Device and method for forming a blank made of fiber-reinforced thermoplastic

Abstract

Forming device (10) for a method for forming a flexible, rod-shaped blank (1) made of fiber-reinforced thermoplastic, the forming device (10) comprising: - a die (14) for receiving and forming the blank (1), with a forming area (14.1, 14.2) comprising a forming base area (14.2) against which the blank (1) is pressed in a forward direction (20.3), and a forming lateral area (14.1) against which the blank (1) is pressed in a first lateral direction (20.1) lateral to the forward direction (20.3), - a lateral punch (16) which is displaceable in the first lateral direction (20.1) for pressing the blank (1) against the forming lateral area (14.1) of the die (14), and - a forward punch (12, 16.2) for pressing the blank (1) against the mold base area (14.2) of the die (14), wherein the forward punch is designed i) in a separate embodiment as a forward-directed (20.3) a movable element separate from the lateral punch (16), or ii) in a unit design as a projection (16.2) of the lateral punch (16) extending in the first lateral direction (20.1); a clamping slide (14.3) designed as a rod, projecting from an opening in the lateral area (14.1) of the die (14); an elastic element (14.3) for resiliently supporting the clamping slide (14.3) against the base of the opening; a gripping device (17) for gripping the blank (1) at its ends; two press jaws for pressing the blank (1) at its ends; ejector pins extendable from the base area (14.2) of the die (14) for ejecting a product obtained from the blank (1) by forming; wherein a coordinate system is defined by three directions: i) the first lateral direction (20.1), ii) a second lateral direction (20.2) which relates to the forward direction (20.3) and to the first lateral direction (20.1) is perpendicular and along which a lateral coordinate runs, and iii) the forward direction (20.3),- wherein a first plane is defined by the first and second lateral directions (20.1, 20.1), and a second plane is defined by the second lateral direction (20.2) and the forward direction (20.3),- the forming device (10) comprising at least one of the following features:- the forming lateral area (14.1) of the die (14) extends in the first plane along a lateral contour and is preferably strip-shaped;- the lateral punch (16) has an end face (16.1) facing the forming lateral area (14.1) of the die (14), which preferably extends in the first plane along the lateral contour and is particularly strip-shaped, wherein preferably the forming lateral area (14.1) of the die (14) and the end face (16.1) of the lateral punch (16) are adapted to each other;- the Molded floor area (14.2) the die (14) extends along a height contour in the second plane and is preferably strip-shaped; - the forward punch (12, 16.2) has an end face (12.1) facing the mold base area (14.2) of the die (14), which preferably extends along the height contour in the second plane and is particularly strip-shaped, wherein preferably the mold base area (14.2) of the die (14) and the end face (12.1) of the forward punch (12, 16.2) are adapted to each other; - the projection (16.2) of the lateral punch (16) is, in the unit embodiment, funnel-shaped in a region facing the mold base area (14.2) of the die (14) in the first lateral direction (20.1); - the clamping slide (14.3) is slidably guided in the opening of the die (14) and through the elastic element (14.4) supported such that the blank (1) is between the lateral punch (16) and the clamping slide (14.3) is spring-loaded and clampable;- the gripping device (17) is designed to grip the blank (1) at its ends, whereby the blank (1) is displaceable with respect to the forming area (14.1, 14.2) of the die (14);- the press jaws are displaceable to each other along the second lateral direction (20.2) for pressing the blank (1) in the second lateral direction (20.2).

