WO2015040050A1

WO2015040050A1 - Method for winding fiber composite components

Info

Publication number: WO2015040050A1
Application number: PCT/EP2014/069782
Authority: WO
Inventors: Peter Fassbaender
Original assignee: F&G Engineering Gmbh
Priority date: 2013-09-17
Filing date: 2014-09-17
Publication date: 2015-03-26
Also published as: EP3046751A1; DE102014217215A1

Abstract

The invention relates to a method which allows winding three-dimensional structural components from fiber material threads that have been impregnated with liquid resin.

Description

Method for winding fiber composite components

Fiber composite components are very resilient despite their low weight. Here are a variety of fibers, such. As glass fibers, carbon fibers and others are used, which are impregnated with resin and then pressed in a mold.

This process is relatively expensive because it requires an expensive mold that specifies all surfaces of the later workpiece exactly. In addition, the mold cavities have a relatively large volume, which is filled with fibers and liquid resin, and are therefore even heavier than necessary. Also, the manufacturing cost of such fiber composite components are relatively high.

The invention has for its object to provide components made of fiber composites, which - in terms of load capacity - are even easier and their production is still inexpensive and largely automated.

This object is achieved according to the invention by a framework made of a fiber composite tool comprising a plurality of bars and a plurality of nodes, wherein the bars consist of one or more threads impregnated with a resin or a thermoplastic (eg PA66).

A thread in the context of the invention is a strand of many substantially mutually parallel fibers, either of the same fibers, such as. As carbon fibers, or mixtures of different fibers are formed. Fibers made of a thermoplastic (e.g., PA 66) may also be included. Then it is possible to process the threads dry and after the threads are laid, to heat the precursor to such an extent that the fibers melt from thermoplastic material, wherein all the fibers are bonded together to form the strand.

The threads may, for example, have a diameter of one to three millimeters. Such threads are commercially available and can be obtained in various qualities on the market.

Before processing, the threads are soaked with a resin that is still liquid at this time. Alternatively, the threads can also be wound dry and then the resin can be applied.

It may, for example, but not limited thereto, epoxy resin are used. For example, it is possible to pass the thread through a bath of resin, so that the thread is impregnated with this resin.

According to the invention it is now provided that the threads (after curing of the resin) form bars of a truss, which connect the nodes of the truss with each other. By the way in which the at least one thread connects the knots together, the cross-section of the bars can be determined in a simple manner and thus the tensile and compressive strength of the bars can be adapted to the loads corresponding to operation. When the loads are high, the thread is stretched several times between the affected nodes. The sum of the threads present between the nodes results after curing a rod of the framework according to the invention.

It is also possible and advantageous to guide the thread (s) between the nodes or around the nodes in such a way that they at least partially wrap around the nodes in such a way that the threads extend in the direction or coaxially with the force vectors occurring later during operation. Then it is ensured that the bars of the framework according to the invention are essentially loaded only on train and pressure and thus the fibers can fully exploit their performance.

The framework of the invention is extremely light and at the same time very high load capacity. Because no expensive mold is needed, but only the threads between different nodes must be braced, the tool costs are relatively low.

It is also possible, with the aid of tools or manufacturing devices having movable slides and / or forming components, to produce workpieces having trusses with bi- or three-dimensionally curved bars. This creates a whole new field of application.

In order to screw the framework of the invention with another component or connect in other ways, it is provided that in each case one or more of the nodes, a sleeve, preferably a sleeve made of metal or plastic, is arranged, and that the sleeve with a or more threads is wrapped. This is a very good power transmission from the sleeves, or the node in the bars and back possible. This organic and kink-free power transmission prevents the failure of individual bars and results in a very efficient framework.

It is of course also possible that a knot is looped by several threads. This allows a particularly good introduction of force, also from different directions, in these nodes.

Alternatively, a node can also be formed by interlacing a plurality of threads or by looping around each other.

If the framework has functional surfaces, e.g. has the tooth of a chainring, this functional surface is formed by one or more threads. A particularly resilient and wear-resistant design of the functional surfaces arises when the threads are parallel to a surface of the functional surface.

The object mentioned above is also achieved by a method according to one of claims 7 to 10.

Further advantages and advantageous embodiments of the invention can be taken in the following drawing, the description and the claims. All features disclosed in the drawing, the description and the claims can be essential to the invention both individually and in any combination with one another.

In the figures, the method according to the invention will be explained by way of example in a first exemplary embodiment using the example of a chainring of a bicycle.

