DE102013209143A1 - Method for producing a rotationally symmetrical fiber-plastic composite component, device for carrying out such a method and rotationally symmetrical fiber-plastic composite component - Google Patents

Abstract

Method for producing a rotationally symmetrical fiber-plastic composite component with at least one axial undercut section, first of all producing a dry fiber preform and subsequently processing the fiber preform in a pressure-assisted resin injection method, device for carrying out such a method and rotationally symmetrical fiber produced using such a method plastic composite component.

Description

The invention relates to a method for producing a rotationally symmetrical fiber-plastic composite component with at least one axial undercut section, a device for carrying out such a method and a rotationally symmetrical fiber-plastic composite component having at least one axial undercut section produced by such a method.

From the DE 10 2011 081 494 A1 a method is known for producing a bellows spring with transverse to the longitudinal axis of the bellows spring troughs and wave crests having waves from a particular smooth-surfaced tube of a fiber composite material with at least in the longitudinal direction of the tube extending, substantially parallel fibers, in a matrix of thermosetting or thermoplastic material embedded, wherein the transverse to the longitudinal axis of the bellows spring shafts are introduced by means of at least externally rotating relative to the tube, radially deliverable and profiled rolling elements in the deformable fiber composite material to propose an economical method for producing a bellows spring made of fiber composite, with the specifically predetermined properties let the bellows spring realize.

The invention has for its object to improve an aforementioned method and to provide an apparatus for performing such a method and a produced by such a method rotationally symmetrical fiber-plastic composite component with at least one axial undercut section. In particular, a production should be made possible with reduced effort. In particular, a cheap mass production should be possible. In particular, a tool-side effort is to be reduced. In particular, a high component quality is to be achieved. In particular, the requirements of high-quality components are combined with low production costs. In particular, hot-curing plastic systems should also be processable. In particular, a laying down of fibers should be facilitated. In particular, fibers should be able to be deposited in a targeted manner. In particular, when curing a predetermined temperature profile should be displayed. In particular, a stability of a fiber preform should be increased. In particular, a curing should be accelerated.

The object is achieved by a method for producing a rotationally symmetrical fiber-plastic composite component with at least one axial undercut section, wherein first a dry fiber preform is produced and subsequently the fiber preform is processed in a pressure-assisted plastic injection process. The plastic injection method may be a resin injection method. The plastic injection process may be over-pressure assisted, vacuum assisted, and / or atmospheric pressure assisted.

At least one of the following steps may be performed: preparing the fiber preform, inserting the fiber preform into a mold space formed between a tool having a radially inner tool surface and a tubular airtight membrane, rotating the tool and the fiber preform about an axis of rotation, thereby depositing the fiber preform the tool surface, expanding the membrane and evacuating the mold space, injecting a plastic, curing the plastic.

To make the fiber preform, fibers can be processed in a winding process. The fibers can be present as roving. During winding, the fibers and a winding spool can be moved axially relative to each other. During winding, the fibers and the winding spool can be moved in oscillating relationship to each other. The fibers may be wound as a hank, helical and / or orthocyclic. During winding, the reel spool can be moved relative to the fibers. During winding, the fibers can be moved relative to the reel spool. The fibers can be wound in a linear winding process and / or a flyer winding process.

The fiber preform may be mechanically stressed axially during winding to tension the wound fibers. The fiber preform may be subjected to a stabilizing agent during winding or after winding for mechanical stabilization. The stabilizing agent can act chemically or physically. The stabilizer may be a thermoplastic film, yarn, binder powder or sprayable binder. The stabilizing agent may be water that freezes on a cooled fiber preform.

The membrane can be drawn into the fiber preform. The fiber preform may have an outer diameter and a clear inner diameter. The membrane may have an outer diameter equal to or less than the inside diameter of the fiber preform when drawn. The fiber preform can be inserted into the opened tool and the tool can be closed. The tool can have a clear inner diameter. The fiber preform may have an outside diameter at insertion equal to or smaller than the inside diameter of the tool.

The tool can be rotated with the fiber preform at a predetermined minimum speed. The tool can be rotated with the fiber preform at a speed such that the fiber preform can be deposited under the action of centrifugal force on the tool surface. The fiber preform may be axially mechanically relieved during rotation to relax the wound fibers and allow the fiber preform to be deposited on the tool surface. The fiber preform can be twisted while laying down. The fiber preform may be rotated about the axis of rotation during deposition.

The mold cavity may be sealed prior to expanding the membrane and evacuating the mold cavity. The membrane can be expanded by means of a tempered pressure medium. The pressure medium can be heated. The pressure medium may be a fluid. The pressure medium can be air, water or oil based. The membrane can be expanded by atmospheric pressure. The mold space can be evacuated by applying negative pressure.

The deposition of the fibers in the mold can be favored by a plane Luftsog. In particular, the air suction can be generated by radial bores and negative pressure outside of the mold.

The negative pressure may be generated by an axial or radial turbine, such as a compressor.