Description

The present invention relates to a forming device for a method for forming a flexurally soft, rod-shaped blank made of fiber-reinforced thermoplastic. The invention further relates to a method for forming a flexurally soft, rod-shaped blank made of fiber-reinforced thermoplastic.With fibers, mechanical, thermal and dynamic properties of thermoplastic polymers can be greatly improved. Long fiber-reinforced thermoplastics, for example, are distinguished by high rigidity with very good energy absorption capacity, which meets requirements of light construction in motor vehicles. The glass fibre reinforcement also brings about a marked increase in the notched impact strength and heat distortion resistance. Thus, rods of fiber reinforced thermoplastic are commonly used for load bearing structures in lightweight components of motor vehicles.However, during 3D forming of a rod made of fiber-reinforced thermoplastic, the problem frequently arises that the blank, i.e. the starting workpiece to be formed, is cut to an initial length before the start of the forming, which length changes to a real final length, which is greater or less than the desired final length as a result of the forming, so that length cut or waste is produced. This misassessment is a consequence of complex 3D forming processes which, in the case of the known forming devices, make it difficult to correctly estimate a length change of the blank which occurs during the forming.The problems associated with misassessing the final real length reduce the economic efficiency of the forming.DE 689 19 466 T2 discloses a method for producing screw-type fastening means from glass fiber-reinforced plastic.DE 33 36 467 C2 discloses a method for bringing about a crystallization of a material in a wall of an object.DE 10 2014 015 414 A1 discloses a method for producing a shell-shaped fiber composite component.DE 10 2012 202 653 A1 discloses a method for producing a fiber-reinforced plastic component.U.S. Pat. No. 8,535,042 B1 discloses a method for producing a flange component from a composite material.It is therefore an object of the present invention to eliminate or at least partially eliminate the above-described disadvantages during the forming of a blank made of fiber-reinforced thermoplastic. In particular, it is the object of the present invention to provide a method for forming a flexurally soft, rod-shaped blank made of fiber-reinforced thermoplastic and a forming device for a forming method, wherein the structure of the forming device is simplified and the economic efficiency of the forming method is improved.The above object is achieved by the independent claims. Accordingly, the object is achieved by a forming device having the features of claim 1 and by a forming method having the features of claim 2. Further features and details of the invention are evident from the dependent claims, the description and the drawings. Features and details which are described in connection with the forming device also apply in connection with the forming method and vice versa, so that with regard to the disclosure reference is or can always be made to the individual aspects of the invention in a mutually alternating manner.According to one aspect, the object is achieved by a forming device for a method for forming a flexurally soft, rod-shaped blank made of fiber-reinforced thermoplastic.For a description of the forming device and the forming method associated therewith, it is provided according to the invention to use a coordinate system. The coordinate system is defined by three directions: i) a first lateral direction, ii) a second lateral direction along which a lateral coordinate runs, and iii) a forward direction, which is preferably perpendicular to the first lateral direction and to the first lateral direction.This is a skew coordinate system. Optionally, a Cartesian coordinate system can also be used, in which the following correspondences preferably apply:first lateral direction=x-direction, x-axis,second lateral direction=y-direction, y-axis,Forward direction=z-direction, z-axis.According to the invention, two planes are defined in the coordinate system:a first plane determined by the first and second lateral directions, for example xy plane, anda second plane determined by the second lateral direction and the forward direction, for example yz plane.The first plane and the second plane can be skew to one another or perpendicular to one another.The blank can be a prefabricated workpiece or raw material, preferably a semi-finished product, which is formed into rod shape and is converted into a flexurally soft state by means of thermal or chemical treatment. In this case, flexurally soft means that the rod can be deformed or deformed with only a small amount of force. The rod shape is characterized by a length of the rod that is substantially greater than its lateral extent, wherein the rod i) may have a rectangular, square, round or oval cross-section and ii) may be straight or curved.The forming can be considered a production method in which the flexurally soft blank is specifically brought from the original shape into another shape without material being removed from the blank or being supplied to the blank. During the forming process, the cross section of the blank can possibly also be changed.The forming device comprises:a die for receiving and forming the blank, having a forming region comprising a forming base region against which the blank is pressed in a forward direction and a forming lateral