DE102012005973A1 - Method of bending thermoplastic fiber composite pipe e.g. fiber reinforced plastic (FRP) pipe, involves locally heating to-be-bent pipe sections of pipe by heaters only up to deformability and bending at locally heated pipe section - Google Patents

Abstract

The to-be-bent pipe sections (20') of FRP pipe (20) are locally heated by the heaters (9) only up to deformability. The heater is removed from the to-be-bent pipe sections. The pipe is bent at the locally heated pipe sections by a bending unit (3) while supporting the inner side of pipe section with a mandrel (4). The curved pipe section is cooled and mechanically supported for the curing of the pipe section. Independent claims are included for the following: (1) thermoplastic fiber composite pipe bending machine; and (2) thermoplastic fiber composite pipe manufacturing device.

Description

The invention relates to a bending plant for thermoplastic fiber composite pipes (FRP pipes), as well as a production plant for bent thermoplastic fiber composite pipes, which includes the bending machine, and also a corresponding forming process that can be performed with the bending machine.

Bending equipment, also automated bending equipment for the deformation of metal pipes are known from the prior art. With the bending machines, the free-form or the Rotationszugbiegen can be performed. Such systems usually include a bending unit and a clamping unit, one of which is movable in order to bend the pipe at the desired location.

A bending device for Freeform bending of longitudinal profiles is in the DE 10 2005 013 700 B3 described. The device comprises a feed unit which detects the longitudinal profile, and an axial sleeve which is arranged downstream of the feed unit in the feed direction and which detects the longitudinal profile in a positive and / or non-positive manner. This is arranged downstream of a bending sleeve with a matched to the outer contour of the longitudinal profile passage opening for the longitudinal profile in the feed direction. The bending sleeve is linearly adjustable by means of actuators in a plane orthogonal to the axis of its passage opening and pivotable about an axis perpendicular to both the axis of the passage opening and the direction of the linear adjustment axis. Furthermore, the axial sleeve is equipped with a drive, with their distance from the bending sleeve can be adjusted. The forming of the tube is done solely by changing the position of the bending die. With this device, a pipe can be subjected to bending operations immediately after its manufacture in an endless process.

For forming of cut pipe sections is from the DE 20 301 138 U1 a bending machine for clamping and bending of pipes with a fixed clamping unit for fixing the pipes and only one hand movable bending unit known. The pipes to be bent are fixed against rotation with one end in a collet chuck of the fixed clamping unit. The bending unit, which is freely movable along the tube axis with respect to the clamping unit and the tube fixed therein, has a bending head with a bending tool which makes the necessary movements to produce the desired bend of the tube, moving freely around the fixed tube at the bending unit can.

That in the DE 101 06 741 C2 The disclosed method makes it possible to bend a pipe at least twice, using a bending tool with a fixed bending roller and a pivoting deflection roller, between which the pipe is arranged. The bending tool is moved along the tube to a predetermined bending point and there takes a bending position, in which the tube is clamped. The tube is bent at the bending point in a predetermined manner, and a portion of the tube between the bending point and a clamping point, to which the tube is fixed, is subjected to a rotational movement about the longitudinal axis of the section by means of the bending tool, so that a vibratory movement of a remaining Tube section is damped before the bending tool goes back to its displacement position and moves to a next bending point.

The bending of metal tubes or longitudinal profiles, however, can not be readily transferred to fiber composite pipes due to the material inherent properties, so that the continuous deformation of fiber composite pipes with thermoplastic matrix by means of CNC technology has not been done.

Based on this prior art, it is an object of the present invention to provide a bending system and a corresponding bending method for forming thermoplastic fiber composite pipes. Furthermore, the object of creating an entire manufacturing plant, which makes it possible to produce curved, thermoplastic fiber composite pipes in a single manufacturing process.

These objects are achieved by the method with the features of claim 1 and by a bending machine with the features of claim 5 and by the manufacturing plant with the features of claim 10. Further developments of the method and the application are set forth in the corresponding subclaims.

• – lokal begrenzt Erwärmen des thermoplastischen Faserverbundrohrs mit zumindest einer Heizvorrichtung an zumindest einem zu biegenden Rohrabschnitt bis zur Verformbarkeit,
• – Entfernen der Heizvorrichtung von dem zu biegenden Rohrabschnitt und Biegen des Rohrs an dem lokal erwärmten Rohrabschnitt mittels einer Biegeeinheit, dabei innenseitig Stützen des Rohrabschnitts mit einem Biegedorn,
• – Kühlen und mechanisch Stützen des gebogenen Rohrabschnitts bis zum Aushärten des Rohrabschnitts.

The process according to the invention, which also makes it possible to bend thermoplastic fiber composite pipes, comprises the steps:

• Locally limited heating of the thermoplastic fiber composite pipe with at least one heating device on at least one pipe section to be bent to the ductility,
• Removing the heating device from the tube section to be bent and bending the tube at the locally heated tube section by means of a bending unit, while supporting the tube section on the inside with a bending mandrel,
• - Cooling and mechanically supporting the bent pipe section until curing of the pipe section.

Due to the exclusively local, defined heating, the material-friendly only to the deformability of the heated points is performed, and by the inside supports the tube by means of a mandrel system so advantageously collapsing, buckling or unwanted deformation of the cross section of the tube is avoided at the bending point.

Advantageously, the bending process may also provide for deforming a cross-sectional shape of the tube at least in the heated portion during bending or after bending.

The mechanical supports can be suitably automated by means of a robot-guided gripper device; Furthermore, in order to avoid material damage during bending of the thermoplastic fiber composite pipe, a compensation movement of the mechanically supported bent pipe section can optionally be carried out on a second section.

Bending may be performed as "free-form bending," "rotary-pull bending," or "compression-bending" according to methods known from metal forming.

It can be carried out either on a continuously produced thermoplastic fiber composite pipe (also referred to herein for short as a pipe), which is moved at a certain feed speed, as well as on a cut-to-length pipe.

