Bending method for bending a composite bar

Abstract

A bending method and a bending device, wherein a composite bar comprising a bundle of reinforcing fibres embedded in a polymer matrix is bent at a bending point. To make it bendable, the composite bar is heated locally at the bending point using an ultrasonic device with a sonotrode. After the bending point has been heated, an infeeding movement between the composite bar and the sonotrode is used to deform a region of the composite bar at the bending point to create a deformed portion of which the outer dimensions are different from the outer dimensions of the bar portions of the composite bar adjoining the bending point. The two bar portions are then moved or angled away in relation to one another, and so the composite bar is curved at the bending point. Once the desired bending has been achieved, the composite bar is cured at the bending point.

Claims

1. A bending method for bending at least one composite bar (11) at a bending location (21) that comprises a reinforcement fiber bundle (15) with multiple reinforcement fibers (14) embedded in a cured plastic matrix, the method comprising the following steps: arranging a sonotrode (24) of an ultrasonic device (22) at the bending location (21), wherein two bar sections (11a) of the at least one composite bar (11) that adjoin the bending location (21) extend in a first spatial direction (x), heating a plastic matrix (M) of the at least one composite bar (11) at the bending location (21) by coupling ultrasonic waves in the at least one composite bar (11) at the bending location (21), prior to bending the at least one composite bar (11), deforming the at least one composite bar (11) for formation of a deformed section (37) at the bending location (21) by an infeed movement between the sonotrode (24) and the at least one composite bar (11) in a second spatial direction (y) that is orientated radial to a bend that is to be created at the bending location (21), bending the at least one composite bar (11) at the bending location (21), curing the plastic matrix (M) at the bending location (21).

2. The bending method according to claim 1, wherein an orientation of the bar sections (11a) of the at least one composite bar (11) remain unchanged relative to each other during the formation of the deformed section (37).

3. The bending method according to claim 1, wherein the deformed section (37) of the at least one composite bar (11) comprises a width (bz) in a third spatial direction (z) that is larger than a dimension (az) in the third spatial direction (z) of the bar sections (11a) adjoining the bending location (21), wherein the third spatial direction (z) is orientated orthogonal to the first spatial direction (x) and the second spatial direction (y).

4. The bending method according to claim 1, wherein the deformed section (37) of the at least one composite bar (11) has a thickness (dy) in the second spatial direction (y) that is smaller than a dimension (ay) in the second spatial direction (y) of the bar sections (11a) adjoining the bending location (21).

5. The bending method according to claim 1, wherein the at least one composite bar (11) has at the bending location (21) a bend inner side (BI) with an inner curvature and with reference to a center axis of the at least one composite bar (11) an opposite bend outer side (BA) with an outer curvature, wherein the inner curvature of the at least one composite bar (11) is larger than the outer curvature and wherein none of the reinforcement fibers (14) have a curvature at the bending location (21) that is larger than the inner curvature.

6. The bending method according to claim 1, further comprising emitting ultrasonic waves from the sonotrode (24) at least during phases during the infeed movement for formation of the deformed section (37) and/or during bending.

7. The bending method according to claim 1, further comprising supplying energy by a further energy source (44) at least during phases to the at least one composite bar (11) at the bending location (21) during bending.

8. The bending method according to claim 1, further comprising feedback controlling at least one of the following control parameters during the formation of the deformed section (37) and/or during bending: an ultrasonic energy output during the infeed movement and/or during bending, a time duration during which ultrasonic waves are emitted during the infeed movement and/or during bending, a power of the emitted ultrasonic waves, a temperature of the at least one composite bar (11) at the deformed section (37) or at the bending location (21), a pressure force between the sonotrode (24) and the at least one composite bar (11), a position of the infeed movement, a bend or angle position of the bar sections adjoining the bending location.

9. The bending method according to claim 1 further comprising omitting the emission of ultrasonic waves by the sonotrode (24) during the infeed movement for formation of the deformed section (37) and/or during bending.

10. The bending method according to claim 1, further comprising feedback controlling at least one of the following control parameters of during the formation of the deformed section (37): a relative position between the sonotrode (24) and the at least one composite bar (11), a velocity of the infeed movement, an acceleration of the infeed movement.

11. The bending method according to claim 1, wherein bending is carried out about a curved sonotrode surface (27) of the sonotrode (24), wherein the sonotrode surface (27) is curved about at least one axis that extends parallel to a third spatial direction (z), wherein the third spatial direction (z) is oriented orthogonal to the first spatial direction (x) and the second spatial direction (y).