region against which the blank is pressed in a first lateral direction lateral to the forward direction,a lateral punch movable in the first lateral direction for pressing the blank against the mold lateral portion of the die; anda forward punch for pressing the blank against the die base region of the die, wherein the forward punch is formed i) in a separate configuration as an element which is displaceable in the forward direction and separate from the lateral punch, or ii) in a unit configuration as a projection of the lateral punch projecting in the first lateral direction.The die can be designed as a rigid or immovable part of the forming device, wherein at least one movable part (lateral punch, forward punch) forms the blank by means of displacement relative to the die and pressing against the forming region of the die.The forming region of the die may comprise an elongate pressure plate having at least one contact surface with the blank, wherein the contact surface may press the blank against the lateral punch and / or forward punch and i) may be formed as a contact surface having a cross-sectional contour which is convexly shaped in the first plane, or ii) may comprise two contact surfaces which abut one another in each case with a shape which follows the elongate shape of the blank to be formed.In the separate embodiment, the forming device comprises two parts or punches that are movable independently of one another, namely the lateral punch that is displaceable in the first lateral direction and the forward punch that is formed separately from the lateral punch and is movable separately. By sequentially or simultaneously displacing the lateral punch and the forward punch, the blank can be pressed between the punches and the forming region of the die and thereby be formed.In the unit embodiment, the forming device comprises a movable part, namely the lateral punch which is displaceable in the first lateral direction and which has a projection projecting in the first lateral direction. In a maximally extended or displaced state of the lateral punch, the projection of the lateral punch has a pressure surface facing the blank, which pressure surface is at a defined distance from the mold base region of the die and thus forms a rod-shaped pressing space for the blank, between a lateral end face of the lateral punch, the pressure surface of the lateral punch projection and the mold base region of the die.In the unit embodiment, the lateral punch, when being displaced in the first lateral direction toward the die molding region or the blank, may enclose the blank i) between the lateral end face of the lateral punch and the die molding lateral region of the die, and ii) between the pressing face of the lateral punch protrusion and the die bottom region of the die, in the pressing space. During the lateral displacement of the lateral punch, the blank can thus be pressed in the first lateral direction and in the forward direction.Optionally, the forming region, if it comprises two contact surfaces abutting each other, can contribute to a pressing space formed between the end surface of the forward punch, the end surface of the lateral punch and the contact surfaces of the die forming region, into which the blank can be introduced and pressed by the punches.According to a further aspect, the object is achieved by a method for forming a flexurally soft, rod-shaped blank made of fiber-reinforced thermoplastic by means of the forming device described above, the method comprising:v1) determining a length change of the blank to be expected during the forming of the blank with respect to a defined initial length, for reducing or avoiding length waste,v2) cutting the blank to a final length = initial length + length change, andv 3) Forming of the blank by means of the forming device.The initial length may correspond to a roughly estimated length that the blank could have after forming; it may correspond, for example, to an extent of the forming device into which the blank is inserted for forming, or it may have a value based on experiences with changes in length as a result of forming by means of the forming device.The determination of the length change in step v 1) preferably means a computer-based calculation which is based on the structure of the forming plant and the dynamics of the forming. In this case, a CAD model of the forming plant can be used, wherein surfaces or elements which contact and / or guide the blank during forming, taking into account the geometry of the acting elements, make possible a realistic and precise simulation of the length change.In order to detect possible deviations between real and simulated length changes on the basis of parameters such as temperature and / or air humidity in the environment of the forming plant, first test runs can be carried out. Corrections of the simulated changes in length can be determined and quantified on the basis of the test runs.In order to determine the corrections, parameters involved in the test runs, such as, for example, type and cumulative life time of the forming device, material parameters of the blank, temperature, humidity, and measured deviations, on the other hand, can be systematically detected. The values of the parameters and the deviations can be supplied in the form of value series to an adaptive, self-learning system, for example a neural network, which learns the relationship between parameters and deviations, so that in real operation, with knowledge of the parameters, the changes in