DE102011104071A1 - Method for manufacturing leaf spring that is utilized for function integration of e.g. axle to vehicle, involves melting matrix material in prepeg tape by concentrated introduction of heat when prepeg band is impinged on mold - Google Patents

Abstract

The method involves depositing a prepeg band (2) i.e. multi-layer fabric, in a specified mold, where the prepeg band comprises matrix material that comprises thermoplastic resin. The matrix material in the prepeg tape is melted by concentrated introduction of heat using laser radiation infrared light irradiation, ultrasound and/or microwaves when the prepeg band is impinged on the mold, where the mold is partially formed by tool parts of a molding tool. The prepeg band is formed into a base body of a leaf spring (1) using an injection-molded process.

Description

The invention relates to a method for producing a leaf spring according to the features of the preamble of claim 1 and a leaf spring according to the features of the preamble of claim 9.

From the prior art, as in the DE 10 2006 052 137 A1 described a method for producing leaf springs made of a fiber composite material. In the method, the top and the bottom of a strand of fibers, which consists of at least parallel aligned fibers, covered with at least one Abdeckmaterialbahn. The fibers of the fiber strand are wetted with a not yet set plastic matrix. The covered and plastic matrix occupied fiber strand is heated to impregnate the fibers of the fiber strand with the not yet set plastic matrix. The covered plastic matrix impregnated fiber strand is cooled. The covered plastic matrix-impregnated fiber strand is cut into individual prepregs or wound into a prepreg roll. Several layers of prepregs are laid vertically one above the other on a convexly curved surface to a raw leaf spring. The green leaf spring is cooled on a convexly curved surface and pressed in a press to a pressed raw leaf spring. The pressed raw leaf spring is heated and finished to the finished leaf spring. In all manufacturing steps, predetermined temperatures are set on the respective material or on the respective intermediate product and maintained for predetermined periods of time.

The invention has for its object to provide an improved method for producing a leaf spring and an improved leaf spring.

The object is achieved according gellst by a method for producing a leaf spring with the features of claim 1 and a leaf spring with the features of claim. 9

Advantageous embodiments of the invention are the subject of the dependent claims.

In a method for producing a leaf spring from a fiber composite material in the form of a prepreg strip, at least one prepreg strip comprising a matrix material made from a thermoplastic material is deposited on at least one predetermined shape, wherein the matrix material is melted by concentrated introduction of heat when hitting the mold ,

The term prepreg is known to mean a semifinished product or a precursor for the production of articles from a fiber composite material, which consists of continuous fibers and a plastic matrix. A prepreg strip is a prepreg in strip form, which for processing is usually in rolled-up form and can be correspondingly unrolled and processed from a prepreg strip roll.

For the method according to the invention very narrow prepreg tapes are preferably used, which are produced by longitudinal cutting of wide prepreg tapes, d. H. a wide prepreg tape is divided into a plurality of narrow prepreg tapes, also called prepreg tapes. These narrow Prepreg or Prepregbändchen be rolled up again and can then be used in the process according to the invention, preferably a plurality of such Prepregbändchenrollen are arranged on a creel, so that a plurality of these narrow prepreg or Prepregbändchen simultaneously parallel to each other from the Prepregbändchenrollen unroll and the given Form are to be filed.

The inventive method allows the production of very lightweight and inexpensive leaf springs made of thermoplastic fiber composite material, especially for use in vehicles. Due to a weight saving achieved by the use of such lightweight leaf springs in vehicles, a fuel and energy consumption and pollutant emissions of the vehicles are reduced, especially compared to the use of leaf springs made of metal.

In addition, the leaf springs produced by the method have smaller dimensions, d. H. a smaller volume, on, whereby a space required for the leaf spring on the vehicle space is reduced. Furthermore, the leaf springs have improved media and chemical resistance, so that no or a much lower corrosion protection is required and a longer life of the leaf springs is achieved.