In the thermoplastic fiber composite pipe, heating, bending, cooling, and supporting are performed at the portion moving at the feed speed; This is followed by a cutting step in order to obtain a tube of the desired length from the thermoplastic fiber composite pipe or even tubular pipe.

• – einen Biegedorn zur innenseitigen Stützung des Abschnitts,
• – zumindest eine Kühlvorrichtung zur Kühlung des gebogenen Abschnitts,
• – und zumindest eine der Biegeeinheit nachgeordnete Stützvorrichtung zur Stützung des gebogenen Abschnitts.

The method can be advantageously carried out with a bending system for such thermoplastic fiber composite pipes. This comprises a bending unit and a clamping unit, which are movable relative to each other, and at least one movable to a portion to be bent portion of the thermoplastic fiber composite tube heater; further

• A bending mandrel for inside support of the section,
• At least one cooling device for cooling the bent section,
• - And at least one of the bending unit downstream support device for supporting the bent portion.

The bending equipment may optionally comprise a deformation device with which the cross-sectional shape of the pipe can be changed. This deformation device can be arranged downstream of the bending unit or integrated into the bending unit.

The bending mandrel is advantageously material-friendly, at least on its surface of an elastomeric material, this material can be further supported by a provided at its tip nose, which consists of a plastic, a ceramic or a metal material.

• – ein massiver Vollelastomer-Biegedorn oder ein Biegedorn aus einem Vollelastomer-Hohlrohr sein, oder
• – einen Gliederdorn oder einen Schuppendorn mit einer Elastomerhülle umfassen, oder
• – einen Seilkern mit einer Elastomerhülle umfassen, oder
• – einen Seilkern oder Gliederdorn oder einen Schuppendorn mit einer Elastomerhülle umfassen, die zumindest eine aufweitbare Kammer aufweist, oder
• – eine in einen Seilkern eingedrehte Gliederkette und eine Elastomerhülle umfassen, oder
• – eine in einem Elastomerschlauch eingebettete Schraubenfeder, die bevorzugt aus Metall ist, umfassen.

The bending mandrel can be about

• Be a solid full elastomer bending mandrel or a mandrel made of a full elastomer hollow tube, or
• - comprise a mandrel or a Schuppendorn with an elastomer shell, or
• Comprise a cable core with an elastomeric sheath, or
• Comprise a cable core or a mandrel or a Schuppendorn with an elastomeric sheath having at least one expandable chamber, or
• Comprise a link chain screwed into a cable core and an elastomer shell, or
• - An embedded in an elastomeric hose coil spring, which is preferably made of metal, include.

The cooling device of the bending installation according to the invention can at least be an apparatus for active external cooling, preferably a cooling ring or a vortex nozzle, which is arranged downstream of the bending unit or the deformation unit, or a device for active internal cooling, preferably a vortex tube arranged in the FRP pipe, of which a supply line extends through the bending mandrel, which opens into the section. Additionally or alternatively, a device for passive or partially active cooling, which is preferably formed by a cooling device integrated in a gripper device, the cooling lines, are formed. In this case, the gripper device is preferably guided by a robot and particularly preferably provides the support unit downstream of the bending unit.

The heating device of the bending machine according to the invention may comprise a plurality of IR radiators, which are arranged in a housing around the pipe. Furthermore, the heating device can be movable in a longitudinal direction along the tube and / or in a direction perpendicular thereto. If the heating device is movable perpendicular to the tube, it comprises a housing which can be opened.

A production plant according to the invention for bent, thermoplastic fiber composite pipes comprises the bending plant likewise according to the invention, which is designed to bend a continuous pipe or raw strand strand, as well as a manufacturing plant, which is arranged downstream of the bending machine in the process direction. The manufacturing plant is preferably a pultrusion plant or a tape-laying device, or another continuous production unit for the production of endless FRP semi-finished products, wherein the clamping unit is formed by the manufacturing plant, and wherein the bending machine in relation to the manufacturing plant along the feed rate of the manufacturing process Tube is movable.

These and other advantages are set forth by the following description with reference to the accompanying figures. The reference to the figures in the description is to aid in the description and understanding of the subject matter. Articles or parts of objects which are substantially the same or similar may be given the same reference numerals. The figures are merely a schematic representation of an embodiment of the invention.

Showing:

1 FIG. 2 a schematic side sectional view of a bending installation according to the invention, which is arranged downstream of a braided-pultrusion installation,

2 FIG. 2 a schematic side sectional view of a bending installation according to the invention with integrated downstream annular nozzle for external cooling, FIG.

3 a schematic side sectional view of a bending system according to the invention with downstream vortex tubes for external cooling,

4 a tempered gripper for holding a bent pipe section,

5a) a schematic plan view of the bending tool downstream or integrated therein Nachverformungsvorrichtung for
Pipe cross section variants and
b) a sectional view along AA of a),

6 FIG. 2 a schematic side sectional view of a bending installation according to the invention with a post-deformation device integrated in the bending tool, FIG.

7 Side sectional views of various bending mandrel variants: full elastomer mandrel with attached nose (a), thick-walled elastomer tube as mandrel with attached nose (b), mandrel with elastomer shell (c), rope core with elastomer shell as mandrel (d), a rope core twisted around a link chain with elastomer shell (e) , Cable core with double-walled elastomer sheath (f), elastomer hose with embedded helical spring as mandrel (g), and a perspective sectional view of a shearing horn with elastomer sheath (h),

8th a schematic representation of the automated handling of cut-to-length pipes before and after bending using robot technology,

9 stepwise a) to k) the bending of a cut-to-length pipe at two bending points with a rotary tension bending machine with a fixed bending unit and a movable clamping and advancing unit,

10 stepwise a) to i) bending a cut-to-length pipe at two bending points with a rotary tension bending machine with movable bending unit and fixed clamping unit,

11 a cross-sectional view through a heater according to the invention with individually controllable IR units,

12 a schematic side sectional view of a bending system according to the invention for cut tubes with four heaters and movable bending unit and fixed clamping unit,

13 three cross-sectional views of contact surface and thus friction-reducing peripheral designs of the mandrel guide lance,

14 a cross-sectional view of the guide lance with circumferentially distributed interchangeable sliding elements.

