DE102010009671A1 - Apparatus for cut-machining workpiece containing thermoplastic matrix and reinforcement fiber, comprises cutting device, heating device spatially adjacent to cutting device, and spring-loaded sliding block to exercise pressure on workpiece - Google Patents

Abstract

The apparatus (1) for cut-machining a workpiece (10), which contains thermoplastic matrix and reinforcement fiber, comprises a cutting device (2), and a fixed heating device (3) spatially adjacent to the cutting device, and a spring-loaded sliding block to exercise a pressure on the workpiece. The machining apparatus and the workpiece are movable relative to each other along a predetermined cutting line at the workpiece. The positioning of the heating device is determined in dependent of an orientation of the cutting device with respect to a direction, in which the heat is emitted. The apparatus (1) for cut-machining a workpiece (10), which contains thermoplastic matrix and reinforcement fiber, comprises a cutting device (2), and a fixed heating device (3) spatially adjacent to the cutting device, and a spring-loaded sliding block to exercise a pressure on the workpiece. The machining apparatus and the workpiece are movable relative to each other along a predetermined cutting line at the workpiece. The positioning of the heating device is determined in dependent of an orientation of the cutting device with respect to a direction, in which the heat is emitted. The cutting device is a laser or a thermoforming cutting machine. The heating device is an infra-red radiation source, and comprises an optical element in an optical path of the emitted heat, where a focus of the optical element onto the workpiece coincides with the orientation of the cutting device. The cutting device and the fixed heating device are incorporated in a common housing (6). The laser beam of the cutting device is guided through a housing chamber, which has a housing opening, from which the laser beam exits. A supply line is provided in the housing chamber for supplying pressurized air. An independent claim is included for a method for cut-machining a workpiece.

Description

The The invention relates to a processing apparatus and a method for cutting a semifinished product or a component from a Composite fiber made of reinforcing fibers in one consists thermoplastic matrix.

at the increasing use of fiber composites that are beneficial combine good mechanical properties with a low weight, it comes in the processing of semi-finished products or components, in particular when cutting out breakthroughs and cutting contours to the problem that these are cropped after cutting or border area can delaminate, so that can move individual fibers or even dissolve out. Currently, the cutting of fiber-reinforced composite plastic semi-finished products, so-called prepregs, by punching or water jet cutting. When punching process is for each component a custom-made Tool, or a tool stamp needed, which means high investment costs, fully consolidated Fiber composite plastic semi-finished products, however, with small dimensions in large quantities cost-effectively assembled can be. However, in dry tissues, which are made from rovings, pultruded rods, hybrid yarns, and the like, are reinforcing fibers and thermoplastic fibers used for later formation of a matrix are not sufficiently fixed in the textile in order to subsequently stable in position to be punched or cut.

Of the Disadvantage of the water jet cutting process, the high pressure water jet used, is that some plastics have a large water absorption capacity may have, for example, polyamide, so this In case of water contact absorb water while keeping its properties change. Frequently, cuts can be made for Breakthroughs cut only after pre-punched hole or punched be, which is detrimental to the process or Manufacturing cycle times affects.

Although is from the prior art with the DE 42 39 556 A1 a device and a method for laser cutting, in which a workpiece is preheated before the action of the laser beam: For this purpose, preferably a gas burner is used, since it is the materials to be cut metal materials. However, such a device is not suitable for cutting a fiber composite plastic.

outgoing From this prior art, it is desirable to have a Processing device for cutting a semifinished product or to provide a component made of a fiber composite plastic, cut by means of a cutting edge with high precision can be while welding a weld the cutting edge is provided so that they do not delaminate can and the shifting, or the dissolving out single fibers is avoided.

These Task is by a processing device with the features of claim 1.

One Manufacturing method for cutting a semifinished product or a component made of a fiber composite plastic, which is used for manufacturing a variety of different cutting contours and breakthroughs can be used and by means of which any fiber composite plastic semi-finished, consolidated and non-consolidated, in particular textile reinforced thermoplastic plastic sheets, or films, made-up will be through the procedure with the characteristics of claim 7 provided.

further developments the device and the method are in the subclaims executed.

