DE102014206904A1 - Method and device for producing a fiber-reinforced molded component - Google Patents

Abstract

A method for producing a fiber-reinforced molded component by means of a fillable hollow mandrel is proposed with the following steps: Providing the hollow mandrel (1) filling the hollow mandrel (1) with a magnetorheological fluid (15) Providing a magnetic field (19, 21) in at least a partial region of the hollow mandrel (1) to bring about solidification of the fluid (15); application of a fiber arrangement to at least the partial region of the mandrel (1).

Description

The present invention relates to a method for producing a fiber-reinforced molded component by means of a fillable hollow mandrel according to the preamble of claim 1. The invention further relates to an apparatus for performing the method according to claim 9.

Cores are usually used for the production of mold components with a cavity. Such a core can be a foam core which can remain in the component and a blow molding core can also be used which can be removed again after the shaping of the molded component, which takes place for example by means of an injection process, or can remain in the component. There are also known mold cores in sandwich construction, which have a honeycomb-shaped structure and can be used for the production of hollow components.

Also, in the manufacture of molded components by the application of a fiber assembly on a mandrel, it is necessary for structuring of the mandrel to provide a core to which the fiber assembly may be disposed, for example by means of a braiding process. As a material for the mandrel, a rigid foam or, for example, extruded polystyrene can be used, and a hollow mandrel can be used in the form, for example, a Blasformkerns. Such a blow molding core is removable after molding and can be filled in the braiding without pressurization with ambient air or, for example, with water.

Before an injection process subsequent to the braiding process, in which resin is introduced into the braid, a blow mold core filled with ambient air during the braiding process is also filled with a liquid medium during the infiltration process, which remains in the blow molder core during the curing process of the resin.

A blow mold core has the advantage that it can be emptied after the formation of the mold component and even if it remains in the component, the mass of the mold component can not rise significantly. A blowing mandrel filled with ambient air used in a braiding operation has the advantage that it does not have a large mass counteracting the handling by robot systems, linear guides and conveyor belts, but also the disadvantage that it is difficult to handle since the handling of the hollow blow molder core is difficult due to its handling low pressure stability and bending stability is problematic and the blow molder tends to collapse.

The low bending stiffness of the blow mold core causes the handling system to be laborious because the blow mold core must be simultaneously supported in many places, resulting in a large number of the aforementioned handling devices being necessary and reducing the transfer speed of the blow mold core, which in turn reduces the cycle speed low in the plant for the production of hollow components.

The low pressure stability of the blow mold core in turn means that it threatens to collapse when handled by the handling equipment and there is always the risk that it is crushed when gripped by the handling equipment and can be damaged.

Although a blow molding core also filled with water during the braiding process has a higher pressure stability, it can not increase the bending stiffness necessary for shaping more complex structures with different radii.

Based on DE 11 2011 105 014 T5 For example, a method for producing a fiber-reinforced synthetic resin part has become known. In the known method, a preform made of continuous fibers is placed in a cavity of a tool and introduced softened or molten thermoplastic resin into the cavity and pressed the preform after the distribution of the resin in the mold by a pushing-up against the wall of the tool, so that Resin penetrates into the preform and solidifies.

Based on this, the object of the present invention is to provide an improved method for the production of a fiber-reinforced molded component which permits an increase in the molding cycle speed. Also, an apparatus for performing the method is to be created.

The invention has to solve this problem with respect to the method specified in claim 1 features. Advantageous embodiments of the method are described in the further claims. In addition, the invention has the object specified in claim 9 to solve the problem with respect to the device.

• – Bereitstellen des Hohlformkerns
• – Befüllen des Hohlformkerns mit einem magnetrheologischen Fluid
• – Bereitstellen eines Magnetfelds in zumindest einem Teilbereich des Hohlformkerns zur Herbeiführung einer Verfestigung des Fluids
• – Aufbringen einer Faseranordnung auf zumindest dem Teilbereich des Hohlformkerns.

The invention provides a method for producing a fiber-reinforced molded component by means of a fillable hollow core, comprising the following steps:

• - Providing the hollow mandrel
• - Fill the hollow mandrel with a magnetic rheological fluid
• - Providing a magnetic field in at least a portion of the hollow mandrel to bring about solidification of the fluid
• - Applying a fiber arrangement on at least the portion of the hollow mold core.

The invention is therefore characterized by the fact that a hollow mandrel is used for the production of the fiber-reinforced molded component, which may be a hollow component, which may be formed, for example, as a blow mold core. The hollow mandrel is filled with a magnetorheological fluid and a magnetic field is applied to at least a portion of the mandrel which causes the magnetorheological fluid to solidify in the region of the magnetic field and assume a structure which is suitable both for handling the mandrel in the solidified region by e.g. an automated handling device is suitable and dimensionally stable suitable for the application of a fiber assembly. It can therefore be increased by the action of the hollow mandrel with a magnetic field, the pressure stability of the hollow mandrel at the local solidified by the magnetic field and it can be attached to the solidified region and a fiber assembly, for example by means of a braiding process. By solidifying the magnetic rheological material in the hollow mandrel and the flexural rigidity of the hollow mandrel is increased.