The invention relates to a bending plant for thermoplastic fiber composite pipes (FRP pipes), as well as a production plant for bent thermoplastic fiber composite pipes, which includes the bending machine, and also a corresponding forming process that can be performed with the bending machine. In order to ensure a continuous bending process in FRP pipes, in which a desired pipe run and possibly also a desired pipe shape is achieved, according to the invention the FRP pipe or the endless pipe string is heated locally only at the one or more points to be bent and the pipe becomes the material gently protected only to deformability bent points, where it is supported on the inside by means of a mandrel system to avoid collapse, kinking or unwanted deformation of the cross section of the pipe at the bending point. The tube is selectively cooled at the bent portion and at the same time supported mechanically, preferably by means of a gripper device guided by a robot, so that the bent tube section in the desired shape hardens upon cooling. Optionally, a deformation unit may be connected or integrated into the bending device by means of which the cross-sectional shape of the tube is changed.

The bending systems according to the invention for the forming of fiber composite plastic pipes solve the problems of feeding the pipes to the bending machine, heating the pipes in the process, cooling the pipes in the process and handling the pipes during and after the bending process. And it is the post-deformation, or online deformation of the pipe cross sections and the inner support of the pipe systems made possible by novel mandrel systems.

A first CNC-suitable bending system according to the invention is based on the principle of free-form bending, for example in the patent specification DE 10 2005 013 750 B3 described. The deformation of the tube is effected by the change in position of the bending die. This method, by virtue of its mode of operation, represents an ideal implementation for an endless process and can therefore be subordinated to a pultrusion plant with which a continuous FRP pipe is produced.

An installation arrangement for the process flow is in 1 displayed. The production of the FRP pipe 20 takes place in a Flechtpultrusionsanlage 50 with three braiding wheels 51 , with which three fiber layers are braided on a braiding mandrel. The fibrous material comprises the thermoplastic matrix plastic. In addition to reinforcing fibers, thermoplastic fibers may also be interlaced; alternatively, a hybrid yarn comprising reinforcing fibers in a matrix size may be used. In addition to single fibers, it is of course also possible to use fiber bundles (rovings) or fiber tapes (tapes).

The thermoplastic matrix may be ready for entry into the pultrusion or consolidation tool 53 for example, by an IR emitter 52 heated to pass through the feeder matrix 55 to support, for example, around a fiber jam to avoid. In the pultrusion or consolidation tool 53 The thermoplastic matrix is heated to the melting point, so that the reinforcing fiber braid is completely penetrated by the matrix before it is cured by controlled cooling. The pultrusion process is driven by the double belt take-off 54 , the pultrusion or consolidation tool 53 is subordinate and then finished FVK pipe 20 withdraws.

The FRP pipe 50 In addition to the described braiding pultrusion process, pipe production via tapewinding or other endless production technologies for thermoplastic composite fiber composite pipes is also possible directly after the production process, in a bending installation according to the invention 15 bent.

To do this, go through the tube 20 after leaving the production line 50 a new heating area 9 , This heating area 9 consists of several separate IR radiator systems 29 which are circular around the pipe 20 are arranged (see 11 ).

These individual spotlights 29 can be regulated individually in terms of performance and thus make it possible to obtain a feed movement V _a (see FIG 2 . 3 . 6 ) targeted to heat from the manufacturing process moving point on the regulation of the individual IR areas. So that's what the tube has to do 20 not completely heated, but it is possible only targeted areas 20 ' of the pipe 20 to heat up and that too when the pipe is 20 moved at a certain feed rate V _a . This will be explained in more detail below.

Then the tube goes through 20 a partly tempered freeform unit 2 . 3 , see. also 2 . 3 and 6 , After leaving this freeform unit 2 . 3 has the pipe 20 the desired bend and, if, as in 6 shown and will be explained later, a corresponding cross-section forming device 2 is provided, also get the desired Außenkontor. In order to prevent the return of the possibly still warm pipe, this is then additionally robotic units 21 supported, as shown schematically in, for example 8th . 9 and 10 are sketched. Has a pipe section that corresponds to a complete component, the forming line 15 This happens via a separation unit from the rear endless part of the pipe 20 separated and can be fed to a subsequent process.

Alternative to that related to 1 . 2 . 3 and 6 described continuous bending machine, a bending system for already cut to length pipes can be used, which is based on the Rotationszugbiegen. For this purpose, a bending process can be realized which describes a forming process in the DE 10 106 741 C2 or in the DE 20301138 U1 equivalent. Since here the bending tool is rotationally moved around the tube, the fundamental condition is met here, too, that the tube should not be moved rotationally during the bending process.

Another inventively applicable bending process that can be used for already cut to length pipes, that is Compression bending. Of course, the free-form bending with truncated tubes described above with respect to bending in the endless process can also be performed. The cut pipe is "pushed" by a feed unit through the fixed bending unit.

The machine construction of the bending plant necessary for the transformation of fiber composite pipes for the processing of already cut to length pipes 20 is doing in 9 and 10 described with the steps performed for bending. There are two different modes of movement of the system.

In the 9a) to k) has a fixed bending unit 2 . 3 that the pipe 20 penetrates, and one on a track 25 movable clamping and feed unit 24 based on the operation of a standard CNC rotary tension bending machine.

Next to the fixed bending unit 2 . 3 the plant has a fixed mandrel system, which is a holder 4 ' comprising the guide lance holding the mandrel 7 holding. The mandrel system can hydraulically, pneumatically or electrically driven via an internal control realize small travels to possibly extract the mandrel over the range of members from the bending area. The mandrel is in the clamped FRP pipe 20 arranged and therefore not visible; it extends along the bending point at the bending unit 2 . 3 , The movable clamping and feeding unit in which the FRP pipe 20 is clamped between the fixed bending unit 2 . 3 and the mandrel holder 4 ' arranged. Ie. here is the pipe 20 from the clamping and feed unit 24 emotional. This movement leads on the one hand to the respective pipe section to be bent to the bending unit 2 . 3 On the other hand, for example, it executes the compensatory movement in the rotational tensile bending process.