A inventive processing device is used the cutting of a workpiece, which consists of a thermoplastic matrix and reinforcing fibers exists without delamination at the cutting edge or a Displacement of loose fibers takes place. For this purpose points the inventive device advantageous except a cutting device, a fixedly spaced heat source, or heating device on. The heater is so positioned in the processing device that they heat radiates in a direction caused by the orientation of the cutting device is determined. Thus, simultaneously with the clipping process, heating takes place a straight cut or currently in trim Place the cutting line on the workpiece, causing the thermoplastic matrix melts around the reinforcing fibers, plasticized again and thereby binds the fibers in position, and thus the loss of fiber fixation caused by the cutting process, or the fiber composite, even before a potential delamination or prevents shifting of the fibers. The heater In this case, the cutting device can be provided in the machining tool. or may be downstream, under certain circumstances Also, several heaters may be provided, the cutting device can be upstream and downstream, and a beam path The radiated heat can be transmitted through an optical element the heater can be focused on the workpiece, and in particular at the point to which the cutting device is aligned.

The Workpiece may be a semi-finished or a component. fiber reinforced plastic workpieces with the invention Device can be edited from a thermoplastic matrix, for example polyamide, and consist of a coordinated semifinished textile product. these can Tissue, braids, nonwovens, knits and scrim include. For the production these semi-finished textile products can also be individually pultruded rods, impregnated rovings, hybrid yarns with plastic and reinforcing fibers, or combinations of these with each other and / or with dry rovings or textiles are used. The plastic matrix can also be formed solely by plastic fibers.

at The heater may be an infrared radiation source act.

There the machining device and the workpiece for execution a cutting edge along the intended cutting line relative can be moved to each other, can be used to smooth the workpiece and thus for improved precision of the cutting process a pressure on the workpiece by means of a corresponding suitable device, such as a spring-loaded shoe or a spring-loaded role. The order Such a device for exerting a pressure can one of the heater remote from the side of the cutting device in the processing device, but it can also be adjacent take place to the heater. In general, it is also conceivable more than a device for applying pressure to the processing device provided.

So takes place by a method according to the invention for cutting a workpiece from a fiber reinforced thermoplastic composite during the relative movement between the processing device from heating device and cutting device and the workpiece quasi simultaneously the cutting and heating of a predetermined on the workpiece Cutting line, or cutting edge, when the heating device of the cutting device is subordinate. Upon heating, the thermoplastic matrix becomes plastic melted along the cutting edge and after spacing the processing device, which is due to the relative movement results in a rapid solidification of the molten thermoplastic matrix of each cutting edge and thus for welding each cutting edge at remaining cutting gap, which incidentally by means of the on the cutting focus flowing gas jet, preferably Compressed air jet results. As a heater can in this context also a welding device are considered.

In order to is it not only possible to cut exactly semi-finished products, but also already shaped components to edit or to separate. Such a processing device is in particular also suitable to be arranged on a robot hand, by means of a programmed computer program the component to be processed can depart in all spatial directions, whereby also three-dimensional Structures can be cut with high precision.

These and further advantages are provided by the following description with reference to the accompanying figures.

Of the Reference to the figures in the description is for assistance the description and the easier understanding of the Object. Objects or parts of objects, which are essentially the same or similar be provided with the same reference numerals. The figures are merely a schematic representation of an embodiment of the Invention.

there shows

1 an enlarged view of a hybrid yarn cross section of reinforcing and thermoplastic fibers,

2 a schematic sectional view of an embodiment of the processing device according to the invention,

3 a view accordingly 2 a further embodiment of the processing device according to the invention,

4 a plan view of a board as a workpiece with an enlarged detail,

5 a schematic sectional view of another embodiment of the processing device according to the invention.

The processing device according to the invention serves to carry out a combined cutting and welding process, for example when cutting out breakthroughs and trimming contours for consolidated, unconsolidated fiber composite plastic semi-finished products, such as textile-reinforced thermoplastic plastic sheets and films. In the inventive execution of a continuous cutting process with simultaneous local heating of thermoplastic consolidated and non-consolidated fiber composite plastics prevents these delaminate with the continuous fibers after cutting in the cutting or edge area or move individual fibers or dissolve out.