A spring characteristic of the respective leaf spring to be produced can be influenced by a laminate structure of the leaf spring which is adapted to the respective requirements, for example by a number of laid layers of the prepreg strip and by a composition of the prepreg strip. In this way, a damping behavior of the leaf spring is improved, whereby an increased ride comfort of the vehicle is achieved.

Compared to known from the prior art manufacturing method using A fiber composite material with a matrix of a thermosetting plastic results in the inventive method has the advantage that the prepreg with the matrix of thermoplastic material can be stored almost indefinitely at room temperature. In addition, no use of solvents for leaf spring production is required. Furthermore, a recycling of the leaf spring produced by the method is possible. In addition, the thermoplastic material for the matrix is available as granules, so that even a simple and cost-effective production of prepreg tapes is already possible.

Also compared to known from the prior art manufacturing method using a fiber composite material with a matrix of thermoplastic material and to manufacturing processes in which the prepregs, with thermoplastic or thermosetting matrix, stacked in a mold and then pressed under the action of pressure and heat are obtained by the inventive method advantages, since no compression under pressure and heat is required in the process according to the invention. In this way, the method according to the invention results in a short cycle time and low investment costs, since the method enables a shorter production time and a production system for carrying out the method is more flexible. Furthermore, the method allows a simple way to produce leaf springs with different geometric shapes, since the geometry of the leaf springs produced by the method is not tool-bound, d. H. There are no different, adapted to the particular shape tools required for different geometric shapes, so that eliminates tool costs for the production of such tools.

In addition, in the process no depositing of multiple layers of prepregs vertically one above the other is required, but it can be a continuous production of the leaf spring by a continuous unwinding and placing the prepreg in a winding process. Furthermore, the leaf spring or a main body of the leaf spring is finished after cooling, so that no subsequent compression under the action of pressure and heat is required, which would require a complicated setting and monitoring of material-dependent temperature and pressure gradients.

Embodiments of the invention are explained in more detail below with reference to drawings.

Showing:

1 schematically a perspective view of a leaf spring,

2 schematically a leaf spring in side view,

3 schematically applying a prepreg tape to a mold,

4 schematically a depositor of a leaf spring,

5 schematically an insert clamped in holders,

6 schematically a first embodiment of a method for producing a leaf spring,

7 1 is a schematic view of a detail of a leaf spring produced by a first embodiment of the method;

8th 1 schematically shows a molding tool comprising two mold parts, and two inserts of a leaf spring,

9 schematically a leaf spring produced by a second embodiment of a manufacturing method,

10A to 10F a method sequence of a second embodiment of a method for producing a leaf spring,

11A to 11D a process flow of a second embodiment of a method for producing a leaf spring in detail view,

12 schematically a layer structure of a leaf spring,

13 schematically a leaf spring, produced by a first embodiment of a manufacturing process, after an injection molding process and

14 schematically a leaf spring produced by a second embodiment of a manufacturing process, after an injection molding process.

Corresponding parts are provided in all figures with the same reference numerals.

The 1 and 2 show schematically a leaf spring 1 for a vehicle, which by means of a method for their production from a prepreg strip 2 trained fiber composite material can be produced. The leaf spring 1 has a main sheet 1.1 on, which by endless deposited layers of prepreg tapes 2 ie by one or more endless prepreg tapes 2 was produced.

The term prepreg is known to mean a semifinished product or a precursor for the production of articles from a fiber composite material, which consists of continuous fibers, ie of reinforcing fibers, and a plastic matrix. A prepreg tape 2 is a prepreg in belt form, which is for processing mostly in rolled form and can be unrolled and processed accordingly from a prepreg roll.

For the method explained in more detail below, very narrow prepreg tapes are preferred 2 used, which are produced by longitudinal cutting of wide prepreg tapes, ie a wide prepreg tape is in a plurality of narrow prepreg tapes 2 , also known as Prepregbändchen, parts. These narrow prepreg bands 2 or prepreg tapes are rolled up again and can then be used for the process.