After clamping the pipe to be bent in the bending plant ( 9a ) are the movable, individually controllable heaters 9.1 . 9.2 . 9.3 . 9.4 at the pipe sections to be bent 20 placed. The heaters 9.1 . 9.2 warm up a first bend 20 ' and the heaters 9.3 . 9.4 a second ( 9b ).

If, as in this example, several areas are heated at the same time, in the unheated area between the heated sections 20 ' additional support. This can, as in 9c) shown by means of a robot 21 respectively. Of course, other clamping systems, even in the machine integrated gripping systems are conceivable. This additional support serves to prevent the distortion or deformation of the heated areas due to a feed or bending movement. If more than two heating points are arranged one behind the other, preferably additional support should be provided between each of these areas.

Is at least the first bending point 20 ' heated to ductility, as in 9d) to see their heaters removed, leaving only the heaters 9.3 and 9.4 the second bending point on the pipe 20 remain. Like arrow v ₁ in 9e) then becomes the pipe 20 from the clamping and feeding device 24 so moved that the first bend 20 ' in the bending unit 2 . 3 is arranged.

During the advancing movement of the pipe 20 become the heaters 9.3 and 9.4 as well as the supporting robot 21 move synchronously with the tube movement v ₁ , as indicated by the arrows v ₂ and v ₃ , to avoid shifting the heated laminate levels.

In an alternative plant and process management, the elimination of the additional support unit 21 would enable the heating of the next bending points is only begun when the bending point currently in bending is completed bent. This can be prevented that due to the passage of the tube during Rotationszugbiegen a change in the laminate alignments takes place in any heating areas behind the actual bending point. The control of the laminate behavior in the bending area by pressure and tension is then here, as in a normal Rotationszugbiegeprozess of metal pipes on a CNC machine, from the clamping and feed unit 24 accepted.

Because when bending the tube 20 During Rotationszugbiegen a new feed force v _b by pulling the tube 20 arises, this must also from the three components supporting robot 21 , Heater 9.3 . 9.4 and clamping unit 24 to be compensated ( 9f ). It can with the gripper 21 behind the first bend 20 an additional effect can be achieved: this can by movement deviating from the pipe feed v _b both a compressive force, as well as a tensile force on that of the bending unit 2 . 3 affect the pipe section to be bent. Thus, for example, the laminate behavior in the bending area can be controlled. Thus, in the bending process, material can be kept out of the bending area or fed in.

After bending the tube 20 at the first bending point, the bent pipe end is also by means of a robot 21 that with a like in 4 shown tempered gripper 14 can be equipped, supported ( 9g ). For bending the second bending point, the first supporting robot 21 and the remaining heating devices 9.3 . 9.4 removed, and the pipe 20 from the clamping unit 24 advanced until the second bend 20 ' in the bending unit 2 . 3 is placed ( 9h) and i). Synchronously, the robot supporting the bent pipe end becomes 21 with procedure. As 9j) can be removed, occurs during the second bending process, a feed movement v _{b of} the tube 20 on, synchronously the clamping and support unit 24 is moved. The robot supporting the bent pipe end 21 In doing so, it performs a movement b compensating both the feed and the rotational movement of the tube. Subsequently, another robot supports 21 the second bend until the pipe 20 cooled to deformation ( 9k ).

In the second movement mode, the actual bending unit is moved from bending point to bending point and the clamping unit is fixed. In 10a) to i) shows a corresponding plant and the process steps carried out with it. Here are the bending unit 2 . 3 that go along the pipe 20 is moved, and the mandrel holder 4 ' on rails 25 arranged. The clamping and feed unit positioned in between 24 is certain.

For both in connection with 9 and 10 described systems, a mandrel integration is provided. In principle, this mandrel integration is based on the mandrel systems already available in series, which are also used in rotary-pull bending machines. In the process, the actual mandrel, built up with limbs or otherwise, is passed over a lance 7 positioned at the location needed for the bend. While in a fixed bending unit, the mandrel system is also fixed, it is for a bending machine, as in 10 described, with a movable bending unit 2 . 3 required, also the mandrel on the guide lance 7 and the holder 4 ' movable, so that the mandrel synchronized with the bending unit 2 . 3 From bending point to bending point can be moved, or as shown in steps f) and g), the mandrel by the movement V _{D of} the holder 4 ' at the second bend 20 ' is placed before the bending unit 2 . 3 according to the arrow V _B to the bending point 20 ' is moved. This is the mandrel or the guide lance 7 on a movable bracket 7 clamped.

Again, the pipe is 20 partially at the sections to be bent by means of the movable and individually controllable heating devices 9.1 . 9.2 . 9.3 . 9.4 heated to allow reshaping.

In 10a) heats a heating unit of four heaters 9.1 . 9.2 . 9.3 . 9.4 the intended bending points of the pipe 20 , After the heaters 9.1 . 9.2 the first bend 20 ' are removed ( 10b ), moves the bending unit 2 . 3 to the first bend 20 ' where the thorn over the guide lance 7 and the movable bracket 4 ' already placed correctly ( 10c ), and performs the bending operation ( 10d ). The bent pipe end is also here by a robot 21 supported, which also with an optionally tempered or temperature-controlled gripping device 14 can be equipped ( 10e ). Now also the heaters 9.3 . 9.4 at the second bend 20 ' away ( 10f ) and the mandrel by moving v _{B of} the holder 4 ' in the second bend 20 ' positioned. Then the second bending point 20 ' through the beige unit 2 . 3 approached (arrow v _B in 10g) , so that the forming of the tube 20 at the second bending point ( 10h ), wherein the curved end supporting robot 21 performs a compensation movement. The second bending point is also controlled by a robot 21 supported ( 10i ).

In all cases, d. H. In all bending systems, the heating of the pipes should be done partially at the locations intended for the bending and preferably not over the entire pipe.