Such Plastic sheets or films, or semi-finished or even Components with thermoplastic matrix and reinforcing fibers For example, a hybrid yarn fabric (not consolidated) or pre-consolidated organo-sheets. The reinforcing fibers include glass fibers, metal fibers, carbon fibers or aramid fibers and as a thermoplastic, a polypropylene, a Polycarbonate, a polyamide or an acrylonitrile-butadiene-styrene be used.

While when making breakthroughs or contours by means of Punching process requires a separate tool for each component and the waterjet cutting process for certain materials can not be used, the inventive Processing device in particular as a machining head of a Robot arm for a variety of different components and also be used for any combination of materials. The preparation of a pre-drilled hole for the production of breakthroughs is not necessary and it can reach short cycle times become. Furthermore, a loss of cut when using a laser as Cutting device can be minimized.

In 1 Fig. 3 shows a cross-section through such a hybrid roving R which contains as reinforcement fibers VF glass fibers and thermoplastic fibers TF, for example polyamide, which are encased in a thermoplastic TM which forms hybrid yarn (eg commingling). If such a hybrid yarn is cut according to the invention and simultaneously heated at the cutting edge, the thermoplastic fibers TF and the thermoplastic envelope TM are melted at the cutting edge by the heat input and welded to the reinforcing fibers VF, so that the fibers can not move or detach.

A Material supply to the cutting process can be continuous, such as at Textile reinforced thermoplastic sheets by Take off from a roll, but it can also be discontinuous, for example, by inserting plates, such as preconsolidated Organo sheets in a holder, made to carry provided the cutting and welding process according to the invention is.

to Execution of the cutting edges can either the processing device or the workpiece is moved by means of a suitable holder if necessary, both can also be moved, so that in any case a relative movement between the processing device and workpiece takes place.

A processing device according to the invention 1 , is in 2 . 3 . 5 shown, in 2 and 3 a laser as a cutting device 2 is provided. As a heater is in each case an infrared radiation source 3 provided in 2 Heat line in the direction of the workpiece 10 radiates, so that when performing the relative movement according to block arrow a by the laser focus 12 manufactured cutting edge is heated immediately after making the cut.

In 3 and 5 shows the heater as optical element a converging lens 3 ' , By means of which the heat radiation punctiform on the workpiece 10 is focused, in accordance with an orientation of the respective cutting device, in 3 a laser beam and in 5 a thermoforming mandrel 2 , Regardless of which machining head is used, local heating of the thermoplastic matrix occurs along the cutting edge in the workpiece 10 instead, whereby the trimmed reinforcing fibers are plasticized and welded in the edge region after cooling.

A method according to the invention can be carried out using a hybrid laser head 1 , as in 2 and 3 shown next to the laser 2 also the heater 3 fixedly spaced apart on a blanking table of an associated cutting / welding apparatus or thermoforming machine, which is provided with a holder for the workpiece 10 - Not shown -Equipped, which is supplied separately. Also conceivable is a variant in which the cutting process using a hybrid laser head 1 directly after a manufacturing process of the semifinished product 10 takes place from fiber composite plastic, for example, a hybrid yarn, in which the inventive processing device 1 can be integrated in a weaving machine. As heat sources in addition to an infrared radiation source and hot air blower, lambda emitters or combinations thereof, in question. In connection with the cutting process, it may be advantageous if the workpiece 10 is processed by means of breakthrough forms, which then proves to be gentle on the fiber in the cutting process.

In 2 and 3 is for exerting a pressure on the workpiece 10 a by means of a spring 8th with a restoring force acted sliding shoe 4 represented here in each case according to the direction of movement according to arrow a of the combined cutting and welding device is upstream. Instead of the sliding shoe 4 can also be used a roller, by means of which due to the omission of the sliding friction between the device and the workpiece 10 this is protected against abrasion or delamination.