Of course, the method is not limited to essentially two-dimensional chainrings, but it can also be used for the production of three-dimensional trusses for a variety of applications, be it from the automotive industry, for industrial robots or for everyday use.

Hereinafter, exemplary embodiments of the invention will be explained by way of example with reference to FIGS. Show it:

Figure 1 shows a holding device for producing a chainring for a bicycle from a framework of fiber composites;

Fig. 2-10 different steps in the production of the chainring in a plan view of the holding device;

11 + 12 different steps in the manufacture of the chainring in a side view of the holding device;

FIG. 13 shows the finished chainring;

14-16 different steps in the production of a high table from the framework of fiber composites in a perspective view of a holding device for the preparation of the bar table;

17 shows the finished bar table with the holding device;

FIG. 18 shows the finished bar table with the holding device removed;

19-23 different steps in the production of a fastening for torque-connection means of a propeller shaft from the framework of fiber composites in a perspective view;

Figure 24 shows a holding device in the manufacture of a base frame for a clamp for attaching a pipe from the framework of fiber composites;

25-27 different steps in the manufacture of the clamp on the holding device of Figure 24;

FIG. 28 shows a working step for fastening the base frame of FIG. 24 to the clamp of FIGS. 25-27 on the holder device of FIGS. 24-27;

FIG. 29 shows the ready-made clamp with basic frame on the holding device of FIGS. 24-28;

Figure 30 shows the finished clamp with base frame in a plan view and two side views; and

Figure 31 shows the finished clamp with base frame in a perspective view.

Description of the embodiments

1 shows a top view of a holding device 1 for producing a chainring 17 for a bicycle from a framework made of fiber composite materials in a first exemplary embodiment. The holding device 1 comprises a base plate 3 on which a plurality of shaped bodies 5 and a plurality of sleeves 7 are arranged. The sleeves 7 are exemplarily pushed onto five on a circular path of the base plate 3 correspondingly arranged pin 6. The sleeves 7 are, for example, made of metal and later serve to screw the finished chainring 17 with the crank of a bicycle, which also has five holes on the same pitch circle diameter. Because the necessary screws not shown generate significant local pressure forces, it is advantageous in this application to produce the sleeves 7 made of metal.

The molded bodies 5 are likewise designed as pins, which are fastened on the base plate 3. The radially inwardly oriented semicircles of the molded bodies 5 predetermine the shape of the later teeth 16 of the chainring 17 (= functional surfaces 11). A tip diameter D _head is also shown in FIG.

Outside the molded body 5 more deflection aids 9 are arranged. These deflection aids 9, like the shaped bodies 5, remain on the base plate 3 and serve to deflect and align the resin-impregnated threads with the aid of which a truss-like chainring 17 is produced.

The further figures show now in several steps the inventive method, which consists in short, one or more and usually resin impregnated threads so to wrap around the sleeves 7, the moldings 5 and / or the deflection aids 9 and / or to loop, that a truss-like chainring 17 is formed.

In this case, all functional surfaces 11 must be looped around at least by a resin-impregnated thread 13, so that, as a result, the fibers of the thread run parallel to the surface of the resin-impregnated thread. The sleeves 7 must be wrapped by one or more threads, so that the power transmission between the sleeve 7 (= knot of the framework) and the rods formed from the wound threads of the truss is guaranteed.

The impregnated in resin thread is indicated in the figures by the reference numeral 13.

In the lower part of Figure 1, a sleeve 7 and a molded body 5 are shown enlarged. The part of the molded body 5 which lies radially within the tip diameter D _head gives the later functional surface (tooth of the chainring 17) the desired shape and is therefore also designated as a forming surface 11.

In thus produced teeth 16 of the chainring 17, the members of a bicycle chain engage in a conventional manner.

As is apparent from the figures shown below, the later chainring 17 is wound from one or more threads in several levels one above the other until the desired cross section of the later bars of the framework is reached.

Each thread is always between a sleeve 7, which represents a node in the sense of the framework of the invention, and a molded body 5 with its functional surface 11, which also represents a node in the sense of the framework of the invention, tensioned. The threads are according to the invention wound so that the directions of the threads are coaxial with the force vectors occurring later during operation. This can be ensured in an optimal manner that the bars of the framework, which are formed by just stretched pieces of thread, only to train or pressure and thus material-appropriate burden.

With the first thread 13 according to Figure 5, the sleeves 7 are connected to the moldings 5.