For this, the tubes can be taken directly from the pultrusion process 50 , as in 1 shown in still warm, but deformation-resistant state of the bending machine 15 be supplied. The main heating section then forms separately controllable IR emitters in the area behind the bending zone 9 which around the pipe 20 are arranged around, as in 11 you can see. The separate controllability makes it possible to selectively control with a moving pipe, the heat input zone with the pipe feed. The feed and / or the heating power are adjusted so that the time in the IR path is sufficient to achieve complete heating of the thermoplastic matrix of the tube.

The heater 9 that of each of the heaters 9.1 . 9.2 . 9.3 . 9.4 corresponds to include a plurality of IR emitters 29 in the in 11 example shown are distributed in a housing with octagonal cross section and thus approximately circular to the FRP pipe 20 are arranged. The FVK pipe 20 enclosing housing can, as in 11 represented by two by a hinge 17 foldable connected half-shells and thus be opened (arrows o) to the heater 9 individually on the pipe 20 to arrange and remove. This can be the open heater 9 In order to be removed from the feed area of the pipe, be moved in the direction of the double arrow s.

Thus, virtually endless or non-continuous tubes made of fiber composites with thermoplastic matrices after complete consolidation, produced in a plant 50 corresponding 1 , a tape wrapper or similar equipment directly or cut to a bending process supplied. The tubes can be fed directly after the production, but also after intermediate storage the bending process. In all cases, the individually movable and controllable heaters are used, with which the heating of the tubes via the approximately circular arranged around the tube IR emitter takes place. By consisting of several individual separately controllable heating heaters heating unit targeted only the forming areas can be heated.

The variant with the like in 11 shown hinged heater is mainly for use in a bending system, as in 10 and also 12 is shown, in which an already cut pipe 20 through the fixed clamping unit 24 is clamped in the bending machine and thus the pipe 20 stands still while the bending unit 2 . 3 emotional. In this case, the individual IR fields generating heaters 9.1 . 9.2 . 9.3 . 9.4 can be removed from the bending area. With the hinged design 11 can the heater 9 be opened to the pipe 20 to be placed or to be removed from the tube area. Is or are the heaters 9.1 . 9.2 . 9.3 . 9.4 around the pipe 20 positioned, it closes and starts the heating process. For positioning, the heating device (s) may be integrated into a machine system or mounted on a robot system.

For the continuous bending system concept, which in relation to the 1 . 2 . 3 and 6 has been described, additional heating areas are conceivable. In this process, the IR path with the heating devices takes place downstream of the process 9 in the area of the short distance of the axial sleeve 8th a further temperature control over the same (The arrow head V _a shows the feed direction of the tube 20 at). Here is the axial sleeve 8th tempered, so that as little heat loss in the section of the pipe to be bent 20 until the actual bending point occurs. This may optionally be in the Temperierungsbereichen 9 . 8th , especially in the area of the axial sleeve 8th , Be a slight overheating above the eig. Deformation temperature of the plastic addition, so that the cooling over the bending distance is not too large and thus the deformability is limited.

Immediately after the bending unit 2 . 3 a cooling process is provided to prevent the re-deformation of the plastic in the flexurally soft state and thus to ensure the highest possible tolerance quality. Cooling the pipes 20 can take place in the bending systems according to the invention via three autonomously operating cooling systems: one for active external cooling and one for active internal cooling and one for passive or partially active cooling of the deformed pipe section.

The active external cooling takes place either via a commercially available annular nozzle 1 or via vortex nozzle cooling. Both systems are based on compressed air L _a as a cooling medium and are controllable. A variant with ring nozzle 1 is in 2 seen. Thereby the nozzle becomes 1 directly behind the freeform unit 2 . 3 set and the compressed air flow L _a immediately cools the pipe area, which is no longer through the mandrel 4 is supported. A corresponding active external cooling can be behind the bending unit 2 . 3 the bending equipment for cut pipes after 9 . 10 be set.

3 shows a variant in which the active external cooling of this area via a vortex tube 1 or more. In this case, the cold exhaust air jet L _a from a nozzle 1 , as shown, or applied by several nozzles via leads to the required locations.

In this way, of course, other cooling media can be used in addition to compressed air, which of course would make the vortex tubes unnecessary. For this purpose, a supply line and the control of the coolant supply are required.

If the implementation of the direct attachment of the cooling device to the bending unit is not possible, it is conceivable to mount the cooling device on a robot which is able to follow exactly the movements of the bending unit and guide the cooling device parallel to the bending unit that neither a collision of the two units with each other nor of the robot or the cooling device guided by it takes place with the tube.

The active internal cooling 5 . 6 of the FRP pipe 20 is done either via miniature vortex nozzles or via the supply of external cooling media and is like the external cooling controllable. The active internal cooling is not only for the continuous bending variant after 1 . 2 . 3 . 6 but equally related to 9 and 10 described bending systems for cut tubes (but not shown there) used.

When cooling via a vortex tube 6 will, as in 2 . 3 or 6 visible, the vortex tube 6 in the inner support tube 7 or the guide lance 7 in the area behind the mandrel 4 appropriate. The supply of the cooling air L _i then takes place via an elastic supply line 5 through the mandrel 4 therethrough. At the end of the thorn 4 opens the supply line 5 either freely via an opening or via a nozzle in the pipe interior, thus providing directly following the bend for internal cooling of the pipe.

A corresponding system, with omission of the vortex tube, can also be used to transport alternative cooling media. These are from the rear end of the machine through the entire support tube 7 through the supply line 5 led to the bending point.

The third possible cooling system for passive or partially active cooling of the deformed pipe section is from the gripper device 14 a robot that supports the deformed area. This is the tube 20 following the transformation by means of a gripper device 14 supported, as in 4 shown, can be tempered or can be completely un-tempered. For temperature control, for example, coolant lines 16 in the gripper 14 be integrated, so that the gripper is tempered by a cooling medium, and thus of the gripper 14 recorded pipe section is cooled. The gripper 14 can take up the pipe 20 by means of a hinge 17 be opened by a unfolding movement (arrows o). In the case of an untempered gripper device, a purely passive cooling takes place, in which only an undesired deformation of the bent pipe section is prevented by the gripper device.