In addition to the main sheet 1.1 has the embodiment of the leaf spring shown here 1 even more leaves 1.2 on, which in the form of further strips of fiber-reinforced plastic, for example, further prepreg tapes, according to a required spring characteristic of the leaf spring 1 welded locally. These other leaves 1.2 in particular their number and training is optional; Of course, there are also leaf springs 1 can be produced, which only the main sheet 1.1 exhibit.

The leaf spring 1 also has a bolt at both ends 3 on, preferably of metal. About these bolts 3 can the leaf spring 1 be mounted on the vehicle, where it is usually with one end in a fixed bearing and the other end in a floating bearing, also referred to as a spring rocker stored.

The leaf spring 1 is, as will be explained in more detail below with reference to the further figures, preferably produced by means of UD tape laying, ie by means of prepreg tapes 2 in which the reinforcing fibers are unidirectionally aligned. As a material prepreg tapes 2 made of reinforcing fibers and a matrix of a thermoplastic used. The reinforcing fibers are, for example, carbon fibers, also called carbon fibers, aramid fibers, metal fibers, or metal wires or glass fibers. The thermoplastic material is for example a polyamide, in particular polyphthalamide (PPA) or polyamide 6 (PA 6).

If the reinforcing fibers are deposited, for example, in network structures, they act in the event of a crash to ensure the structural integrity of the component.

For functional integration of other components, for example, for receiving an axle of the vehicle, so from wheelset or axle bearings, cables and wires, the leaf spring 1 More precisely, a base body of the leaf spring formed by the UD tape laying 1 additionally be encapsulated with a plastic matrix of a high short fiber filled plastic. Hochkurzfasergefüllt means that the plastic matrix has a high proportion of short fibers, for example carbon fibers or glass fibers.

For encapsulation with the plastic matrix, an injection molding process is preferably used, in particular a two-component injection molding process. By using it can also rubber inserts of leaf spring bearings including inserted connection elements of the leaf springs 1 , for example the bolt 3 , be integrated, ie injected and then post-cured or at the same time the rubber material.

The main body of the leaf spring 1 is made of a fiber composite material with thermoplastic matrix. These are thermoplastic prepreg bands 2 used, which of a creel not shown here on at least one predetermined shape 4 be filed as in 3 shown.

By concentrated heat input, preferred as in 3 represented by means of laser irradiation, alternatively or additionally by means of infrared light irradiation, by means of ultrasound and / or by means of microwaves, the matrix material of the prepreg bands 2 when hitting the form 4 melted. Ie. in the example shown here will be one or more lasers 5 on a respective application region of the prepreg strip 2 on the mold 4 directed. In this way, the reinforcing fibers are optimally embedded in the plastic matrix and, moreover, the prepreg tapes are welded together 2 , A storage device consists of one or more staggered pressure rollers 6 which are along the shape 4 to be moved, the prepreg bands 2 with a predetermined pressure force F to the mold 4 Press on and consolidate the prepreg bands 2 to ensure.

In a first embodiment of the method, the prepreg tapes become 2 around one in 4 illustrated depositors 7 stored around, with the depositor 7 for this embodiment of the method of two cylindrical bushings 7.1 , preferably of metal, a longitudinal element 7.2 which is in the Essentially the form 4 forms, as well as two triangular filling parts 7.3 is formed, as in the 5 to 7 shown. The longitudinal element 7.2 is about the filling parts 7.3 with the jacks 7.1 connected.

The longitudinal element 7.2 is formed, for example, of organofilms, ie of at least one fiber composite material, or of a fabric or scrim or of metal in the form of a metal sheet. The filling parts 7.3 are preferably made of plastic or metal. The depositor 7 remains in the leaf spring 1 ,

During the procedure, the depositor 7 in the two sockets 7.1 on appropriate brackets 8th stored as in 5 shown, and with the prepreg bands 2 wrapped as in 6 shown. Ie. the storage device is particularly in the longitudinal direction of the insert 7 wrapped around this, with the prepreg bands 2 first on the depositor 7 and in further layers on already applied prepreg tapes 2 are stored and during the deposition by targeted introduction of heat and pressing by means of the pressure roller 6 be merged with each other.