length determined by means of simulation are corrected reliably and realistic.The concept of forming device and forming method can be carried out more easily, quickly than known concepts and brings about the technical effect that it enables two-stage forming of the blank in one plane each: i) in the first plane by pressing the blank between lateral punch and mould lateral region of the die, and ii) in the second plane by pressing the blank between forward punch and mould base region of the die.A 3D forming can thus be carried out by two sequential 2D formings.The mentioned effect has the advantage that with the present method a simulation of a 3D forming and thus a determination of the length change of the blank caused by the forming is easier, less complicated and more precise. This is associated with the fact that two 2D simulations are less complex than a conventional 3D simulation and, connected therewith, the results of the 2D simulations are more realistic and / or the simulations require a lower overall computing effort.The present concept based on forming device and forming method enables a simplification of the tools and process sequences used, a reduction or even elimination of length waste and waste and thus an improvement of economic efficiency, cost efficiency and precision in 3D forming of rods made of fiber-reinforced thermoplastic.According to the invention, the lateral region of the die extends in the first plane along a lateral contour and is preferably strip-shaped. In particular, the lateral contour can have a functional course dependent on the lateral coordinate and / or the lateral contour can run in the first plane.The lateral contour described has the technical effect that the lateral contour has a 2D course. The mentioned effect has the advantage that a first of two 2D deformations can be implemented therewith, which together form the 3D deformation and can be simulated more easily and with higher precision compared to a conventional 3D deformation, so that the length change of the blank determined therewith and effected by the deformation is more realistic.According to the invention, the lateral punch has an end face facing the mould lateral region of the die, which preferably runs in the first plane along the lateral contour and is in particular strip-shaped. According to the invention, the mould lateral region of the die and the end face of the lateral punch are matched to one another and run complementarily to one another in order to thus laterally delimit the rod-shaped press space of the blank and advantageously to enable the lateral pressing and reforming of the blank in the first plane.According to the invention, the mold base region of the die runs in the second plane along a height contour. Preferably, the height contour can have a functional profile dependent on the lateral coordinate.The described height contour has the effect that it has a 2D course, which has the advantage that a second of two 2D deformations is realized therewith, which together form the 3D deformation, and corresponds to the advantage of the lateral contour already described.According to the invention, the forward punch has an end face facing the mold base region of the die, which preferably runs in the second plane along the height contour and is in particular strip-shaped. According to the invention, the mold base region of the die and the end face of the forward punch are matched to one another in order to thus delimit the rod-shaped pressing space of the blank on both sides in the forward direction and advantageously to enable pressing in the forward direction and forming of the blank in the second plane.This has the effect that, when the forward punch is displaced towards the die base region of the die, the rod-shaped pressing space, which is designed as an intermediate space, is formed between the end face of the forward punch, the end face of the lateral punch and the die base region of the die. The mentioned effect has the advantage that the blank, if it is located in the pressing space, can be pressed in the forward direction and / or the first lateral direction, whereby the blank can be shaped by means of a 2D shaping in the second plane and / or a 2D shaping in the first plane.In a preferred development of the invention, a lateral surface of the forward punch can run along the lateral contour. This has the effect that the rod-shaped intermediate space or pressing space for receiving the blank can thereby be formed, so that the blank can be pressed in the forward direction in the pressing space, wherein preferably an escape of the blank material due to the press pressure past the press ram is not permitted or prevented. The effect has the advantage that a material loss during the pressing of the blank in the pressing space is reduced or prevented.According to the invention, the projection of the lateral punch, in the unit embodiment, is funnel-shaped in a region facing the mold bottom region of the die, in the first lateral direction. The funnel-shaped form of the lateral punch has the effect that the projection of the lateral punch provides a still missing limitation for the pressing space already delimited in lateral regions and in a base region by means of displacement of the lateral punch in the first lateral direction. The effect has the advantage that by means of displacing a single element (lateral punch), a complete delimitation of the pressing space (lateral and in the forward direction) is formed and thereby the pressing and forming