In particular, the negative pressure may be generated by turbine blades, which are arranged on the outside of the mold and which are in operative connection with a stationary or relative to the mold moving housing, wherein the housing may have further turbine blades. By the movement of the turbine blades relative to the housing or with respect to the other turbine blades air is drawn from the mold through the holes.

The tool can be tempered during the injection and / or after the injection of the plastic. The tool can be heated and / or cooled. The tool can be tempered profile-controlled. The curing of the plastic can be assisted by microwave radiation. The microwave radiation can be applied from radially inside.

In addition, the solution of the problem underlying the invention with a device for carrying out such a method comprising a rotatable winding device having a rotation axis, a concentric to the rotation axis arranged first ring, a concentric to the rotation axis and axially spaced from the first ring second ring and an intermediate the ring arranged holding device and a rotatable tool having a rotation axis and a radially inner tool surface for limiting a mold space.

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

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

In addition, the solution of the problem underlying the invention with a rotationally symmetrical fiber-plastic composite component with at least one axial undercut section made according to such a method.

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

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

In summary and in other words, the invention thus provides, inter alia, a production method for a bellows spring. The bellows spring may be a fiber composite component. The bellows spring may be usable in a wheel carrier module. For the production, a special form of the Vacuum Assisted Resin Injection (VARI) process can be used, in which first a dry, textile preform is produced, which can subsequently be impregnated with resin and cured under pressure and temperature.

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

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

Hereinafter, embodiments of the invention will be described with reference to figures. From this description, further features and advantages. Concrete features of these embodiments may represent general features of the invention. Features associated with other features of these embodiments may also constitute individual features of the invention.

They show schematically and by way of example:

1 a winding device with a first ring, a second ring and a holding device and

2 a winding device in a tool with a radially inner surface.

2.1 shows the two turbine blades 2

1 shows a detail of a winding device 1 with a first ring 2 , a second ring 3 and a holding device 4 , The winding device 1 is part of a device for producing a rotationally symmetrical bellows spring made of a carbon fiber-resin composite. The winding device 1 serves to produce a dry fiber preform, which is subsequently processed in a resin injection process. The winding device 1 is about a rotation axis 5 rotatable.

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

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

Before or after winding becomes radially inside the rings 2 . 3 a tubular airtight membrane 8th moved in. The membrane 8th has a diameter having an inner diameter of the rings 2 . 3 roughly equivalent. After the winding process is by winding the roving 6 on the holding device 4 prepared fiber preform together with the winding spindle and the membrane 8th into a tool 9 brought in.

2 shows the winding device 1 in a tool 9 with a radially inner surface 10 , The tool 9 has a cylindrical shape. The tool 9 can be opened and closed to introduce the fiber preform. This is the tool 9 is along the axis of rotation 5 divisible.

The inner surface 10 has a wave-like shape. The tool 9 has inner ribs, like 11 , on. The inner ribs 11 each run in a circle on the inner surface 10 , The inner ribs 11 are axially spaced from each other. The inner ribs 11 each have a distance from each other, in about an axial width of a rib 11 equivalent. The inner ribs 11 have radially in each case a semicircular convexly rounded cross-section. A reason between the inner ribs 11 Each has a semicircular concave rounded cross-section. This shows the tool 9 a large inner diameter D and a small inner diameter d. The small inner diameter d can also be referred to as the diameter of a light.

The one by winding up the roving 6 on the holding device 4 initially produced fiber preform has a smaller outer diameter than the small inner diameter d of the tool 9 on. After the introduction of the fiber preform, the tool 9 and the fiber preform together with the winding spindle and the membrane 8th according to arrow f around the axis of rotation 5 turned. The Rings 2 . 3 according to arrows g, h displaced in the axial direction, so that the wound roving is relaxed. Under the influence of centrifugal force, the fiber preform becomes on the inner surface 10 stored. To support the deposition, the rings become 2 . 3 oscillating against each other.

The laying de fibers in the mold 9 can be favored by a plane Luftsog, by radial bores 13 and negative pressure outside the mold 9 is produced. The negative pressure is generated by an axial or radial turbine (or compressor) in which the rotating mold 9 outside turbine blades 14 having, in operative connection with a stationary housing 16 stand, which other turbine blades 15 may have and air from the tool 9 through the holes 18 draws. 2.1 shows a section through the device at the position AA. It shows 2 the position of the turbine blades 14 and 15 ,

After placing the fiber preform on the inner surface 10 become the rings 2 . 3 as far as shifted according to the arrows g, h, until they respectively on the tool 9 lie tightly and between the tool 9 , the rings 2 . 3 and the membrane 8th a closed form space 12 is formed. The following is the shape space 12 evacuated and the membrane 8th radially expanded so that the fiber preform between the tool 9 and the membrane 8th is fixed largely air-free. To expand the membrane 8th becomes the shape space 12 with negative pressure and the membrane 8th acted upon radially from the inside with a heated pressure medium. Below is in the form space 12 injected a resin and thus the fiber preform impregnated under vacuum with resin. To evacuate the form space 12 and to allow injection of resin, has at least one of the rings 2 . 3 in the form space 12 reaching channels.