It is, especially if the depositor 7 Metal, particularly advantageous when directly on the insert 7 first at least one layer with prepreg tapes 2 is applied, which have glass fibers as reinforcing fibers, so that the insert 7 is completely covered by these, and only on these layers more layers of prepreg tapes 2 be applied, which have carbon fibers as reinforcing fibers. In this way it prevents metal parts of the insert 7 and the prepreg tapes 2 , which have carbon fibers, touch. This is particularly advantageous for reasons of corrosion protection, as will be explained in more detail below.

To a different orientation of different layers of prepreg tapes 2 To achieve the storage device can also be guided in other directions, for example transversely to the longitudinal direction of the insert 7 or obliquely to the longitudinal direction of the insert 7 , In this way, a creeping and thus very stable layer structure is made possible, as will be explained in more detail below. By means of this first embodiment of the method, the in 7 Leaf spring shown in detail 1 or first of their basic body, which can be further processed, formed.

In a second embodiment of the method, only two sockets are used 7.1 as depositor 7 , An outer contour of these sockets 7.1 is formed from a semicircle and two radii tapering towards each other, as in 8th and more detailed in 9 shown. Ie. the jacks 7.1 each have in the longitudinal direction of the leaf spring 1 tapered formations 7.1.1 on, which are similar to the filling parts 7.3 of the depositor 7 to carry out the first embodiment of the method and the outer contour of a smooth transition from a thin central region of the leaf spring 1 on the jacks 7.1 forms. In this way, the prepreg bands can 2 in the laying process in a kink-free flowing transition from the middle area to the bushings 7.1 be moved. The prepreg bands 2 be around these jacks 7.1 stored around which, for this embodiment of the method, the depositor 7 form and in the leaf spring 1 remain as in 9 shown.

In the following, the second embodiment of the method will be described with reference to FIG 10A to 10F and 11A to 11D explained in a detailed representation. The first layers of prepreg tapes 2 be in the middle area of the leaf spring 1 over two already in 8th illustrated mold parts 9 . 10 filed a mold. A surface of the mold parts 9 . 10 each forms a mold half of the mold 4 for storing the prepreg tapes 2 ,

The production of the leaf spring 1 starts in this embodiment of the method as in 10A and 10B shown on one of the sockets 7.1 with the laying down of the first layer prepreg tapes 2 , the heat supply and the pressing by means of the pressure roller 6 , The prepreg bands 2 be first on the outer contour of this socket 7.1 and their shape 7.1.1 filed, which tangent continuous in a contour of the surface of the first mold part 9 passes. This application of prepreg tapes 2 then sits down on the first mold part 9 , wherein the storage device with the pressure roller 6 the first mold part 9 leaves, as in 10C and detailed in 11A shown. At the end of the first mold part 9 become the prepreg bands 2 as in 10D shown on the other socket 7.1 applied, the outer contour also on their shape 7.1.1 tangent-continuous in the contour of the surface of the first mold part 9 passes. While the pinch roller 6 over this socket 7.1 rolls, becomes the second mold part 10 to the first layer of prepreg tapes 2 moved up. This first layer of prepreg tapes 2 will now be from the second mold part 10 and from the first mold part 9 supported.

In the next step, the first mold part becomes 9 gone and the prepreg bands 2 be on the already deposited part of the first layer prepreg tapes 2 stored, heated and by means of the pressure roller 6 pressed, wherein the second mold part 10 form 4 , more precisely the Form half of the mold 4 pretends as in 10E and detailed in 11B shown.

