can be designed, in particular, as an energy absorber of a motor vehicle. The release agents, not shown, are formed as a fluid medium. The release agents contain silicone as the base component and remain within the cavities 10 a, b, c, d. The hollow molded body 11 has at the edge a circumferential plastic piping 16 on by means of a the plasticizing and injection unit coupled to the forming tool 8 is molded in an injection molding process.

FIGS. 6a and 6b show schematically and in section parts of the sequence of the method according to the invention. The release agent 3 is in this case designed as an expandable shell 3 in the form of a film tube. The expandable shell 3 is applied to a portion of a first insert 1 and a second insert 2 is positioned so that the expandable shell 3 has a first partial parting plane 5 between the two inserts 1,

2 defined. The inserts are multi-layered and consist of several endless fiber-reinforced mats, which are combined to form a single insert. To

Closing of the forming tool 8 (see Fig. 6b) is an open end of the

expandable shell 3 by means of a closure element 20 (such as a plug) fluid-tight. In a supplementary process step is further the expandable shell

3 expands with a pressure-fed fluid (indicated by arrow) and the inserts 1, 2 pressed against the associated tool walls 7a, 7b (Expansionsdarstellungsprinzip see Fig .. 7). By releasing the pressure or the fluid within the expandable shell 3, this can be easily removed from the hollow molding and reused. In the forming tool 8 corresponding recesses in the region of the lead-outs of the expandable shell 3 (film tube) are provided.

FIG. 7 additionally shows, in comparison to FIG. 6, the actual expansion process of the expandable shell 3. Compared to FIG. 6, the inserts 1, 2 are constructed in a single layer. The expandable shell 3 is also not a film tube, but designed as a balloon envelope 3. Accordingly, a closure element can be dispensed with here.

- Claims -

Claims

claims

Process for the preparation of continuous fiber-reinforced hollow molded articles (11) comprising the following steps:

Providing substantially flat-shaped continuous fiber-reinforced inserts (1, 2),

Application of a release agent (3) to at least one partial region (4) of the surface of a first insert (1), wherein the partial region (4) is essentially assigned to the deformation region of a subsequent reshaping step,

Positioning a second insert (2) on the first insert (1) such that the parting means (3) defines at least one first parting plane (5) between the two inserts (1, 2),

Transfer of stacked inserts (1, 2) between the at least one cavity (6a, 6b) defining tool walls (7a, 7b) of a forming tool (8),

Closing the forming tool (8),

Forming at least one of the two inserts (1, 2) by means of a medium (9) applied with vacuum or pressure so that the insert (1, 2) moves away from the partial parting plane (5) and onto the tool wall (7a, 7b) and between the inserts (1, 2) at least one cavity (10) is formed, which is defined by the cavity (6a, 6b) of the forming tool, consolidating the insert (1, 2) within the forming tool (8),

Opening the forming tool (8) and removal of the hollow molded body (11).

A method according to claim 1, characterized in that on a further portion (12) of the separating plane (5) facing away from one of the two inserts (1, 2) applied a further release agent (13) and then a third inserter (14) so on one of the two inserts (1, 2) is positioned so that the further separating means (13) at least one further partial parting plane (15) between the one of the two depositors (1,

2) and the third inserter (14), the further part being Rich (12) is also assigned essentially a forming area of the subsequent forming step.

3. The method according to any one of the preceding claims, characterized in that the inserts (1, 2, 14) are at least partially preheated prior to the forming step, so that increases the flexibility of the depositors.

4. The method according to claim 3, characterized in that the preheating by convection heating and / or infrared radiation takes place, preferably within a convection and / or within an infrared continuous furnace.

5. The method according to any one of the preceding claims, characterized in that the release agent (3, 13) is a film, a gel, a pasty mass or a fluid medium.

6. The method according to any one of the preceding claims 1 to 4, characterized in that the separating means (3, 13) is an expandable shell.

7. The method according to any one of the preceding claims, characterized in that the release agent (3, 13) as the base component contains silicone or Teflon.

8. The method according to any one of the preceding claims, characterized in that the fiber reinforcement by mineral fibers, in particular glass fibers, and / or carbon fibers, and / or aramid fibers, and / or polymeric fibers, and / or synthetic see fibers and / or fibers of renewable resources is / are formed.

9. The method according to any one of the preceding claims, characterized in that the inserts (1, 2, 14) have a thermosetting or a thermoplastic or an elastomeric plastic matrix.

10. The method according to any one of the preceding claims, characterized in that in the forming tool (8) on the hollow molded body (11) peripherally a circumferential plastic piping (16) by injection molding by injection molding and / or by the additional insertion of GMT pieces and / or through a shot-pot technique and / or is created by the insertion of sealing cords and / or by inserting a sealing film.

11. Molded body produced according to one of claims 1 to 10, characterized in that the cavity (10) closed on all sides or as a channel (10) with a closed wall for transporting a fluid and / or for receiving cables, hoses or wires is formed.

12 motor vehicle component having a hollow molded body (1 1) according to claim 11, characterized in that the component is a door, an energy absorber, a battery case, a battery carrier, a bumper, a bending beam, a body member or a sill.