It is also possible in this way to bring about hardening of the hollow mold core on a hollow mold core at a first subregion by the application of the magnetic field to the substructure, which can be used to grasp the hollow mold core from a gripping device of an automated handling device to a transport movement of the hollow mold core can be and can be pulled through a braided ring along a portion of the longitudinal extent of the hollow mandrel, for example. In the region of the braiding ring, a magnetic field can also be applied to the hollow mandrel, which results in aligning and solidifying the magnetorheological material located in the mandrel, so that both the compressive rigidity and the bending stiffness of the mandrel can be increased at the locally solidified region and a solid mandrel is provided for the braiding process.

It is provided according to a development of the method according to the invention that the magnetic field of at least the portion of the hollow mandrel is removed after the application of the fiber assembly. If the magnetic field is established, for example, by means of a coil arrangement through which current flows, the circuit can be interrupted after the application of the fiber arrangement to the solidified portion of the hollow mandrel, which results in the aligned and polarized particles of the magnetorheological fluid again assuming a disordered arrangement and the Hollow mold core in the previously locally solidified area again assumes its unconsolidated formation.

According to a development, the invention provides for the magnetic field to be provided at least in the area of a braiding device surrounding the hollow mandrel, so that the hollow mandrel assumes the structure of a substantially solid mandrel at the locally consolidated region and a fiber arrangement is applied to the region by means of a braiding process, for example can. The hollow mandrel can be moved translationally relative to the braiding device by also applying a magnetic field in the region of a gripping device acting on the hollow mandrel, which in turn leads to solidification of the hollow mandrel and thus the gripping device can grasp the hollow mandrel at the solidified region and move relative to the braiding device. During the movement, the magnetic field can be maintained in the region of the braiding device, so that a braid can be applied to the respective solidified region along the region of the hollow mandrel moving relative to the braiding device. In this way, a continuous braiding process can be brought about.

The hollow mandrel can be moved by means of an automated handling device relative to the braiding device and the handling device can have a device for providing the aforementioned magnetic field. The alternating use of two intermittently operating handling devices, a continuous braiding can be achieved by the hollow core is moved by a handling device in applied magnetic field along its range of movement relative to the braiding and this applies a magnetic field applied braid and shortly before the first handling device the end reaches its range of motion, the hollow mandrel is gripped by the second handling device in this magnetic field also generated and moved along the range of movement of the second handling device relative to the braiding device in an applied magnetic field. In this way, a continuously running braiding process or operation of applying a fiber arrangement to the hollow core is possible. During the movement of the hollow mandrel through the second handling device, the first Handling device in the context of their range of motion to return to the starting position and then take the hollow core again to another movement with the magnetic field.

It is provided according to a development of the method according to the invention, that the fluid has magnetically polarizable particles in the form of carbonyl iron powder, which are suspended in a carrier liquid. The degree of solidification of the fluid can be changed by a corresponding adjustment of the field strength of the magnetic field. Thus, it is possible, for example, to build up a magnetic field of lesser field strength in the region of the braiding device, so that a strength of the locally solidified region of the hollow mandrel that is sufficient for applying a fiber arrangement is sufficient, while in the area of the automated handling device or its gripping device a magnetic field of higher field strength is established, which causes the magnetorheological fluid solidified more than in the braiding and the hollow core of the gripping device can be safely gripped to build up a force that is large enough to the hollow mandrel with high speed of movement relative to To be able to move braiding device without the risk that the hollow core is squeezed by the gripping device.

The carrier liquid for receiving the polarisable particles may be mineral oil and / or synthetic oil and / or alcohol and / or water.

In addition to the use of a hollow mandrel with magnetorheological fluid for the braiding and / or transfer of the mandrel relative to an assembly for applying a fiber assembly, the invention also contemplates the use of the hollow mandrel filled with magnetorheological material in the resin infiltration into the deposited fiber assembly.

The inventive method is therefore characterized according to a development also by the fact that the hollow mandrel core with magnetically solidified material is spent together with the mold component in a tool for resin infiltration and a magnetic field is provided at least in a portion of the hollow mandrel and introduced a curable resin in the mold is maintained while maintaining the magnetic field and the magnetic field during at least a sub-interval of the time required for the curing of the resin time interval and after a predetermined degree of solidification of the resin, the magnetic field is removed and the hollow core is emptied. Then, the molded component infiltrated by resin can be removed from the tool mold with at least partially cured resin.