Because the prepreg tapes 2 in particular during the deposition of the first layers on the mold parts 9 . 10 not yet fully cured, they could from the respective mold part 9 . 10 to solve. To prevent this, are vacuum cleaners 11 , also referred to as vacuum suction, in the mold parts 9 . 10 integrated. These suck the prepreg bands 2 to the mold parts 9 . 10 at. To support can still a pressing element 12 be used. For this example, a hose made of an elastomeric rubber or a chain-shaped pressure element 12 used as in 10F shown. It is also possible to use a segmented mold having a plurality of individually adjustable parallel zueinender arranged slide. The variable depth of the individual slides allows the topography of the component to be precisely adjusted.

After the described steps have been carried out repeatedly, to some layers of prepreg tapes 2 were stored, owns the leaf spring 1 , More precisely, their forming body, due to the already stored layers of prepreg tapes 2 sufficient rigidity and support by the mold parts 9 . 10 and the pressing element 12 is no longer necessary. Now, one of the pinch roller 6 counteracting force by counter-pressure rollers 13 be generated as in 11C and 11D shown. These counter-pressure rollers 13 run the middle region of the leaf spring to be formed 1 from. You are always on the pressure roller 6 opposite side.

Also in this second embodiment of the method is, in particular when the jacks 7.1 , which here the depositor 7 form, metal, particularly advantageous when the first layer or a plurality of first layers Prepregbänder 2 Having glass fibers as reinforcing fibers, and only on these layers more layers of prepreg tapes 2 be applied, which have carbon fibers as reinforcing fibers. In this way, as already described, prevents metal parts of the insert 7 and the prepreg bands 2 , which have carbon fibers, touch. This is, as already mentioned, for reasons of corrosion protection particularly advantageous.

Also in this second embodiment of the method can be to a different orientation of different layers of prepreg tapes 2 to reach the storage device are also performed in other directions, for example, transversely to the longitudinal direction of the forming leaf spring 1 or obliquely to the longitudinal direction of the forming leaf spring 1 , This can be done as soon as the two mold parts 9 . 10 for supporting the layers of prepreg tapes 2 are no longer necessary, so that the storage device also obliquely or transversely to the longitudinal direction around the forming leaf spring 1 can be led around. In this way, a creeping and thus very stable layer structure is made possible, as will be explained in more detail below.

As a result of the described method sequence of the two embodiments of the method, in each case a composite component is produced which, after cooling, is a finished leaf spring 1 is usable or which as the main body of the leaf spring 1 placed in an injection mold and molded around the functional integration or in which in the two-component injection molding elastic bearings, as a rubber bearing 14 designated, for example, from at least one thermoplastic elastomer (TPE), for example, urethane-based (TPU) are injected. Likewise, a rubber, possibly parallel to it, poured, vulcanized and postcrosslinked.

By means of UD tape laying, ie by laying prepreg tapes 2 With unidirectionally oriented reinforcing fibers, the orientation of the prepreg bands can be adjusted 2 choose freely, which allows variable fiber angle combinations. Furthermore, various prepreg tapes 2 with different characteristics, resulting from the choice of reinforcing fibers, ie a fiber content and a fiber material, and the matrix material are stored creeping. This is also a thickness of the leaf spring 1 selectable. In addition, the prepreg bands 2 over the full width or only over a portion of the width of the leaf spring 1 be filed. In this way, a desired spring characteristic can be set, provide integrity for the crash structure, meet the space requirements and determine the storage quality.

As the material, as already mentioned, preferably prepreg tapes 2 of reinforcing fibers, for example of carbon fibers, aramid fibers, steel wires and / or glass fibers, and a thermoplastic matrix, for example of at least one polyamide used, in particular polyphthalamide (PPA) or polyamide 6 (PA6). The narrow prepreg bands 2 Also referred to as Prepregbändchen, which are preferably cut out of wider prepreg tapes, for example, have a width of about 6.35 mm and a thickness of about 0.1 to 0.5 mm. If carbon fibers are used as reinforcing fibers, then their volume fraction is in the prepreg bands 2 preferably about 50%. Ie. the volume fraction of the matrix material, for example a polyamide, in particular of polyphthalamide (PPA) is then about 50%. A glass transition temperature of polyphthalamide (PPA) is higher than 125 ° C. Furthermore, polyphthalamide (PPA) has almost constant mechanical properties over the operating temperature of -40 ° C to 120 ° C.