12. The bending method according to claim 11, wherein the sonotrode surface (27) is in addition curved about at least one axis that extends parallel to the first spatial direction (x).

13. The bending method according to claim 1, further comprising keeping the sonotrode (24) stationary during bending.

14. The bending method according to claim 1, further comprising moving the sonotrode (24) in the second spatial direction (y) during bending.

15. The bending method according to claim 1, further comprising supplying a cooling medium (C) to the bending location (21) for curing the at least one composite bar (11).

16. The bending method according to claim 15, further comprising contacting the at least one composite bar (11) at the bending location (21) with a component within which a cooling medium flows and/or contacting the composite bar (11) directly with the cooling medium (C).

17. The bending method according to claim 1, wherein the plastic matrix (M) of the at least one composite bar (11) comprises a reversibly cross-linked plastic (K).

18. The bending method according to claim 1, wherein the plastic matrix (M) of the at least one composite bar (11) comprises a thermoplastic plastic (K).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Preferred embodiments of the invention can be derived from the dependent claims, the description and the drawings. In the following preferred embodiments of the invention are explained with reference to the attached drawings. They show:

(2) FIG. 1 a basic illustration of an embodiment of a device and a method for manufacturing a composite bar,

(3) FIG. 2 a composite bar in a schematic sectional perspective illustration,

(4) FIGS. 3-5 a schematic block-diagram-like embodiment of a bending method and a bending device in different phases during bending of a composite bar respectively,

(5) FIGS. 6-8 a schematic block-diagram-like illustration of a further embodiment of a bending method or a bending device in different phases during bending of a composite bar,

(6) FIG. 9 a modified embodiment of the bending device of FIGS. 6-8 in schematic block-diagram-like illustration,

(7) FIGS. 10-12 a schematic block-diagram-like illustration of a further embodiment of a bending method or a bending device in different situations during bending of a composite bar,

(8) FIGS. 13-15 an illustration of an embodiment of an ultrasonic device with a sonotrode in different views,

(9) FIG. 16 a schematic basic illustration of the deformation of a composite bar for formation of a deformed section,

(10) FIG. 17 the composite bar of FIG. 16 in a schematic basic illustration after it has been bent at a bending location,

(11) FIG. 18 a cross-section through the deformed section of a composite bar of FIG. 16 according to the sectional line A-A in FIG. 16,

(12) FIG. 19 a cross-section through the bending location of the composite bar of FIG. 17 according to the sectional line B-B in FIG. 17,

(13) FIG. 20 a schematic basic illustration of a construction material body in perspective partly cut illustration and

(14) FIGS. 21-23 a schematic illustration of different exemplary shapes of constructional bodies in a top view respectively.

DETAILED DESCRIPTION

(15) FIG. 1 shows the principle configuration of a pultrusion device 10 for manufacturing of a composite bar 11. The pultrusion device 10 comprises a creel 12 with multiple bobbins 13. On each of the bobbins 13 a reinforcement thread or a reinforcement fiber 14 is wound. The number of reinforcement fibers 14 and thus the number of bobbins 13 can vary. The reinforcement fibers 14 commonly form a reinforcement fiber bundle 15. The reinforcement fibers 14 are unwound from the bobbins 13 and immersed in a bath 16 of at least one liquid plastic K. The at least one plastic K sticks to the outer surface of the reinforcement fibers 14 and/or saturates the reinforcement fibers 14.

(16) Subsequently, under formation of the reinforcement fiber bundle 15 the reinforcement fibers 14 are guided into a die 17 and are cured in the desired cross-sectional contour, particularly completely cured. During the complete curing a tensile force that is applied on the reinforcement fiber bundle 15 is also maintained in the cured condition. By means of a haul-off device 18 that can comprise driven rollers or drums, the cured bar material is supplied out of the die 17 and is separated by the separation tool 19 in desired lengths. The cut bar material forms the reinforcement bars 11.

(17) In the embodiment the reinforcement bars 11 have a circular cross-section (FIG. 2). It has to be noted that in modification thereof other arbitrary cross-sectional contours can be manufactured in the die 17.

(18) The at least one plastic K forms a plastic matrix M, in which the reinforcement fibers 14 or the reinforcement fiber bundle 15 is embedded (FIG. 2). The at least one plastic K can be a thermoplastic plastic and/or a reversibly cross-linked plastic.