of the blank both in the first and in the second plane are made possible.According to the invention, the forming device in the separate embodiment comprises a clamping slide configured as a rod, which protrudes from an opening of the mould lateral region of the die, wherein preferably a longitudinal axis of the clamping slide is parallel to the first lateral direction. In addition, according to the invention, the forming device comprises an elastic element for resiliently supporting the clamping slide against a base of the opening.The arrangement of clamping slide and elastic element brings about the effect that the clamping slide can be displaceably guided in the opening of the die and can be supported by the elastic element in such a way that the blank can be resiliently clamped between the lateral punch and the clamping slide. An advantage associated therewith is that the blank clamped between clamping slide and lateral punch can be guided precisely in the first lateral direction in order to be pressed and precisely formed between the end face of the lateral punch and the mould lateral region of the die. A further advantage is that after the forming is completed and after the punches have been returned, the elastic element can expand and thus push out the clamping slide, which pushes the blank away from the forming region and allows the blank to be removed from the die.According to the invention, the forming device comprises a gripping device, by means of which the blank can be gripped at its ends, for displacing the blank along the forward direction. Advantageously, in an early phase of the forming, if there is an excess of length at the ends of the blank, the blank can thus be guided towards the die and positioned in the forming region.According to the invention, the forming device comprises two press jaws, which are displaceable relative to one another and in the second lateral direction, for pressing the blank in the second lateral direction. If the blank after the forming process has however a length or material excess at its ends, for example on the basis of a deviation of the determined or simulated from the real length change, then advantageously by means of axial pressing of the blank at its ends the material excess can be pressed into the pressing space, so that there is no length excess to be cut.According to the invention, the forming device comprises ejector pins that can be extended out of the forming region for removing a product obtained from the blank by means of forming from the die. The ejector pins advantageously make it possible to remove the blank rapidly from the forming device after the forming.In a preferred development of the invention, the 3D forming of the blank by means of the described forming device can comprise the following steps: a) forming of the blank in the first plane, and b) forming of the blank in the second plane.The forming of the blank in a forming plane (first or second plane) means that a curve shape or contour which the blank assumes in the relevant forming plane during forming lies in the forming plane and is thus a 2D curve shape or 2D contour. The forming in steps a), b) has the effect that a 3D forming is implemented by means of two 2D formings carried out sequentially or simultaneously in one forming plane each. The mentioned effect has the advantage that 2D transformations, which together reproduce the 3D transformation, and their simulations are simpler than conventional transformations and 3D simulations and the length change of the blank determined therewith and effected by the transformation is more realistic.In a preferred development of the invention, the forming of the blank in the first plane by means of a forming device with a forward punch in the separate embodiment can comprise the steps: a.1) introducing the blank into the forming region of the die, a.2) displacing the lateral punch in the first lateral direction for pressing the blank against the forming lateral region of the die, such that the blank is formed in the first lateral direction, and b.1) displacing the forward punch in the forward direction for pressing the blank against the forming base region of the die, such that the blank is formed in the forward direction.The steps mentioned have the advantageous effect that a 3D forming is thus composed of two separate 2D formings, which is simpler than a conventional 3D forming and enables a more precise simulation, whereby the determination of the length change of the blank caused by the forming is more realistic.Steps a.1)-a.3) can advantageously be carried out quickly and enable precise handling or treatment of the blank.In a preferred development of the invention, the forming of the blank with a forward punch can comprise in the unit embodiment:introducing the blank into the forming region of the die, anddisplacing the lateral punch in the first lateral direction for pressing the blank against the mold lateral region of the die and against the mold bottom region of the die.This achieves the effect of laterally delimiting the rod-shaped pressing space of the blank and advantageously enabling the lateral pressing and forming of the blank in the first and the second plane by means of a single movement (displacement in the first lateral direction) and a single forming tool (lateral punch).Preferably, when forming the blank in the first plane, the blank can assume the 2D lateral contour and in particular a 2D strip shape corresponding to the strip-shaped 2D course of the lateral punch end face