In 12 schematically is a layer structure of the manufacturable by the method leaf spring 1 shown, with the leaf spring 1 is shown in plan view. The layers of prepreg tapes only shown in sections A1, A2, A3 2 each extend preferably over the entire length and width of the leaf spring 1 , In the example shown here, only a section of a first layer A1, a section of a second layer A2 and a section of a third layer A3 of prepreg strips are shown 2 shown.

The layer structure shown here can be realized in particular by means of the first embodiment of the method, in which also already the first layers of prepreg strips 2 transverse or oblique to the longitudinal direction of the leaf spring 1 can be laid. With the second embodiment of the method, a slightly different layer structure is expedient, since here at least the first layers of prepreg strips 2 in which a support by the mold parts 9 . 10 is required, in the longitudinal direction of the leaf spring 1 should be moved. Ie. in particular by means of the second embodiment of the method which are oblique to the longitudinal direction of the leaf spring 1 aligned layers of prepreg tapes 2 preferably only laid when the leaf spring 1 already has a sufficient number of layers to be sufficiently stiff, so that the mold parts 9 . 10 are no longer necessary.

The prepreg bands 2 are creeping, stored as Gelegeaufbauten with several layers. The leaf spring 1 In this example, it has one or more layers in the longitudinal direction of the leaf spring 1 laid prepreg tapes 2 and one or more layers oblique to the longitudinal direction of the leaf spring 1 laid layers of prepreg tapes 2 on, with these layers with obliquely laid prepreg tapes 2 , as in 12 represented, may have a different orientation.

Since the thermoplastic matrix consists of entangled molecular chains, they slide or entknäulen under external stress, resulting in an elongation. In contrast, the carbon fibers have almost no creep properties. Therefore, creep does not occur along the reinforcing fibers but across the laying direction of the prepreg tapes 2 on. The creeping layer structure has favorable force redistribution and hinders lateral contractions, since the main force flow is introduced via the reinforcing fibers and the transmission of force by matrix bridges is avoided. Furthermore, the high number of supporting layers reduces creep.

Alternatively to the layer structure shown here by laying unidirectional prepreg strips 2 in different directions, for example, prepreg bands 2 be laid in which the reinforcing fibers are not arranged unidirectionally, but for example as a scrim, or tissue. In this way, all Prepregbänder 2 in the longitudinal direction of the leaf spring 1 be laid, which is particularly advantageous for the second embodiment of the method. This also makes it possible to achieve a creeping layer structure.

A functional integration of other components in the leaf spring is possible by injection molding. In this case, after molding and consolidation, the encapsulation of the main body of the leaf spring 1 , For this purpose, the base body is inserted via a handling device into an injection molding tool, in particular an injection molding press. The handling device may be, for example, a multiple robot. The injection mold is closed and overmolded with a high short glass filled, easily flowing thermoplastic to enable functional integration.

Due to the good geometric design and the material connection between the inserted into the injection mold base body and the overmolded material during the injection molding process, the functional integration of attachments, a recording of the axle, so Radsatz- or axle bearings, and cables and lines is very cost effective to implement. By using the two-component injection molding process, the rubber bearings can also be used 14 the leaf spring 1 including inserted connection elements of the leaf spring 1 , for example the bolt 3 and between the bolts 3 and the rubber bearings 14 arranged metal bushes 15 For example, made of stainless steel with an aluminum coating or Aluminiumlegierug be integrated into the body, as in the 13 and 14 shown, where 13 the leaf spring 1 with the base body produced in the first embodiment of the method and 14 the leaf spring 1 with the base body produced in the second embodiment of the method shows.