Finally, the invention also provides a device for carrying out the method, wherein the device is characterized by an automated handling device with a gripping device for handling a hollow mold core filled with magnetorheological material and by a device for arranging a fiber arrangement on at least a portion of the hollow mandrel and at least one the means for magnetizing at least a portion of the hollow mandrel is formed.

The invention will be explained in more detail below with reference to the drawing. This shows in:

1 a schematic cross-sectional view of a held by a gripping unfilled Blasformkerns;

2 a schematic representation for explaining the active principle of the solidification of a magnetic rheological fluid when applying a magnetic field;

3 in three superimposed images schematic representations of an unfilled Blasformkerns, filled with a magnetic rheumatism fluid Blasformkerns and filled with magnetrheological fluid Blasformkerns applied magnetic field;

4 similar to two schematic representations 1 a blow mold core filled with magnetorheological fluid in the non-directional state and in the state with polarized and oriented carbonyl iron powder particles; and

5 a schematic representation of an apparatus for performing the method.

1 The drawing shows in a cross-sectional view of a schematic structure of a hollow mandrel in the form of a Blasformkerns 1 that by a gripping device 2 is held, each having two L-shaped angles 3 having. The blow mold core 1 is in the illustrated embodiment, an elongated shell, due to the gripping movement through the two angles 3 assumes a largely rectangular shape and in the blow mold core 1 there is no filling medium arranged. Because in the blow mold core 1 no filling medium is found, the blow mold core 1 from the two angles 3 crushed.

The transmission of a force over the angles 3 on the blow mold core 1 to bring about a Movement of the blow mold core 1 is almost impossible and becomes more difficult the larger the body of the blow mold core 1 in cross-section becomes.

2 shows a schematic structure for explaining the active principle of magnetic rheological fluids. In the upper illustration of the 2 is the switch 4 an electrical circuit with a coil 5 open and one in the open area 7 an iron core 6 arranged magnetrheological fluid has a disordered arrangement of the carbonyl iron powder particles suspended in it 8th on. Once the circuit is closed, it builds up in the gap 7 a magnetic field, the particles 8th are polarized and align themselves along the magnetic field lines, the magnetic rheological fluid solidifies and changes within a few milliseconds from the liquid to a substantially solid state.

Finds this process in a hollow core 1 instead of being filled with the magnetic rheological fluid, the outer shell solidifies within a few milliseconds 9 ( 1 ) and the hollow core or blow mold core 3 assumes a pressure-stable and rigid outer contour.

3 The drawing shows an unfilled Blasformkern 1 which has an elongated, tubular configuration and in the region of an open end 10 a connection device 11 For an electrical energy source, not shown. At the, the open end 10 opposite end region 12 is the blow mold core 1 formed closed, so that within the outer shell 13 an interior 14 which forms for receiving a magnetic rheological fluid 15 is provided.

The middle representation of the 3 shows that with a magnetrheological fluid 15 filled interior 14 with in the fluid 15 suspended, undirected particles 8th , Will, as shown in the lower part of the 3 is shown at the connection device 11 connected to an electrical power source, then the particles become 8th polarize and align along the magnetic flux lines and the fluid 15 assumes a largely fixed configuration and solidifies in this way the outer shell 13 of the blow mold core 1 ,

4 The drawing shows a configuration similar to that in the upper diagram 1 with a blow mold core 1 that from the angles 3 the gripping device 2 is largely included and in the interior 14 a magnetic rheological fluid 15 is arranged, the carbonyl iron powder particles 8th undirected.

About a non-illustrated connection device can at the angles 3 the gripping device 2 a schematically illustrated power source 16 be connected so that is between the two angles 3 forming a magnetic field, which ensures that the particles 8th in the fluid 15 aligned and polarized and become the magnetorheological fluid 15 solidified. This is evident from the fact that the outer shell 13 a largely rectangular configuration occupies and thus on the angle 3 a holding force on the outer shell 13 can be transferred, which can be used to the blow mold core 1 to transport.

5 , The drawing shows a schematic representation of a device 17 for carrying out the method according to the invention for producing a fiber-reinforced molded component 1 using the blow mold core 1 ,

With the device 17 a tubular hollow component is to be produced, which may be, for example, a wheel hub, not shown.

The device 17 has for this purpose a schematically illustrated braiding device 18 on, which is designed as a ring and with a non-illustrated carbon fiber roving on the blow mold core 1 can be attached by means of a braiding process. The wheel hub to be produced has a tubular configuration and is produced by the fact that within the outer contour of the braiding device 18 A magnetic field can be generated, which ensures that the particles 8th of the magnetic rheological fluid 15 Align and get the fluid 15 solidified and so the outer shell 13 in the detection range of the magnetic field 19 assumes a largely fixed configuration and so the carbon fiber on the tubular outer contour of the blow mold core 1 can be arranged to form a braid, which can then be subsequently impregnated by means of a Harzinfiltrationsvorgangs.