and of the die-shaped lateral region. In addition, during the forming in the second plane, the blank can assume the 2D height contour, preferably during the pressing of the blank between the mold base region of the die and the end face of the forward punch.Advantageously, the respective 2D shapes can thereby be configured or fixed in the first and second plane.Preferably, the introduction of the blank into the forming region of the die can be carried out by means of the gripping device or a gravitational force. This has the advantage of uncomplicated handling and / or exact guidance and positioning of the blank at the desired location in the forming region.Preferably, after the blank is pressed between the end face of the forward punch and the pressing face of the mold base region, the blank can be pressed by means of displacement of the press jaws relative to one another in the second lateral direction, preferably until the press jaws reach the die, in particular lateral side faces of the die. This advantageously brings about the reduction or avoidance of length waste.Preferably, after step v3), the step can be carried out:v4) Hardening of the blank. The curing can be carried out by cooling the molding compound in the tempered tool or the tempered device. The shaping components of the device (die, lateral punch, and forward punch) can be flowed through by a temperature control medium (water or oil). Thus, the product obtained by means of forming can be finished advantageously.Preferably, after the blank has hardened, the punches (lateral punches, forward punches) can be moved back and the product can be moved away from the forming region of the die, either i) by means of the clamping slide, which is left free when the punches are moved back and, by means of releasing the elastic element, pushes the blank out of the forming region of the die, or ii) by means of the ejector pins, which are extended out of the forming base region in order to eject the blank out of the forming region.Preferably, the ejector pins can serve not only for ejector, but also for providing deformed rods for picking up with a gripper by defined and repeatably precise positioning in space. In order for the rods to remain on the knockouts, they can penetrate into the rods during the forming process. For this purpose, these may be conically pointed, so that they can penetrate between the fibers of the blank.The product obtained by means of forming can thus advantageously be provided, for example for storage, for transport or for installation in a motor vehicle or in a component for a motor vehicle.A forming device according to the invention is explained in more detail below with reference to drawings. They show in each case schematically: FIG. 1 shows a top view of a first embodiment of a forming device according to the invention, with a forward punch of separate design, FIG. 2 shows a side view of a first variant of the first embodiment of the forming device, FIG. 3 shows a side view of a second variant of the first embodiment of the forming device, FIG. 4 is a side view of a first variant of the second embodiment of the forming device, with a forward punch in the unit embodiment, and FIG. 5 shows a side view of a second variant of the second embodiment of the forming device, with a forward punch in the unit embodiment.Elements with the same function and mode of operation are provided with the same reference numerals in each of the FIGS. 1 to 5.In connection with the figures shown, a Cartesian coordinate system is used which is determined by three directions:x direction 20.1, x axis (first lateral direction 20.1),y-direction 20.2, y-axis, (second lateral direction 20.2),z-direction 20.3, z-axis (forward direction), in which two planes are defined:an xy plane determined by the x direction 20.1 and y direction 20.2 (first plane), anda yz plane determined by the y direction 20.2 and z direction 20.3 (second plane).FIGS. 1 and 2 show a first embodiment of a forming device 10 according to the invention, with a forward punch 12 in a separate embodiment. The forming device 10 comprises:a die 14 for receiving and forming the blank 1, having a forming region comprising a forming base region 14.2 against which the blank 1 is pressed in the z direction, and a forming lateral region 14.1 against which the blank 1 is pressed in an x direction 20.1 lateral to the z direction,a lateral punch 16, which is displaceable in the first lateral direction 20.1, for pressing the blank 1 against the mould lateral region 14.1 of the die 14, anda forward punch 12 for pressing the blank 1 against the mold base region 14.2 of the die 14, wherein the forward punch 12 is designed as an element which is displaceable in the z direction and is separate from the lateral punch 16.In addition to the variant of the first embodiment shown in FIGS. 1 and 2, a variant with a planar end face is shown in FIG. 3.In the second embodiment of the forming device 10 shown in FIG. 4 with a forward punch in a unit embodiment, this is formed as a protrusion 16.2 of the lateral punch 16 protruding in the x direction 20.1.In addition to the variant of the second embodiment shown in FIG. 4, a variant with a dip edge is shown in FIG. 5.The die 14 is formed as a rigid or immovable part of the forming device 10, whereinin the separate embodiment shown in FIGS. 1, 2, two movable parts (lateral ram 16, forward ram 12), andin the unit embodiment shown in FIG. 4, a movable part (lateral punch 16),forming the blank 1 by means of displacement relative