For this purpose, the main body and the bolts 3 and optionally in addition the metal bushes 15 placed in the two-component injection molding tool and overmoulded, preferably with an injection-moldable thermoplastic elastomer (TPE), for example based on urethane (TPU). In this way, no expensive chemical vulcanization process is required. In addition, the injection molding process can or deconsolidation of the fiber composite plastic area of the leaf spring 1 respectively. However, the alternative possibility of vulcanization is still available, ie it can, alternatively to the injection molding, the main body of the leaf spring 1 and the bolts 3 , if necessary, with the metal bushings 15 be placed in a vulcanizing tool.

In a carbon fiber composite plastic-metal construction, as already mentioned, protective measures against contact corrosion must be taken. This contact corrosion, also known as bimetallic corrosion, is a special form of galvanic corrosion. In galvanic corrosion, different galvanic potentials between a carbon fiber composite plastic component and a metal component, in cooperation with an electrolyte such as condensation or normal humidity, cause corrosion. Therefore, appropriate protective measures must be taken to separate the carbon fiber composite plastic components and metal components from each other so that they do not directly contact each other.

This is the leaf spring 1 as already mentioned, preferably prepared so that the prepreg tapes 2 which are in contact with metals, have glass fibers instead of carbon fibers as reinforcing fibers. Ie. in the two embodiments of the method, they are applied directly to the depositor (s) 7 first prepreg tapes 2 laid with glass fibers as reinforcing fibers and then only prepreg tapes 2 with carbon fibers as reinforcing fiber, so prevent these separation layers of prepreg tapes 2 with glass fibers as reinforcing fibers the contact between metal and the carbon fibers and thus a possible corrosion.

LIST OF REFERENCE NUMBERS

1

leaf spring

1.1

main sheet

1.2

another sheet

2

prepreg

3

bolt

4

shape

5

laser

6

pinch

7

depositors

7.1

Rifle

7.1.1

formation

7.2

longitudinal member

7.3

filling

8th

bracket

9

first mold part

10

second mold part

11

Suckers

12

pressing element

13

Counter-pressure roller

14

Rubber bearing

15

metal bushing

A1

Detail of a first layer

A2

Detail of a second layer

A3

Section of a third layer

F

pressure force

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 102006052137 A1 [0002]

Claims (9)

Method for producing a leaf spring ( 1 ) from a prepreg tape ( 2 ) formed fiber composite material, characterized in that at least one prepreg strip ( 2 ), which has a matrix material made of a thermoplastic material, to at least one predetermined shape (US Pat. 4 ) is deposited, wherein the matrix material by concentrated introduction of heat when hitting the mold ( 4 ) is melted. A method according to claim 1, characterized in that the heat is introduced by laser irradiation, by infrared light irradiation, by means of ultrasound and / or by means of microwaves concentrated in the matrix material. Method according to claim 1 or 2, characterized in that the at least one prepreg strip ( 2 ) in several layers on the mold ( 4 ) is deposited, wherein the matrix material by concentrated introduction of heat when hitting one already on the mold ( 4 ) deposited layer is melted. Method according to one of claims 1 to 3, characterized in that the shape ( 4 ) for depositing the at least one prepreg strip ( 2 ) at least partially by at least one depositor ( 7 ) is formed, which by means of at least one prepreg strip ( 2 ) and in the leaf spring ( 1 ) remains. Method according to one of the preceding claims, characterized in that the shape ( 4 ) for depositing the at least one prepreg strip ( 2 ) at least partially by at least one mold part ( 9 . 10 ) is formed at least one mold. Method according to one of the preceding claims, characterized in that a means of the at least one prepreg strip ( 2 ) formed body of the leaf spring ( 1 ) is at least partially encapsulated by means of at least one plastic. A method according to claim 6, characterized in that the main body of the leaf spring ( 1 ) is at least partially encapsulated by injection molding and optionally postcrosslinked or consolidated. A method according to claim 6 or 7, characterized in that at least one further component on the base body of the leaf spring (14) by the molding with plastic. 1 ) is arranged. Leaf spring ( 1 ) prepared by a method according to any one of claims 1 to 8.

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