This support by the tempered or untempered gripper device 14 remains during the entire following bending process of the pipe. Thus, the robot on which the gripper device must 14 present, all further movements of the tube 20 , which arise through the bending process, compensate with a proper movement (cf. 9j) or 10h ). This is to avoid that the still warm and malleable pipes deform by themselves due to the forces occurring after the bending process. Furthermore, this also prevents the phenomenon of springback.

With each newly created bending point a renewed support is required, ie for supporting the robot of the first bending point is in addition another robot is used, which supports the second bending point (see. 9k) and 10i ). If more bends are added, additional robots will be deployed for support. Subsequent to the bending process, these pipes are cut to length, if not done in advance, while retaining the support by the robots.

Through the use of robots 21 can, as in 8th sketched, the bending process also for cut-to-length pipes 20 be automated by robots 21 with grippers 14 in a bending machine 15 from which they are under the support of the bending point 20 ' through the robots 21 with grippers 14 be removed. A rail system 22 allows the concerted movement of the robots 21 in two directions x and y.

Following bending or cutting to length, the tube can be fed directly to a further processing process or, as in 8th to see for complete cooling in a transport gauge 23 be filed. At the same time, the bent pipe becomes the robot 21 on the teaching 23 placed and then by tensioners 23 ' during the apprenticeship 23 fixed. This is a possible deformation of the pipe during transport (via transport rails 22 ) completely stopped and it can be in the teaching 23 to cool completely and then stored or further processed.

Furthermore, with a bending system according to the invention, the post-deformation or online deformation of the pipe cross-sections is possible.

The device for post-deformation 2 can adhere to the bending sleeve 3 connect as in 2 and 3 represented, or in the bending sleeve 3 be integrated as in 6 to see. With the cross-section deformation device 2 can be post-deformations such. B. ovalizations or recesses realize at constant pipe circumferences.

The device for post-deformation 2 is in 5 in a) schematic plan view and b) partial sectional view along section line AA from a) and constructed as follows: An elastic inner ring 10 , consisting of a non-adhesive material or provided with a non-stick coating, forms the heart of the deformation device. This ring 10 is in rigid semicircular clamping shoes 11 clamped, which in turn to linear, hydraulic or pneumatic units 18 are coupled. Their control units 12 (only one of which is shown in the plan view) sit on a fixed ring 13 over which the deformation device 2 with the actual bending unit 3 can be connected. The control units 12 are individually controllable and move the clamping shoes 11 by means of linear, hydraulic or pneumatic units 18 in the radial direction towards or away from the center of the pipe. By this displacement, the elastic inner ring 10 Defines deformed and supported, thus providing a deformation die for the cross section of the tube.

Is such a Nachverformungsvorrichtung 2 in the bending unit 3 integrated, as in 6 represented, so is the bending mandrel 4 be shortened (the dashed line member is omitted this variant), so that a deformation is possible and not by the bending mandrel 4 is hampered.

In a bending system designed according to the invention, it is not absolutely necessary for the bending unit to be integrated in the machine in the form of a bending sleeve; it can also be controlled by a robot. The bending takes place on the same principle as in the standard bending machine, the only difference is that the bending head or the bending sleeve is controlled by an external robot.

For optimum bending results with a FRP pipe, internal support during the forming process is required. This is a bending mandrel 4 used in the 2 . 3 and 6 can be seen. The most common form of deformable mandrels 4 form the spines 4 , which can be produced with different limb shapes and with a wide, narrow and very narrow limb distance. These include the Schupeltorn, which represent a special form of a narrow arthroplum. In a Schuppendorn the limbs are arranged like scales like a partial overlapping.

Conventional mandrels 4 However, they are not optimal, since undercuts or depressions in the bent tube section result from the penetration of the deformable fiber matrix material into the recesses between the links. In contrast to bending metal pipes, it is possible to dispense with metallic mandrel systems because completely different forces occur. In 7 are seven different mandrel variants a) to g) shown, which can be used in a bending system according to the invention and avoid the formation of undercuts or depressions, as they arise through the common mandrels. This is the bending mandrel 4 formed at least on its surface by an elastomeric material. The elastomer used must of course be suitable for the temperature range used in the bending process.

A first simplest variant, shown in 7a) looks forward to the bending mandrel 4 from a massive full elastomere body 40 to build. Also made of full elastomer depending on the possible degree of deformation of the mandrel 4 also as a hollow tube 40 ' ( 7b ). In this case, pay attention to a sufficient wall thickness, so that an ovalization of the mandrel 4 during forming as low as possible. To the wear of the thorn 4 At its peak, it is possible in this area a made of plastic or ceramic or a metallic nose 41 to install. For this purpose, different attachment variants may be provided, as in the 7a) and b) exemplified.

7c) shows a bending mandrel 4 making an elastomeric hose cover 42 over a common mandrel 43 having. The problem of the undercuts is bypassed by over the arthrophe 43 a thin elastomer hose 42 is pulled. Although this can still lead to low sinking, this hose prevents that the fiber matrix system can push behind the individual members and when pulling out the dome 4 or when pushing the pipe 20 is damaged. Thus, a damage to the fiber-matrix system is prevented and it can simultaneously on the already existing mandrels 43 be resorted to.

The elastomer hose cover 42 preferably has such a wall thickness and a stability that it allows only a very small image of the limbs to the outside, while it is thin enough at the same time to allow the widest possible deformation range, without causing wrinkles or damage.

The hose 42 can be closed according to a condom, open at the back and closed in front, over the entire mandrel 43 can be pushed, and then can be clamped at the open end. Alternatively, the elastomeric coating 42 be clamped as a hose section with two open ends in the front and rear area. In the elastomeric coating 42 Here, for the subsequent stretching of the fibers, a chamber system can be integrated, which in connection with 7f) is explained in more detail.