(19) A first embodiment of a bending device 20 is illustrated in FIGS. 3-5. The bending device 20 is configured to bend the composite bar 11 at a bending location 21. Prior to the bending at least the two bar sections 11a that are arranged at opposite sides of the bending location 21 extend along a common straight line G. In the embodiment illustrated here, the composite bar 11 does not have another bending location such that it completely extends along the common straight line G. The straight line G is orientated parallel to a first spatial direction x.

(20) The bending device 20 comprises an ultrasonic device 22 with an ultrasound source 23 as well as a sonotrode 24. The ultrasound source 23 creates ultrasonic waves that can be coupled into the composite bar 11 at the bending location 21 by means of a sonotrode 24 and that locally heat the composite bar 11 at the bending location 21.

(21) An embodiment of the ultrasonic device 22 is illustrated in FIGS. 13-15. The sonotrode 24 extends in a third spatial direction z that is orientated orthogonal to the first spatial direction x from a first end 25 to an opposite second end 26. At one of the two ends 25, 26 and, for example, at the first end 25 the sonotrode 24 is connected with the ultrasound source 23. The ultrasonic device 22 has thus a substantially L-shaped form. The ultrasound source 23 is only highly simplified illustrated in the drawing by the surrounding housing part that is connected with the sonotrode at the first end 25. Originating from the first end 25 the housing of the ultrasound source 23 substantially extends in a second spatial direction y away from the sonotrode 24. The second spatial direction y is orientated orthogonal to the first and the third direction x, z.

(22) The sonotrode 24 has a sonotrode surface 27. According to the example, the sonotrode surface is located at the outside in a front region of the sonotrode 24 that forms an end region of the sonotrode 24 with view in the second spatial direction y. The sonotrode surface 24 is curved about at least one axis, wherein this at least one axis extends parallel to the third spatial direction z. The curvature of the sonotrode surface 27 can be constant such that a constant radius of curvature is formed. The curvature can also comprise varying radii or amounts of curvature.

(23) In addition to this curvature about the at least one axis extending in the third spatial direction z, the sonotrode surface 27 can comprise a further curvature that is illustrated in dashed lines in FIG. 13. Due to this additional curvature, the sonotrode surface 27 can also curve about at least one axis that is orientated parallel to the first spatial direction x. In doing so, spherical or aspherical sonotrode surfaces 27 with curvature extensions in two spatial directions can be provided.

(24) As it can be revealed, particularly from FIGS. 13 and 15, the sonotrode 24 has a section adjoining the second end 26, in which the composite bar 11 can be bent without the bending being hindered by the geometry or the three-dimensional shape of the bent composite bar 11 or by the ultrasound source 23. In FIG. 13 a multiple bent composite bar 11 is illustrated by a dashed dotted line only as an example and in a schematic manner. If multiple bends are created at one composite bar 11 subsequently at different bending locations 21, a bend section of the composite bar 11 can extend over the sonotrode 24 at the side opposite of the sonotrode surface 27. In doing so, multiple bend three-dimensional shapes or extensions of the composite bar 11 can be created without being hindered by the ultrasound source 23.

(25) The embodiment of the ultrasonic device 22 illustrated in FIGS. 13-15 can be used in all of the embodiments of the bending device 20.

(26) A support device 31 is also part of the bending device 20. The support device 31 comprises at least one support body 32, wherein each support body 32 comprises a support surface 33. The support surface 33 is located at the side of the support device 31 facing the ultrasonic device 22 and is respectively configured to support at least a section of the composite bar 11.

(27) The support surface 33 of the at least one support body 32 is configured to at least partly reflect the ultrasonic waves. The ultrasonic waves passing through the composite bar 11 are as far as possible completely reflected back into the composite bar 11 at the side opposite the sonotrode 24. In doing so, according to the example, standing ultrasonic waves are formed between the sonotrode 24 and the support surface 33. The reflection results in a quicker provision of the bendability at the bending location 21. The support surface 33 or the at least one support body 32 consists, e.g. of a reverberant material that reflects a high proportion of the ultrasonic waves at the boundary layer toward the composite bar 11.

(28) By means of a axis arrangement that is not illustrated in detail, an infeed movement in the second spatial direction y can be carried out between the sonotrode 24 and the support device 31. In the embodiment this movement is created by a linear movement of the sonotrode 24 and according to the example the ultrasonic device 22. Additionally or alternatively, also the support device 31 could be linearly moveable in the second spatial direction y. In the embodiment described here such a linear movement of the support device 31 in the second spatial direction y is not provided.