Subsequently, the injected resin is cured. This is an internal pressure in the membrane 8th elevated. Besides that is the tool 9 heated. In addition, can be made from radially inside a Mikrowellenbeaufschlagung.

Finally, the bellows spring is removed from the mold and trimmed at the ends, so that the rings 2 . 3 can be removed. The device is automatically cleaned and a new process can begin.

LIST OF REFERENCE NUMBERS

1

winding device

2

first ring

3

second ring

4

holder

5

axis of rotation

6

roving

7

roving package

8th

membrane

9

Tool

10

surface

11

internal rib

12

cavity

13

radial bore in the mold

14

Turbine blades on the tool

15

Turbine blades on the housing

16

casing

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 102011081494 A1 [0002]

Claims (24)

Method for producing a rotationally symmetrical fiber-plastic composite component having at least one axial undercut section, characterized in that first a dry fiber preform is produced and subsequently the fiber preform is processed in a pressure-assisted resin injection process. A method according to claim 1, characterized in that at least one of the following steps is carried out - producing the fiber preform, - introducing the fiber preform into one between a tool ( 9 ) with a radially inner tool surface ( 10 ) and a tubular airtight membrane ( 8th ) formed form space ( 12 ), - turning the tool ( 9 ) and the fiber preform about a rotation axis ( 5 ), - thereby placing the fiber preform on the tool surface ( 10 ), - expanding the membrane ( 8th ) and evacuation of the mold space ( 12 ), - injecting a plastic, - curing the plastic. A method according to claim 2, characterized in that for producing the fiber preform fibers are processed in a winding process. A method according to claim 3, characterized in that the fibers are wound as a trickle winding, helically and / or orthocyclically. Method according to at least one of claims 3-4, characterized in that the fibers are wound in a linear winding process and / or a flyer winding process. Method according to at least one of claims 3-5, characterized in that the fiber preform is axially mechanically loaded during winding in order to tension the wound fibers. Method according to at least one of claims 3-6, characterized in that the fiber preform during winding or after winding is applied for mechanical stabilization with a stabilizing agent. Method according to at least one of claims 2-7, characterized in that the membrane ( 8th ) is drawn into the fiber preform. Method according to at least one of claims 2-8, characterized in that the fiber preform in the opened tool ( 9 ) and the tool ( 9 ) is closed. Method according to at least one of claims 2-9, characterized in that the tool ( 9 ) is rotated with the fiber preform at a predetermined minimum speed. Method according to at least one of claims 2-10, characterized in that the fiber preform is axially mechanically relieved during rotation in order to relax the wound fibers and to deposit the fiber preform on the tool surface ( 10 ). A method according to claim 11, characterized in that an air suction is generated by radial bores and negative pressure outside of the mold. A method according to claim 12, characterized in that the negative pressure through turbine blades ( 14 ), which on the outside of the rotating mold ( 9 ) and is in operative connection with a stationary housing, wherein the housing further turbine blades ( 15 ). Method according to at least one of claims 2 to 13, characterized in that the fiber preform is twisted during the depositing. Method according to at least one of claims 2 to 14, characterized in that the membrane is expanded by means of a tempered pressure medium. Method according to at least one of claims 2 to 15, characterized in that the mold space is evacuated by applying negative pressure. Method according to at least one of claims 2 to 16, characterized in that the tool ( 9 ) is tempered during injection and / or after injection of the plastic. Method according to at least one of claims 2 to 17, characterized in that the curing of the plastic is assisted by means of microwave radiation. Device for carrying out a method according to at least one of the preceding claims, comprising a rotatable winding device ( 1 ) with a rotation axis ( 5 ), one to the axis of rotation ( 5 ) concentrically arranged first ring ( 2 ), one to the axis of rotation ( 5 ) concentrically arranged and from the first ring ( 2 ) axially spaced second ring ( 3 ) and one between the rings ( 2 . 3 ) holding device ( 4 ) and a rotatable tool ( 9 ) with a rotation axis ( 5 ) and a radially inner tool surface ( 10 ) for delimiting a shape space ( 12 ). Device according to claim 19, characterized in that the first ring ( 2 ) and the second ring ( 3 ) are axially displaceable relative to each other. Device according to at least one of claims 17 to 21, characterized in that the molding space ( 12 ) using the first ring ( 2 ) and the second ring ( 3 ) is tightly closed. Device according to at least one of claims 17 to 21, characterized in that the first ring ( 2 ) and / or the second ring ( 3 ) at least one channel for evacuating the mold space ( 12 ) and / or for injecting a plastic.  A rotationally symmetrical fiber-plastic composite component having at least one axial undercut section produced by a method according to at least one of claims 1 to 18. Fiber-plastic composite component according to claim 23, characterized in that the component is a bellows spring for a chassis of a vehicle.

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