In FIGS. 2, 3 and 4 it becomes clear how the shaped bodies 5 are looped around with a further thread 15 in such a way that very strong teeth and tooth tips result. In the area of the functional surfaces 11 (see FIG. 1), the threads 15 run parallel to the shaped bodies 5, so that an optimal introduction of force is ensured here as well.

The following figures show various stages of winding

threads

13 and 15 around the sleeves 7, the molded bodies 5 and the deflection aids 9.

After this winding is completed and the resin-impregnated

threads

13, 15 are in sufficient numbers at the desired locations, all threads are pressed from above by a corresponding counter-plate (not shown) to the base plate 3 down. As a result, the threads are pressed together so that they give a very stable rod of a framework of the chainring 17 after curing of the thread.

FIG. 11 shows a side view of the device according to the invention. In this side view is also good to see that, first, the

threads

13 and 15 are wound in various levels quasi-building on the base plate 3 and there are also the outer deflection aids 9 can be seen.

If the truss is cured in the apparatus, it is removed from this and the radially outward beyond the tip diameter D _head protruding parts are cut or milled away. This can be done for example by means of a milling cutter, which is guided along the tip circle diameter D _head . The magnification shown in Figure 8 above shows the thus prepared teeth 16 of the chainring 17 in detail.

In Figure 13, an inventive chainring 17 can be seen. Because of the available in the rear wheel freewheel, transmits a bicycle chainring 17 torques in one direction only. Good to see in the representation of the chainring 17 according to the invention, that the rods between the sleeves 7 and the ring gear are rotationally dependent, so that an optimal ratio of weight and load capacity is realized. The shown prototype with 53 teeth has a weight of less than 40 g!

In a second embodiment, a (bistro) bar table 21 is made from the framework according to the invention made of fiber composite material. Figure 18 shows the bar table 21 without bottom and top plate.

FIG. 14 shows a device 1 for the production of the bar table 21. The device 1 comprises two circular base plates 25, around each of which a segmented base plate cover ring 23 is arranged. The base plate cover rings 23 carry a plurality of deflection aids 9.

The base plates 25 take the positions of a bottom surface and a top surface of the high table 21 with the respective base plate shrouds 23 during manufacture. Both base plates 25 may have different diameters. The diameter size may, for example, be about 35 to 40 cm.

The two base plates 25 are preferably arranged spaced from each other by a centrally arranged (square) tube 29 and positioned relative to each other. The length of the square tube 29 substantially determines the later height (e.g., 1.20 m) of the bar table 21. The square tube 29 can penetrate the base plates 25 and protrude on both sides of the holding device 1. Of course, the square tube 29 may also have a round cross-section.

The base plates 25 may have stiffening elements 27 to increase their stability, wherein, for example, four stiffening elements 27 are arranged perpendicular to the outside on the base plate 25 and on the square tube 29 at a right angle to each other. In addition, the base plates 25 may be pierced by openings 26.

The base plate cover rings 23 have in the circumferential direction on a plurality of deflection aids 9, which may be formed as a bolt. The deflection aids 9 may have a protruding edge at the free end. The deflecting aids 9 serve to wind one or more resin-impregnated threads 13 around the deflecting aids 9 and / or to loop that a truss-like rotational hyperboloid is created between the base plates 25.

The deflection aids 9 form at least partially the nodes of the framework and serve as attachment points for a table top and a base plate (not shown). Of course, several threads 13 can be stretched in a composite of a deflection aid 9 to the other deflection aid 9. The threads 13 or the combination of threads result after curing rods of a very stable framework. FIG. 17 shows the finished truss directly after production on the holding device 1.

FIGS. 14, 15 and 16 show a yarn course at three different points in time in a first production phase of the bar table 21. At the top right in FIGS. 14 to 16 only the thread course is shown. The threads 13 are preferably not stretched parallel to the square tube 29, but at an angle, so rather biased diagonally. As a result, a waist 31 (= Rotationshyperboloid) of the bar table 21 is automatically generated, as illustrated in Figures 17 and 18. By the diagonal bracing of the threads 13 automatically form points at which the threads 13 intersect. These crossing points also represent nodes in the framework.

If the production thus described is completed and the resin cured, the holding device 1 is removed from the bar table (truss). The bar table 21 thus produced has a very low overall weight due to the low and optimum use of material and nevertheless a high mechanical load capacity.

In a third exemplary embodiment, a cardan shaft 33 is produced from the framework according to the invention made of fiber composite material. Like any commercially available cardan shaft, the propeller shaft 33 according to the invention also has connection means for transmitting torque at its ends. These connection means may be formed a flange plate 37 and / or a splined hub 39 or shaft. These connection means are also in the propshaft 33 according to the invention made of metal.