(29) In the embodiment of the bending device 20 illustrated in FIGS. 3-5 at least some or all present support bodies 32 of the support device 31 are moveable relative to each other and according to the example, two support bodies 32 are pivotably arranged about an axis extending in the third spatial direction z. These two support bodies 32 can be connected to each other, e.g. via a swivel joint 34. Such a direct connection is, however, not required. The two support bodies 32 could also be separately moveably and/or pivotably arranged each at a device.

(30) The bending device 20 according to FIGS. 3-5 operates as follows:

(31) First, the composite bar 11 is arranged at the support device 31 or the support surfaces 33 of the support bodies 32. Subsequently the sonotrode 24 is brought into contact with the composite bar 11. Thereby the pressure force between the sonotrode 24 and the composite bar 11 can be controlled or feedback controlled. By means of the ultrasound source 23 ultrasonic waves are created and coupled into the composite bar 11 at the bending location 21, at which the sonotrode surface 27 abuts against the composite bar 11, whereby it is locally heated at the bending location 21 (FIG. 3).

(32) Following and/or concurrently with the injection of the ultrasonic waves an infeed movement of the sonotrode 24 relative to the support device 31 occurs, whereby the sonotrode surface 27 deforms the composite bar 11 at the bending location 21 and thus forms a deformed section 37 at the composite bar 11 (FIG. 4). This situation is also schematically illustrated in FIG. 16. The deformed section 37 obtains a depression 38 in the shape of a fillet or groove due to the pressing of the sonotrode 24 or the sonotrode surface 27. In case of a curved support surface 33, in this method step a curvature is already created at the composite bar 11, wherein the side of the composite bar 11 abutting at the support surface 33 obtains a curvature that corresponds substantially to the curvature of the support surface 33.

(33) In FIG. 18 a cut through the deformed section 37 is shown and it can be perceived that the deformed section 37 of the composite bar 11 comprises a width bz in the third spatial direction z that is larger than the dimension az in the third spatial direction z of the bar sections 11a adjoining the deformed section 37. Concurrently a thickness dy of the deformed section 37 in the second spatial direction y is smaller than a dimension ay of the bar sections 11a adjoining the deformed section 37. Due to this change of the cross-sectional contour or the dimensions in the deformed section, the reinforcement fibers 14 are displaced from a posterior bend inner side BI of the composite bar 11 toward a posterior bend outer side BA. In doing so, a tension is maintained on the reinforcement fibers 14, if the composite bar 11 is bent during the further process at the bending location 21. The reinforcement fiber bundle 15 remains straight at the bending location 21 in direction of the extension of the composite bar 11 so to speak and does not comprise or does only comprise negligible corrugations or kinks.

(34) The infeed movement for formation of the deformed section 37 at the bending location 21 is schematically illustrated in FIG. 4. The infeed movement can be carried out in a controlled or feedback-controlled manner. During the infeed movement the relative position of the sonotrode 24 relative to the composite bar 11 or the support device 31, the velocity of the infeed movement or the sonotrode 24, the acceleration of the infeed movement or the sonotrode 24 or a combination of these control parameters can be feedback controlled. During the execution of the infeed movement the emission of ultrasonic waves by the ultrasonic device 22 can be omitted. It can also be advantageous to emit at least temporarily or during phases ultrasonic waves in order to maintain the deformability of the composite bar 11 at the bending location 21, because the composite bar cools down due to convection from the bar outer surface.

(35) The bending device 20 comprises at least one bending tool that is configured for bending the composite bar 11 at the bending location. In the embodiment according to FIGS. 3-5 three bending tools are present: A first bending tool 41 is formed by the sonotrode 24 or the sonotrode surface 27 and a second bending tool 42 and a third bending tool 43 are respectively formed by one of the two support bodies 32. For bending the composite bar 11 at the bending location 21 the two support bodies 32 forming the second and the third bending tool 42 and 43 are inclined or pivoted relative to each other, whereby the two bar sections 11a abutting against the support surfaces 33 are angled relative to each other (FIG. 5). The first support tool 41 formed by the sonotrode 24 supports the composite bar at the bend inner side at the bending location 21. The inner curvature of the bend inner side is defined by the sonotrode surface 27.