It was also discovered that one as a bending mandrel 4 used twisted rope 44 does not deform when bent but retains its cross-section. 7d) shows a section of such a bending mandrel, which consists of a rope core 44 that exists with an elastomeric shell 42 is provided, otherwise the surface of the core 44 would be charged too much in direct contact. A bending mandrel 4 based on a rope core 44 can be executed in several variants.

As with the full-elastomer bending mandrels, the bending mandrels can also be used 4 that has a rope core 44 comprise, in its front end to reduce wear an attached nose.

7e) shows a variant in which for better inherent stability and for better handling a thin adjustable link element system 45 in the rope core 44 is introduced. This link chain 45 serves to increase the inherent rigidity of the rope core bending mandrel 4 This ensures uncomplicated assembly of any machine, whether from the front or the rear. Like the rope core bending mandrel 4 out 7d) also has the in 7e) shown bending mandrel 4 an elastomeric shell 42 on.

In the 7f) variant shown relates to the design of the elastomer shell 42 ' which is at least two parts and consists either of chamber systems or of a complete division. So has the elastomeric shell 42 ' at least one chamber 46 on, which expands by introducing a pressure medium and thus the circumference of the mandrel 4 can be increased. This effect serves to tension the fiber composite and prevents unstretched fibers.

In this case, as already mentioned, a fully divided casing, that is a double-walled hose whose chamber formed by the double walledness is closed at one end, can be used, or else an elastomer casing with several chambers. The latter has the advantage that you can selectively inflate areas by the supply of the pressure medium only in certain chambers and thus can stretch at defined locations, the fibers in a defined direction.

An elastomer shell of this type can also be used for the mandrel variants with mandrel ( 7c ) and the cable core with twisted link chain ( 7e ) are used.

In the 7g) shown variant of a bending mandrel according to the invention 4 consists of an elastomer hose 42 with integrated reinforcement by a coil spring 47 , preferably of metal. The helical spring is used 47 in addition, a collapse of the pipe 20 to prevent during bending. Furthermore, it is conceivable, via this metal spring 47 to heat. The elastomer shell 42 serves to embed the coil spring core 45 and to ensure a sufficiently smooth surface. Around the bending mandrel 4 and with it the pipe 20 lend extra stability, can in the hollow interior of the bending mandrel 4 also a pressure medium are introduced. Even with this mandrel variant, it makes sense to attach a wear-reducing nose on the mandrel tip.

Another useful bending mandrel 4 based includes a shovel 43 ' who in 7h) as outlined, for example, by the company Ludwig Weber GmbH, Prisdorf, Germany, is outlined. In such a Schuppendorn 43 the inflow of the material between the members due to the shape of the limbs and their arrangement is prevented. Such a shovel 43 ' However, as in 7h) shown with an elastomeric shell 42 be provided.

In addition to the bending mandrels newly designed with elastomer, it is provided that the entire mandrel system, comprising the mandrel and the guiding lance, can be tempered. The temperature control can take place via liquid temperature control or heating cartridges. Liquid tempering not only heats up but also cools the system. The aim of the temperature control is to accelerate the heating of the FRP pipe and to minimize the heat loss via heat conduction. Temperatures in the range of 80-100 ° C are considered sufficient for this purpose, since it is not intended to completely heat the tubes over the temperature of the mandrel system; the temperature-controlled mandrel system serves only to support the actual heating via the IR radiators of the heating device (s).

Next, the invention provides the friction of the lance 7 in the FRP pipe. For this purpose, the lance 7 be provided with lubricious coatings such as Teflon. Furthermore, measures to reduce friction can be provided, with which the contact surface of the lance 7 is reduced to the pipe. This can for example be about slight heels 7.1 or recesses 7.2 by special cross-sectional shapes of the lance 7 take place, see 13a) to c). At the lance 7 with paragraphs 7.1 ( 13a ) the contact surface is only through the heels 7.1 formed while the recesses 7.2 in 13b) and c) reduce the contact area.

In a variant with heels 7.1 , in the 14 For ease of interchangeability, if the slide coating becomes worn instead of coating the entire lance 7 here exchangeable sliding elements 7.1 be used. These sliding elements 7.1 be via grooves on the actual lance 7 attached and then make a slightly larger diameter than the lance body 7 ' ready, which can be made of steel, for example. So the FRP pipe lies only on the sliding elements 7.1 on, thus sticking the plastic to the metal lance 7 prevent.

For handling after the bending process, it is advantageous to still selectively support the bent FRP pipes after leaving the bending unit, since the pipes have not reached final strength despite the intended cooling process and therefore especially with large overhangs and swivel paths and the resulting loads Deformations would tend. This support can, as already described, be done via robots with suitable grippers.

If the bending process is involved in an endless process following the production of the pipe, a device for cutting the pipes to length should be provided after the bending stage. The cutting process can also be performed by a robot unit due to the continuous feed of the endless tube, which tracks the intended separation point on the pipe a separator according to the feed.

The gripping units of the robots can be used both for the continuous process and for the bending of cut-to-length pipes, as described above, with internal cooling (cf. 4 ) be provided. As a result, the gripped pipe sections are additionally cooled, resulting in particular in these areas to a stiffening and thus slightly lower the necessary sensitivity of the robotic units.

According to the invention, the integration of the forming of a thermoplastic FRP pipe by bending and optionally post-forming of the cross-section into a continuous process is possible. In a corresponding embodiment (cf. 9 ), the transformation is possible in a continuous process, even without axial movement of the bending units. The support of the inner contour is achieved by the integration of novel mandrel systems, with which the quality of the fiber composite can be improved, especially in the bending area. By reducing the friction in the lance area, laminate distortions can be avoided by adhering the matrix. Optimized process times are ensured by integrated, controllable heating and cooling. By using the robot technology, a high degree of automation can be achieved. Furthermore, the self-deformations of the pipes can be prevented by supporting and fixing the pipes. The tube does not have to be rotated because the bending unit is freely deformable. The targeted partial warming enables energy savings. The optionally integrated post-deformation device allows with its adjustable die online deformation of the pipe cross-sections.