In between is in the propeller shaft 33 according to the invention, a tube 35, preferably arranged from a fiber composite material, for example with fibers of carbon, basalt or glass.

FIG. 19 shows such a propeller shaft 33 during manufacture. On the tube 35 of the propeller shaft 33 connecting means are arranged on both sides, e.g. a flange 37 and a shaft end 39, wherein the shaft end 39 may, for example, be formed as a splined hub (not visible in FIG. 19). Because of the high mechanical loads, the connection means 37, 39 are preferably made of metal.

The flange 37 has bores 41 which are used to screw the cardan shaft, e.g. to a gearbox, serve. In the holes 41 sleeves 43, 43 'are arranged, wherein the sleeves 41 have a distance from the drive flange 37 and protruding edge; similar to the previously described deflection aids 9 of the first embodiment.

The drive shaft 39 has in the circumferential direction a plurality of deflection aids 9, which are formed like a bolt. The deflection aids or elements 9 may have a protruding edge at the free end.

On the thus formed flange 37, one or more resin-impregnated threads 13 are first hung on the sleeve 43 'and wrapped or looped around the tube 35 to the deflection aids 9 as shown in Figures 19 and 20. In the figures 19 to 23, only the respective thread profile is shown in each case in the upper part of the figures.

The process illustrated in FIGS. 19 and 20 is then repeated with the remaining sleeves 43 and the remaining deflection aids 9 according to FIG. 21 until a multiplicity of threads 13 looped around the tube 35 are present.

Subsequently, the threads 13 are wound or looped around the tube 35 in the opposite direction and hooked onto the sleeves 43 of the drive flange 37 and the deflection aids 9 of the drive shaft 39, so that around the tube 35 according to Figures 22 and 23, a framework-like frame made of resin impregnated threads 13 is formed. The crossing points of the threads 13, in addition to the deflection aids 9 represent the knots of the framework.

The tube 35 is thus to a certain extent a "lost" manufacturing device, which provides the end product "cardan shaft" for the necessary tensile strength and bending stiffness.

Of course, several threads 13 can be wound in a composite around the tube 35. The threads 13 or the composite of threads 13 give after curing rods for a very stable framework, which ensures a secure, yet very easy connection of the flange 37 and the shaft end 39 with the tube 35.

In a fourth exemplary embodiment, a clamp 45, for example for fastening a pipe 47, is produced from the framework according to the invention made of fiber composite material. The finished clamp 45 with the tube 47 is shown in FIG. 29.

The clamp 45 in this case has a base frame 49 which is formed flat and, for example. can be attached to a wall with screws. On the base frame 49, a pipe cross-section adapted support for the tube 47 is arranged. The entire device (clamp 45 and base frame 49) consists of the framework according to the invention made of fiber composite material.

Figure 24 shows the preparation of the base frame 49. On a holding device 1 four trained as screws deflection aids 9 are arranged square or rectangular. The deflection aids 9 protrude in regions from the holding device 1 vertically out; they can also be encased with a sleeve, wherein the sleeve serves as a spacer for the holding device 1.

One or more resin-impregnated threads 13 are clamped longitudinally and diagonally about the projecting region of the deflecting aids 9, so that a framework of a dimensionally stable frame with dimensionally stable diagonal struts forms as the basic frame 49 after curing. The deflection aids 9 and the crossing points of the threads 13 form the knots and the hardened threads 13 form the bars of the framework.

FIG. 25 shows, independently of the production of the base frame 49, the first working steps for producing the actual clamp 45. To produce the clamp 45, the holding device 1 has two additional deflecting elements 9 'which are arranged on two rails 51 which can be displaced longitudinally on the holding device 1 , A displacement direction is indicated by arrows 53.

At the deflecting elements 9 and also the deflecting elements 9 'are longitudinally and diagonally one or more resin-impregnated filaments 13' tightly braced, these resin impregnated filaments 13 'for producing the clamp 45 above the base frame 48, ie away from the holding device 1, to the inventive Truss are braced. Figure 26 shows the device after completion of this step.

The following operation is shown in FIG. In this case, prior to curing of the threads 13 ', a model with the same cross-section of the pipe to be held later by the pipe 47 (or the pipe to be held 47 itself) is pressed vertically in the direction of the holding device 1 onto the truss. At the same time or slightly offset, the rails 51 in the longitudinal direction on the holding device 1 against each other, in the direction of the arrow 55, moved. The truss formed from the threads 13 'yields and settles around the forming tube 47. The still flexible (not hardened) truss attaches itself to the circumference of the tube 47. Now the truss can harden with curved bars.