As a general rule conceivable, but not shown, is the arrangement of a Sliding shoe or roller after the cutting and heating device or, when using two or more shoes, a pre- and post-storage. This allows ripples of the surface of the workpiece, respectively of the foil, are eliminated, so the focus the laser defined within the wall thickness of the workpiece is present. The focal point can either span both opposing cut edges or only on the cut edge good side, so the cutting edge of the Section of the workpiece that is installed and, if necessary, previously should be processed, lie.

The heater 3 is in 2 and 3 shown downstream, with in 2 the heat radiation line on the workpiece 10 according to the direction of movement arrow a after the cutting device 2 is arranged, and in 3 by means of collecting lens 3 punctiform with the focus 12 the laser 2 coincides. However, the heater may also be upstream, or it may be provided on the processing device several heat sources, which are upstream and downstream.

alternative but can also be a device for active cooling, for example represented by a water-cooled edition, after successful Cutting machining be provided to the solidification of the cutting edge to take place quickly and thus the shifting of the fibers, or to prevent a bleeding of the edge.

In order to allow in particular during the start-up phase in the breakthrough displacement of the resulting melt, is in the embodiments of 2 and 3 shown that the cutting device 2 and the fixedly spaced to this adjacent heater 3 in a common housing 6 are received, wherein the laser beam of the cutting device 2 through a housing chamber 6 ' is guided, in which a supply line 5 for supplying a gas such as compressed air flows. The supply can be switched on if necessary and the gas pushes through the housing opening 6 '' from which the laser beam 12 exits, so that the gas, possibly only during the start phase of the execution of a breakthrough, the melt removed or at least displaced and at the same time also generates a cutting gap along the cut. The compressed air jet also cools the cutting point.

Also stuck to the cutting device 2 arranged heating device 3 is in a housing chamber 6 ' adjacent in the common housing 6 picked up, leaving the housing chamber 6 ' also for the desired positioning of the heater 3 with respect to the orientation of the laser beam 2 provides.

The sliding shoe 4 or the role is on this case 6 coupled.

Simplified as laser optics is a condenser lens 7 represented by means of the focal point 12 of the laser beam 2 on the workpiece 10 is focused. A detailed design of a laser cutting head is known from the prior art.

In 4 is a board to be machined workpiece 10 a Z-strut of a Frontendträgers shown with a plurality of cut edges to be produced 11 ' , This can be circumferential trim contours 11 ' as well as within the workpiece 10 present breakthroughs 11 ' be that are very accurate to manufacture. With reference to detail B, the cutting line provided for the cutting device is enlarged 11 for the production of the cutting edge 11 ' shown. Starting point of the cutting process is the saddle point 12 within the breakthrough to be made. The focal point 12 the laser is then guided over the workpiece according to the intended cutting line indicated by the arrows, while the heating of the cut edge thus prepared 11 ' for a welding of the same and thus ensures an exact execution.

In 5 is an alternative processing device 1 illustrated in which the cutting device 2 not as previously realized by a laser, but by a heated mandrel 2 a thermoforming apparatus. The heated spike 2 that by means of a rotary motor 9 is rotatable and via a compression spring arrangement 8th Can perform vibrations, especially for workpieces 10 be used with greater depth extent, in which a laser is less suitable. Advantageously, in the production of holes or breakthroughs they may already be preformed, which has a fiber-friendly effect. Again, the heater is 3 at a fixed distance and orientation to the cutting device 2 formed by the thermoforming mandrel ge, in the housing 6 arranged, in which case the heater is shown as a focusing infrared emitter whose focal point according to the orientation 12 of the thermoforming mandrel 2 is positioned. This is the place to edit 12 before and after lowering the thermoforming mandrel 2 heated. The heat source can also, as in 2 shown to be designed as a linear heat source. Alternatively, the heat source by a variotherme inductive tool temperature control in the area of the support of the workpiece 10 be replaced. The overlay is heated to about 220 ° C to 270 ° C using PA as a plastic matrix. With the heated mandrel 2 it is also possible in a simple manner to mold holes in the warm tissue or to expand existing holes.