(36) During bending energy can be supplied to the composite bar 11 at the bending location 21 in order to maintain the bendability, if the bar cools down, e.g. due to convection, radiation or thermal conduction. For this the ultrasonic device 22 can at least temporarily or during phases emit ultrasonic waves and couple ultrasonic waves into the composite bar 11. Preferably a support surface 33, at which the composite bar 11 is supported at the bending location 21 is formed in a concave manner, particularly formed in such a concave manner that the curvature corresponds to the outer radius of curvature of the deformed or bent composite bar 11. In doing so the optional noise coupling is as efficient as possible. Alternatively or additionally, a separate energy source 44 can be provided that supplies heat to the composite bar 11 and the bending location 21 in order to maintain a temperature at the bending location 21 that guarantees a bendability of the composite bar 11. For example, the additional energy source 44 can be a thermal radiation source, like an infrared radiator.

(37) Following the bending of the composite bar, the composite bar 11 is again cured at the bending location 21. According to the example, this is carried out by cooling of the plastic matrix M at the bending location 21. The cooling can be accelerated, if a cooling medium C is supplied to the composite bar 11 at the bending location 21. According to the example, the bending device 20 comprises a cooling device 45 by means of which the cooling medium C can be dispensed on the composite bar 11 at the bending location 21. The cooling device 45 can, for example, create and dispense an atomized spray or a gas or air flow as cooling medium C.

(38) Alternatively or additionally, at least one component of the bending device can be cooled, e.g. the sonotrode 24 and/or the support device 31 and/or at least one of the support bodies 32 and/or at least one bending tool 41, 42, 43. For example, cooling media channels can extend through a cooled or coolable component, through which a cooling media can flow during cooling. The time duration for cooling can thus be decreased.

(39) The additional energy source 44 and the cooling device 45 are optional.

(40) In the embodiment shown in the FIGS. 3-5 the support surfaces 33 of the support bodies 32 have a length in extension direction of the bar sections 11a such that the respectively assigned bar section 11a is not only supported in a point-like manner at a location, but along a longitudinal area and preferably its total length up to the bending location 21. The support bodies 32 can be configured in a plate-like and/or bar-like shape. The support surface 33 can be formed by the inner surface of a groove or flume, in which the respectively assigned bar section 11a is located. For example, each bar section 11a can abut at the groove flanks of a groove of the support surface 33 and can thus be moved in a guided manner along the groove extension during bending.

(41) In FIGS. 6-8 a further embodiment of the bending device 20 is illustrated. The configuration substantially corresponds to that of the embodiment according to FIGS. 3-5 such that reference can be made to the description above. The main difference exists in the configuration of the support device 31 as well as the bending tools. The support device 31 comprises multiple and according to the example, three stationary support bodies 32, each having a planar support surface 33. The support surfaces 33 of multiple or all present support bodies 32 can extend in a common plane.

(42) Also in this embodiment the first bending tool 41 is formed by the sonotrode 24. The second and the third bending tool 42, 43 are separately formed from the support device 31 and can be formed by a respective rod or roller. A central support body 32 is arranged in alignment with the sonotrode 24 on the opposite side of the composite bar 11 and supports the composite bar 11 at the bending location 21 against the pressing force of the sonotrode 24. On both sides of the central support body one bending tool 42 or 43 is arranged respectively with view in the first spatial direction x. For bending the bending tools 42, 43 move relative to the first bending tool 41 (sonotrode 24), e.g. in the second spatial direction y or within a plane spanned by the first and the second spatial directions x, y. In doing so, the composite bar 11 is bent about the sonotrode surface 27 at the bending location 21.

(43) Apart therefrom the process of the method corresponds to that explained with reference to FIGS. 3-5 such that reference can be made to the description above.

(44) The adjustment of the method parameters during the bending method depend on the dimension of the material of the composite bar 11.

(45) The total duration for heating the bar by ultrasound, the formation of the deformed section 37 and the bending has an amount of about 10-20 seconds (in case of a composite bar with about 55% fiber volume percentage and a diameter of 8 mm). The infeed of the sonotrode can have an amount of 1 mm/sec.

(46) The emission of ultrasonic waves is started in one embodiment, if a trigger threshold is reached with which the sonotrode presses against the composite bar 11. The trigger threshold can have an amount of, e.g. 50 Newton. The pressure with which the sonotrode 24 is pressed against the composite bar 11 can be limited to a maximum value, e.g. to a value of 400 Newton.