to the die 14 and pressing against the forming region 14.1, 14.2 of the die 14.The forming region 14.1, 14.2 of the die 14 comprises an elongate pressure plate with two contact surfaces to the blank 1, each of which has a shape following the elongate shape of the blank 1, wherein the contact surfaces press the blank 1 against lateral punches 16 and / or forward punches 12.In the separate embodiment shown in FIGS. 1, 2, the forming device 10 comprises two parts or punches that are independently movable from one another, namely the lateral punch 16 that can be displaced in the first lateral direction 20.1 and the forward punch 12 that is formed separately from the lateral punch 16 and can be displaced separately.The lateral punch 16 has an end face 16.1 facing the mold lateral region 14.1 of the die 14, which end face runs in the xy-plane along the lateral contour and is strip-shaped. The mould lateral region 14.1 of the die 14 and the end face 16.1 of the lateral punch 16 are matched to one another and run complementarily to one another in order to laterally delimit the press space of the blank 1 running in the form of a strip, and thus enable the lateral pressing and forming of the blank 1 in the xy-plane.The forward punch 12 comprises a punch handle 12.2, on which the forward punch 12 can be gripped for guiding the forward punch 12 in the z-direction, and a funnel-shaped punch projection tapering conically in the z-direction, having an end face 12.1 facing the mold base region 14.2 of the die 14, which end face runs in the yz-plane along a height contour and is strip-shaped. The punch handle 12.2 represents a roof-edge-shaped widening compared to the punch projection, which widening brings about a locking on the die 14 when the forward punch 12 is displaced towards the die 14. 1. dip edge 2. plane end faceThe mold base region 14.2 of the die 14 and the end face 12.1 of the forward punch 12 are matched to one another in order to thus delimit the press space of the blank 1 running in strip form on both sides in the z direction. This enables pressing in the z direction and the forming of the blank 1 in the yz plane.In the unit embodiment shown in FIG. 4, the projection 16.2 of the lateral punch 16 has, in a region facing the mold base region 14.2 of the die 14, in the first lateral direction 20.1, a contact surface to the blank running parallel to the opposite surface of the mold base region 14.2. During the displacement of the lateral punch 16 in the x direction along the mold base region 14.2, it is ensured that the blank 1, before pressing in the first lateral direction 20.1, has cross-sectional dimensions which are smaller than the distance between the lateral punch protrusion 16.2 and the mold base region 14.2, so that the lateral punch protrusion 16.2 does not hang up on the blank 1 or become hooked therewith during the displacement.Only after the pressing space forms a closed space towards both pressing directions and the blank 1 has been pressed in the first lateral direction 20.1 so that the material of the blank 1 expands or attempts to escape against the z direction does the lateral punch protrusion 16.2 develop a pressing pressure on the blank 1 in the z direction so that the blank 1 is pressed by means of moving a single forming tool (lateral punch 16) in two directions (x direction 20.1, z direction 20.3).In the separate embodiment shown in FIG. 1, the forming device 10 comprises a clamping slide 14.3 designed as a rod, which protrudes from an opening of the forming lateral region 14.1 of the die 14, wherein a longitudinal axis of the clamping slide 14.3 is parallel to the first lateral direction 20.1. In addition, the forming device 10 comprises an elastic element 14.4 for resiliently supporting the clamping slide 14.3 against a base of the opening. As a result, the clamping slide 14.3 is displaceably guided in the opening of the die 14 and supported by the elastic element 14.4 in such a way that the blank 1 is resiliently clamped between the lateral punch 16 and the clamping slide 14.3, for guiding the blank 1 to the mould lateral region 14.1 of the die 14, against which it is laterally pressed by the lateral punch 16. In particular, by centrally clamping the blank by means of the clamping slide, displacement during the forming in the y-direction can be prevented. By means of the spring-mounted clamping slide, the clamping can be limited to an adjustable maximum dimension by a mechanical stop system.The forming device 10 further comprises a gripping device 17, which grips the blank 1 at its ends along the second lateral direction 20.2, for displacing the blank 1 along the z-direction. Thus, in an early stage of forming, when there is an excess of length at the ends of the blank 1, the blank 1 is guided toward the die 14 and positioned in the forming region.The 3D forming of the blank 1 by means of the described forming device 10 comprises the following steps: a) forming of the blank 1 in the xy-plane, and b) forming of the blank 1 in the yz-plane.The forming of the blank 1 in the xy-plane by means of a forming device 10 shown in FIGS. 1, 2 in a separate embodiment comprises the steps:a.1) Introduction of the blank 1 into the molding region of the die 14,a.2) Displacement of the lateral punch 16 in the first lateral direction 20.1 for pressing the blank 1 against the mould lateral region 14.1 of the die 14, so that the blank 1 is shaped in the first lateral direction 20.1, andb.2) Displacement of the forward punch 12 in the z-direction for pressing