In a further step, the base frame 49 must be connected to the actual clamp 45. The preparation for this is shown in FIG. 28 in an independent work step. For this purpose, when the rails 53 are pushed together, the deflection aids 9 are clamped by the further or several further resin-impregnated threads 13 "with the deflecting aids 9 '. The finished clamp 45 with base frame 49 and the holding device 1 is shown in FIG 29. Figure 30 shows the finished clamp 45 with base frame 49 in a plan view and two side views. FIG. 31 shows the finished clamp 45 with base frame 49 in a perspective view.

All threads 13, 13 ', 13' 'can be clamped in a composite of several threads on the holding device 1. The threads 13, 13 ', 13' 'or the composite of threads 13, 13', 13 '' give after curing rods for a very tensile and compressive-force stable framework, which is a very light clip 45 for secure fastening of pipes 47th creates.

The complete clamp 45 may, after completion, e.g. be screwed to a wall, in which by the deflection aids 9 and 9 'formed round openings in the framework fixing screws can be used. The clamp 45 thus produced weighs only a few grams. It can be used for all applications where a round or prismatic body has to be fixed. By the same procedure, for example, a holder could also be made on a bicycle for a drinking bottle.

Claims

A framework of a fiber composite material comprising a plurality of bars and a plurality of nodes, characterized in that the bars consist of one or more hardened threads (13, 15) arranged between the nodes, that the fibers of the threads (13, 15) through a Resin and / or a thermoplastic material are interconnected.
Truss according to claim 1, characterized in that in each case one or more nodes a sleeve (7) or a bolt-like element (5; 9; 9 ') is arranged, and in that the sleeve (7) and / or the bolt-like element (5 9, 9 ') is wrapped with one or more threads (13, 15).
Truss according to claim 1 or 2, characterized in that at least one node several threads (13, 15) wrap around.
Truss according to one of the preceding claims, characterized in that the truss has one or more functional surfaces (11), and that the at least one functional surface (11) by one or more threads (13, 15) is formed.
Truss according to claim 4, characterized in that the thread or threads (13, 15) extend parallel to a surface of the functional surface (11).
Truss according to one of the preceding claims, characterized in that the framework is a chainring (17) of a two-wheeler, that the attachment points of the chainring (17) are formed as nodes, and that the teeth (16) of the chainring (17) functional surfaces (11 ) are.
Method for producing a framework from fiber composites, comprising a plurality of rods and knots, wherein the rods consist of one or more threads (13, 15), that the fibers of the threads (13, 15) or a plurality of threads (13, 15) by a resin and / or a thermoplastic material are joined together, characterized by the following method steps: positioning at least one sleeve (7) and / or at least one bolt-like element (5, 9, 9 ') in a holding device (1), a sleeve (7) and / or the at least one bolt-like element (5; 9; 9 ') with one or more threads (13, 15); - connecting the fibers of the at least one thread (13, 15), and / or joining the plurality of threads (13, 15) - curing the threads (13, 15); and - removing the holding device (1).
A method according to claim 7, characterized in that the fibers of the at least one thread (13, 15) or the plurality of threads (13, 15) are interconnected by a resin or a thermoplastic plastic.
A method according to claim 7 or 8, characterized in that in the holding device (1) at least one shaped body (5) is positioned, which images a functional surface (11) or is a functional surface (11).
Method according to claim 7, 8 or 9, characterized in that the at least one thread (13, 15) connects the knots and / or the functional surfaces (11) such that at least one part, but preferably all, of the at least one thread (13, 15) are substantially coaxial with the force vectors acting on the truss during operation.
Method according to one of claims 7 to 10, characterized in that the framework after the winding or clamping of the threads (13, 15), preferably after curing of the resin or the solidification of the thermoplastic material, is pressed.
Method according to one of claims 7 to 11, characterized in that in the holding device (1) at least one in the longitudinal direction of the holding device (1) displaceable deflection aid (9 ') is arranged, wherein during manufacture, the initially strained threads (13, 15) be loosened by moving the at least one bolt-like element (9 ').
A method according to claim 12, characterized in that at the same time or offset in time to the movement of the displaceable deflection aid (9 ') one or more shaping bodies (47) are pressed against the threads (13, 15).