By the combination of a cutting and welding process becomes a detachment of the reinforcing fibers in the cutting area avoided. The panels to be cut can be closer together (better "nesting"), allowing better material utilization is possible. Also, the defined fiber arrangement Improved component properties in the marginal area. A force transfer from overmolded material in the edge area the fiber composite plastic structure is more direct and thus better.

A Partial plasticization of the matrix is when using semi-finished products / components with thermoplastic matrix easily possible. fibers in the edge area, which may not be wetted by the melted in the process according to the invention Matrix wets, creating a better force transfer of Matrix material, or the overmolded material in the edge region he follows.

The Handling such a trimmed prefixed textile, for example an organic sheet or a limp hybrid yarn fabric or -textiles, is facilitated because the fibers in the cut edge area and also in the area due to the welding - punctually or consistently - are fixed and not can move or detach more. One possibly heated, limp and loosely arranged Fibers prefabricated semi-finished can then easily in a corresponding Injection mold are introduced for completion.

at a semi-finished with loose reinforcing fibers can these before the cutting process by means of flat or punctiform Heating and subsequent cooling of the plastic matrix be fixed. The matrix can consist of plastic fibers, the when heated melt and the reinforcing fibers wrap. By the solidification of the fiber melt after the cooling, the reinforcing fibers are unverbarbar positioned and strengthened the tissue structure without causing unwanted holes caused by displacement of the reinforcing fibers can.

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• - DE 4239556 A1 [0004]

Claims (9)

Processing device ( 1 ) for cutting a workpiece ( 10 ) comprising a thermoplastic matrix and reinforcing fibers, wherein the processing device ( 1 ) and the workpiece ( 10 ) along one of the workpiece ( 10 ) predetermined cutting line ( 11 ) are movable relative to each other, characterized in that the processing device ( 1 ) a cutting device ( 2 ) and a fixedly spaced adjacent to this heating device ( 3 ), wherein a positioning of the heating device ( 3 ) with respect to the direction in which heat is radiated, depending on an orientation of the cutting device ( 2 ) is determined. Processing device ( 1 ) according to claim 1, characterized in that - the cutting device ( 2 ) is a laser or a thermoforming cutting device and - the heating device ( 3 ) is an infrared radiation source. Processing device ( 1 ) according to claim 1 or 2, characterized in that the heating device ( 3 ) in an optical path of the radiated heat, an optical element ( 3 ' ) whose focus on the workpiece ( 10 ) with the orientation of the cutting device ( 2 ) matches. Processing device ( 1 ) according to at least one of claims 1 to 3, characterized in that the processing device ( 1 ) a device ( 4 ), in particular a sprung sliding shoe ( 4 ), for exerting a pressure on the workpiece ( 10 ). Processing device ( 1 ) according to at least one of claims 1 to 4, characterized in that at least the cutting device ( 2 ) and the fixedly spaced to this adjacent heater ( 3 ) in a common housing ( 6 ), wherein at least the laser beam of the cutting device ( 2 ) through a housing chamber ( 6 ' ), which has a housing opening ( 6 '' ), from which the laser beam ( 12 ), and wherein a supply line ( 5 ) for supplying a gas, in particular compressed air, into the housing chamber ( 6 ' ). Method for cutting a workpiece ( 10 ) comprising a thermoplastic resin matrix and reinforcing fibers using a processing device ( 1 ) according to at least one of claims 1 to 5, comprising the steps - during the execution of a relative movement between the workpiece ( 10 ) and the processing device ( 1 ) simultaneously heating a cut edge ( 11 ' ) on the workpiece ( 10 ) and cutting along the heated cutting line ( 11 ) while doing the cutting edge ( 11 ' ) Melting the thermoplastic matrix along the same, and - welding the cut edge ( 11 ' by solidifying the molten thermoplastic matrix. Method according to claim 6, comprising the step of smoothing the workpiece ( 10 ) by applying pressure to the workpiece ( 10 ) during the relative movement. Method according to one of claims 6 or 7, characterized in that lying loose before the cutting process Reinforcing fibers by means of flat or punctiform Heating and subsequent cooling of the plastic matrix be fixed. Method according to one of claims 6 to 8, characterized in that the plastic matrix by plastic fibers provided.