(47) In one embodiment the emission of ultrasonic waves is stopped, if a total energy amount of ultrasonic energy has been output in total, e.g. 2600 Joule (in case of a composite bar with about 55% fiber volume percentage and a diameter of 8 mm).

(48) The present bending tools 41, 42, 43 apply a predefined force on the composite bar 11. As far as the bendability at the bending location 21 is sufficient, the bending of the composite bar 11 at the bending location 21 thus starts.

(49) According to the example, the cooling of the bar is started as soon as the threshold for the total amount of energy is reached. Without supplying a separate cooling medium C, the cooling duration, until the composite bar 11 is bend-resistant again at the bending location 21, can be about 20 seconds (in case of a composite bar with about 55% fiber volume percentage and a diameter of 8 mm). This duration can be shortened by supplying a cooling medium C inside or outside a component of the bending device 20.

(50) The process parameters are adjusted depending on the configuration of the bending device 20, the plastic of the composite bar 11 (amorphous/semi-crystalline, damping factor or mechanical loss factor, softening temperature, melting temperature, glass transition temperature, etc.), the type of the used fibers, the percentage of the fibers from the volume or the mass of the composite bar, the diameter of the composite bar, etc.

(51) FIG. 9 illustrates schematically a modification of the embodiment of the bending device 20 of FIGS. 6-8. There the central support body 32 has no completely planar support surface 33, but the support surface 33 comprises a concave support cavity 48. The curvature of the concave support cavity 48 corresponds substantially to the outer curvature that the composite bar 11 has at the bending location 21 after formation of the deformed section 37 or that it should have at the end of the bending. By or after the formation of the deformed section 37 and/or during bending of the composite bar 11, the composite bar 11 engages the support cavity 48 at the bending location 21 and is two-dimensionally supported by the support cavity 48.

(52) A further embodiment of a bending device 20 is illustrated in FIGS. 10-12. In this embodiment a drum arrangement or roller arrangement 49 with multiple drums or rollers 50 serve for conveying the composite bar 11 in the desired position, such that the bending location 21 is arranged between the sonotrode 24 and a support body 32 of the support device 31. One of the two bar sections 11a remains engaged by the roller arrangement 49, if the deformed section 37 is deformed and the composite bar 11 is bent (FIGS. 11 and 12). In this embodiment the sonotrode 24 in turn forms the first bending tool 41. Different to the other embodiments, only one further bending tool is provided, namely the second bending tool 42 that is moveable relative to the first bending tool 41 in the second spatial direction y or in a plane spanned by the first spatial direction x and the second spatial direction y. The second bending tool 42 is analog to the preceding embodiment according to FIGS. 6-9 formed by a rod or a roller. The roller arrangement 49 is configured for clamping or retaining the composite bar 11 at one of the bar sections 11a, whereas the respective other bar sections 11a, whereas the respective other bar section 11a is engaged by the second bending tool 42 and is bent about the sonotrode surface 27. Instead of the roller arrangement 49 also another device for clamping of a bar section 11a could be present.

(53) Apart therefrom the bending device 20 as well as the executed method corresponds to the preceding embodiment so that reference can be made to the above explanation.

(54) An optional embodiment with an additional heating device 51 is schematically illustrated in FIG. 10. The additional heating arrangement 51 serves to preheat the composite bar 11 before it is transported in the position, in which it is deformed or bent. Such a heating device 51 can be present in all of the embodiments of the bending device 20. The heating of the composite bar 11 with the heating device 51 can be limited locally to a region that comprises the bending location 21.

(55) The specific embodiments described based on the drawings explain the invention as an example based on the bending of a composite bar 11. For bending of multiple composite bars 11 or a mesh body, the sonotrode surface 27 and/or the at least one support surface 33 and/or other parts of the bending device 20 can be configured with a respective length in the third spatial direction z. This applies for all of the embodiments. The function described based on one composite bar 11 applies accordingly for multiple composite bars 11 or a mesh body.

(56) FIGS. 17 and 19 schematically illustrate a bent composite bar 11. At the bending location 21 with view in the second spatial direction y the bend bar has a bend inner side BI having an inner curvature and facing away therefrom an opposite bend outer side BA having an outer curvature. The inner curvature and the outer curvature can have a constant amount or can have varying curvatures or varying radii along the extension of the bend. The bend inner side BI abuts at the sonotrode surface 27 during bending. The inner curvature is thus defined by the extension of the curvature of the sonotrode surface 27. The bend outer side BA abuts preferably at a support surface 33 during bending.