Since the wheel hub should have a predetermined longitudinal extent, the blow mold core 1 while maintaining the magnetic field 19 translational relative to the braiding device 18 moved by the handling device 20 in the form of a robot, with the already explained gripping device 2 is provided. For movement of the blow mold core 1 relative to the braiding device 18 is to the gripping device 2 or the relative to each other movable angle 3 connected to a non-illustrated power source, which ensures that in the detection range of the magnetic field 21 the gripping device 2 the magnetorheological fluid 15 solidified and the outer shell 13 of the blow mold core 1 forms a suitable for power transmission pressure-stable and rigid structure, which is suitable for the blow mold core 1 from the robot arm 22 relative to the braiding device 18 can be transported.

By using a second, identical to the robot 20 trained, but not shown robot, for a movement of the blow mold core 1 relative to the braiding device 18 ensures when the robotic arm 22 After it has reached its end position of its travel range, returns to its original position, a continuous manufacturing process for the fiber-reinforced molded component in the form of the example mentioned hub can be achieved.

The local consolidation of the blow mold core 1 in the range of the magnetic field of the handling device 20 ensures that a significantly higher transfer speed of the blow mold core 1 relative to the braiding device 18 can be achieved than has hitherto been the case. This allows the cycle time of the manufacturing device 17 be increased and the expenditure on equipment for the transfer of the blow mold core 1 relative to the braiding device 18 can be reduced as the number of so far for the transport of the blow mold core 1 necessary handling equipment, linear guides and conveyor belts can be reduced.

With regard to features of the invention which are not explained in greater detail above, reference is expressly made to the claims and the drawings, moreover.

LIST OF REFERENCE NUMBERS

1

Blow mold core, hollow core

2

gripper

3

angle

4

switch

5

Kitchen sink

6

iron core

7

open area, gap

8th

Carbonyleisenpulverpartikel

9

outer shell

10

open end

11

connecting device

12

end

13

outer shell

14

inner space

15

magnetic rheological fluid

16

power source

17

contraption

18

braider

19

magnetic field

20

robot

21

magnetic field

22

robot arm

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• DE 112011105014 T5 [0009]

Claims (9)

Process for the production of a fiber-reinforced molded component by means of a fillable hollow core with the following steps: - providing the hollow core ( 1 ) - filling the hollow core ( 1 ) with a magnetorheological fluid ( 15 ) - providing a magnetic field ( 19 . 21 ) in at least a portion of the hollow core ( 1 ) to effect solidification of the fluid ( 15 ) - applying a fiber arrangement on at least the partial area of the hollow core ( 1 ). Method according to claim 1, characterized in that the magnetic field ( 19 . 21 ) of at least the portion of the hollow mandrel ( 1 ) is removed after application of the fiber assembly. Method according to claim 1 or 2, characterized in that the magnetic field ( 19 . 21 ) at least in the region of a hollow core ( 1 ) surrounding braiding device ( 18 ) provided. Method according to one of the preceding claims, characterized in that the hollow core ( 1 ) by means of an automated handling device ( 20 ) is moved relative to a braiding device and the handling device ( 20 ) means for providing a magnetic field ( 19 . 21 ) having. Method according to one of the preceding claims, characterized in that the fluid ( 15 ) magnetically polarizable particles ( 8th ) in the form of carbonyl iron powder suspended in a carrier liquid. Method according to one of the preceding claims, characterized in that for adjusting the degree of solidification of the fluid ( 15 ) the field strength of the magnetic field is changed. Method according to one of the preceding claims, characterized in that the carrier liquid used is mineral oil and / or synthetic oil and / or alcohol and / or water. Method according to one of the preceding claims, characterized by the following steps: - moving the hollow core ( 1 ) with magnetically solidifiable fluid ( 15 ) together with the mold component into a resin infiltration tool - providing a magnetic field at least in a partial region of the mold core - introducing a curable resin into the mold while maintaining the magnetic field - maintaining the magnetic field during the curing process of the resin - removing the magnetic field - emptying the hollow mold core. Contraption ( 17 ) for carrying out the method according to one of the preceding claims, characterized by an automated handling device ( 20 ) with a gripping device ( 2 ) for handling a magnetorheological material ( 15 ) filled hollow core ( 1 ) and a facility ( 18 ) for arranging a fiber arrangement on at least one subregion of the hollow mandrel (US Pat. 1 ), whereby at least one of the facilities ( 2 ; 18 ) for magnetizing at least a portion of the hollow mandrel ( 1 ) is trained.

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