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 102005013700 B3 [0003]
• DE 20301138 U1 [0004, 0048]
• DE 10106741 C2 [0005, 0048]
• DE 102005013750 B3 [0041]

Claims (10)

Method for bending a thermoplastic fiber composite pipe ( 20 ), comprising the steps of: locally heating the thermoplastic fiber composite pipe ( 20 ) with at least one heating device ( 9 ) on at least one pipe section to be bent ( 20 ' ) to deformability, - removal of the heater ( 9 ) of the pipe section to be bent ( 20 ' ) and - bending the pipe ( 20 ) on the locally heated pipe section ( 20 ' ) by means of a bending unit ( 3 ), while inside pillars of the pipe section ( 20 ' ) with a bending mandrel ( 4 ), - cooling and mechanically supporting the bent pipe section ( 20 ' ) until the pipe section has hardened ( 20 ' ). The method of claim 1, comprising the step of: - deforming a cross-sectional shape of the tube ( 20 ) at least in the heated section ( 20 ' ) during bending or after bending with a cross-sectional deformation device ( 2 ). Method according to claim 1 or 2, wherein the inside supports by means of a robot ( 21 ) guided gripper device ( 14 ) and preferably during bending of the tube ( 20 ) on a second section ( 20 ' ) a compensating movement of the mechanically supported bent pipe section ( 20 ' ) he follows. Method according to at least one of claims 1 to 3, wherein the bending is carried out as free-form bending or rotational tensile bending or compression bending, and wherein the thermoplastic fiber composite pipe ( 20 ) - a continuously produced pipe string ( 20 ) which is moved during the execution of the method with a certain feed rate (V _a ), wherein the heating, bending, cooling and supporting at the moving at the feed rate (V _a ) portion ( 20 ' ), or - on a pipe cut to length ( 20 ). Bending plant ( 15 ) for carrying out the method according to one of claims 1 to 4 for a thermoplastic fiber composite pipe ( 20 ) comprising a bending unit ( 3 ) and a clamping unit ( 24 . 50 ), which are movable relative to each other, characterized in that the bending system ( 15 ) - at least one section to be bent ( 20 ' ) of the thermoplastic fiber composite pipe ( 20 ) movable heating device ( 9 . 9.1 . 9.2 . 9.3 . 9.4 ), - a bending mandrel ( 4 ) for inside support of the section ( 20 ' ), - at least one cooling device ( 1 . 5 . 6 . 16 ) for cooling the bent portion ( 20 ' ), - at least one of the bending unit ( 3 ) subordinate support device ( 14 . 21 ) for supporting the bent portion ( 20 ' ). Bending plant ( 15 ) according to claim 5, characterized in that the bending system ( 15 ) a deformation device ( 2 ) for changing the cross-sectional shape of the tube ( 20 ) at least in the bent portion ( 20 ' ), which the bending unit ( 3 ) or in the bending unit ( 3 ) is integrated. Bending plant ( 15 ) according to claim 5 or 6, characterized in that the bending mandrel ( 4 ) consists at least on its surface of an elastomeric material and preferably at its tip a nose ( 41 ), which consists of a plastic, a ceramic or a metal material has, wherein preferably the mandrel ( 4 ) - a solid full elastomer bending mandrel ( 40 ) or a bending mandrel ( 4 ) made of a full elastomer hollow tube ( 40 ' ), or - a mandrel ( 43 ) or a Schuppendorn ( 43 ' ) with an elastomer shell ( 42 ), or - a cable core ( 44 ) with an elastomer shell ( 42 ), or - a cable core ( 44 ) or a mandrel ( 43 ) or a Schuppendorn ( 43 ' ) with an elastomer shell ( 42 ) comprising at least one expandable chamber ( 46 ), or - one in a cable core ( 44 ) twisted link chain ( 45 ) and an elastomer shell ( 42 ), or - one in an elastomeric tube ( 42 ) embedded coil spring ( 47 ), which is preferably made of metal. Bending plant ( 15 ) according to at least one of claims 5 to 7, characterized in that the at least one cooling device ( 1 . 5 . 6 . 16 ) - a device for active external cooling, preferably a cooling ring ( 1 ) or a vortex nozzle ( 1 ), that of the bending unit ( 3 ) or the deformation unit ( 2 ), - a device for active internal cooling, preferably in the FRP tube ( 20 ) arranged vortex tube ( 6 ) from which a supply line ( 5 ) through the bending mandrel ( 4 ), which are included in the 20 ' ), and / or - a device for passive or partially active cooling, preferably by a device in a gripper device ( 14 ) integrated cooling device, comprising preferably cooling lines ( 16 ), wherein the gripper device ( 14 ) preferably from a robot ( 21 ) and particularly preferably that of the bending unit ( 3 ) subordinate support device ( 14 . 21 ). Bending plant ( 15 ) according to at least one of claims 5 to 8, characterized in that the heating device ( 9 . 9.1 . 9.2 . 9.3 . 9.4 ) a plurality of IR emitters ( 29 ) in a housing around the pipe ( 20 ) are arranged, and wherein the heating device ( 9 . 9.1 . 9.2 . 9.3 . 9.4 ) in a longitudinal direction (V _a , v ₂ , v _b ) along the tube ( 20 ) and / or in a direction (s) is movable perpendicular thereto, one perpendicular to the tube ( 20 ) movable heating device ( 9 . 9.1 . 9.2 . 9.3 . 9.4 ) comprises an openable housing. Production line for bent, thermoplastic fiber composite pipes ( 20 ), comprising a bending machine ( 15 ) according to at least one of claims 5 to 8, characterized in that the bending system ( 15 ) of a manufacturing plant ( 50 ) for the thermoplastic, continuous fiber composite pipes ( 20 ), the manufacturing plant ( 50 ) preferably a pultrusion plant ( 50 ) or a tape-laying device, and wherein the clamping unit by the manufacturing plant ( 50 ) is formed, and the bending system ( 15 ) in relation to the manufacturing plant ( 50 ) along the feed rate (V _a ) of the tube due to the manufacturing process ( 20 ) is movable.

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