(57) At the bending location 21 the composite bar 11 has a thickness sy with view in the second spatial direction y and a width bz in the third spatial direction z. The width bz is larger than the width or the dimension az of the bar section 11a outside the bending location 21 in the third spatial direction z and is substantially as large as the width bz of the deformed section 37 or slightly smaller. The thickness or dimension sy in the second spatial direction y is smaller at the bending location 21 than the dimension ay of the bar section 11a outside of the bending location 21 and at least as large as the thickness dy of the deformed section 37 in the second spatial direction y. Due to this change in the cross-section, shape of the composite bar 11 at the bending location 21, the reinforcement fibers 14 remain stretched or under tension and do not provide corrugations due to creation of a bend in the region of the bend inner side BI. In doing so, the tensile strength of the composite bar 11 can be maintained.

(58) In all of the embodiments it is possible that ultrasonic waves are coupled into the composite bar 11 at the bending location 21 during the deformation for formation of the deformed section 37 and/or during the bending. In doing so, energy is supplied to the composite bar 11 and the bending location 21 of the composite bar 11 can correspond at least to a required minimum temperature in order to maintain the deformability or the bendability. In doing so, heat losses due to convection can be balanced. It can be provided that the temperature of the composite bar 11 at the bending location 21 is feedback controlled. It is also possible to feedback control a timer duration during which ultrasonic waves are coupled into the composite bar and/or an ultrasonic power of the emitted ultrasonic waves during deformation or bending. Also the total ultrasonic energy that is output during deformation or bending can be controlled or feedback controlled. Finally, also the pressure force between the sonotrode 24 and the composite bar 11 can be controlled or feedback controlled. Also a combination of the above-mentioned controls or feedback controls is possible.

(59) In FIGS. 20-23 a construction material body 55 with a reinforcement arrangement 56 is schematically illustrated respectively. The reinforcement arrangement 56 comprises one or more reinforcement bars 11. They are embedded in a construction material matrix 57 of the construction material body 55. The reinforcement bars 11 can form a mesh or another suitable two-dimensional or three-dimensional reinforcement arrangement 56. As is illustrated in FIGS. 22 and 23 depending on the form of the construction material body 55, it can be necessary or advantageous to bend one or more reinforcement bars 11 at one or more bending locations 21. This can be carried out in a factory building or at the location of the construction site with the bending method described above and the bending device 20 described above. By using the bending device 20 or by using the bending method, construction material body 55, at least one bent composite bar 11 can thus be manufactured.

(60) The invention refers to a bending method and a bending device 20, wherein a composite bar 11 having a reinforcement fiber bundle 15 embedded in a plastic matrix M is bent at a bending location 21. In order to enable the bendability, the composite bar 11 is locally heated at the bending location 21. An ultrasonic device 22 with a sonotrode 24 serves this purpose. After heating the bending location by an infeed movement between the composite bar 11 and the sonotrode 24, a region of the composite bar 11 at the bending location 21 is deformed to a deformed section 37, the outer dimensions of which are different from the outer dimensions of the bar sections 11a of the composite bar 11 that adjoin the bending location 21. Subsequently the two bar sections 11a are moved or angled relative to each other such that the composite bar 11 is curved at the bending location 21. Preferably the composite bar 11 is supported at the sonotrode 24. If the desired bend is reached, the composite bar 11 is cured at the bending location 21.

LIST OF REFERENCE SIGNS

(61) 10 pultrusion device 11 composite bar 11a bar section 12 creel 13 bobbin 14 reinforcement fiber 15 reinforcement fiber bundle 16 band 17 die 18 haul-off device 19 separation tool 20 bending device 21 bending location 22 ultrasonic device 23 ultrasound source 24 sonotrode 25 first end of the sonotrode 26 second end of the sonotrode 27 sonotrode surface 31 support device 32 support body 33 support surface 34 swivel joint 37 deformed section 38 depression 41 first bending tool 42 second bending tool 43 third bending tool 44 energy source 45 cooling device 48 support cavity 49 roller arrangement 50 roller 51 heating device 55 construction material body 56 reinforcement arrangement 57 construction material matrix ay dimension of the bar section in the second spatial direction az dimension of the bar section in the third spatial direction bz width of the forming section C cooling medium dy thickness of the forming section K plastic M plastic matrix S pivot axis x first spatial direction y second spatial direction z third spatial direction