the blank 1 against the mould base region 14.2 of the die 14, so that the blank 1 is shaped in the z-direction.The forming of the blank 1 with a forward punch 16.2 in the unit embodiment shown in FIG. 3 comprises:introducing the blank 1 into the forming region of the die 14, anddisplacing the lateral punch 16 in the first lateral direction 20.1 for pressing the blank 1 against the mould lateral region 14.1 of the die 14 and against the mould bottom region 14.2 of the die 14.Thus, according to both embodiments, the press space of the blank 1 running in strip form is laterally delimited and enables the lateral pressing and forming of the blank 1 in the first and the yz plane.In other words, the forming method can be summarized as follows:A blank 1 already cut to final dimensions and shaped as a straight rod is heated, so that the thermoplastic matrix material is softened and formable. The flexurally soft rod 1 is placed on the die 14. The die face has a camber about the x-axis of the rod 1 to be formed.By displacing the lateral punch 16 designed as a main slide, the rod 1 is pressed against the clamping slide 14.3 displaceable in the x-direction and clamped between the main slide and the clamping slide 14.3. The clamping force is adjustable via the elastic element 14.4, which supports the clamping slide 14.3. Clamping fixes the rod 1 centrally and ensures uniform drawing-in of the rod 1 on both sides into the pressing space designed as a forming gap. The lateral contact surfaces of the main slide 16 and the die 14 with the rod 1 have the camber about the z-axis of the rod 1 to be formed. By further displacement of the main slide 16 and clamping slide 14.3, the rod 1 is deformed about the z-axis.The rod 1 is pressed either by means of the forward punch 12 which is placed from above onto the main slide 16 and the die 14. Alternatively, after depositing the rod 1 on the die 14, the forward punch 12 can first be placed on and the main and clamping slides 14.3 then displaced.A variant without a forward punch for pressing the rod 1 is shown in FIG. 3. The main slide 16 has a web 16.2 or lateral projection 16.2, which prevents the flexible rod 1 from being pushed out of the mold gap. The forming forces occurring in the z-direction are absorbed in a form-fitting manner between the main slide 16 and the die 14.In general, during the forming, the end cross section of the rod 1 changes with respect to its starting cross section. In other words, the starting cross section of the rod 1 does not have to correspond to its final cross section.List of reference characters1 Blank, rod 10 forming device 12 forward punch in separate embodiment 12.1 end face of the forward punch 12.2 punch grip 14 die 14.1 mould lateral region of the die 14.2 mould base region of the die 14.3 clamping slide 14.4 elastic element 16 lateral punch, main slide 16.1 end face of the lateral punch 16.2 projection of the lateral punch, forward punch in unit embodiment 17 gripping device 20.1 first lateral direction, x direction 20.2 second lateral direction, y direction 20.3 forward direction, z direction

Claims

Forming device (10) for a method for forming a flexurally soft, rod-shaped blank (1) made of fiber-reinforced thermoplastic, wherein the forming device (10) comprises: - a die (14) for receiving and forming the blank (1), having a forming region (14.1, 14.2) comprising a forming base region (14.2) against which the blank (1) is pressed in a forward direction (20.3) and a forming lateral region (14.1) against which the blank (1) is pressed in a first lateral direction (20.1) lateral to the forward direction (20.3), - a lateral punch (16), which is displaceable in the first lateral direction (20.1), for pressing the blank (1) against the forming lateral region (14.1) of the die (14), and - a forward punch (12, 16.2) for pressing the blank (1) against the mould base region (14.2) of the die (14), wherein the forward punch is formed i) in a separate embodiment as an element which is displaceable in the forward direction (20.3) and is separate from the lateral punch (16), or ii) in a unit embodiment as a projection (16.2) of the lateral punch (16) projecting in the first lateral direction (20.1), - a clamping slide (14.3) formed as a rod and projecting from an opening of the mould lateral region (14.1) of the die (14); - an elastic element (14.3) for resiliently supporting the clamping slide (14.3) against a base of the opening; - a gripping device (17) for gripping the blank (1) at its ends; two press jaws for pressing the blank (1) at its ends; - ejector pins which can be extended from the mold base region (14.2) of the die (14) for ejecting a product obtained from the blank (1) by means of forming, - wherein a coordinate system is determined by three directions: i) the first lateral direction (20.1), ii) a second lateral direction (20.2) which is perpendicular to the forward direction (20.3) and to the first lateral direction (20.1) and along which a lateral coordinate runs, and iii) the forward direction (20.3), - wherein a first plane is determined by the first and second lateral directions (20.1, 20.1) and a second plane is determined by the second lateral direction (20.2) and the forward direction (20.3), - the forming device (10) comprising at least one of the following features: - the lateral form region (14.1) of the die (14) extends in the first plane along a lateral contour and is preferably strip-shaped; - the lateral punch (16) has an end face (16.1) facing the lateral form region (14.1) of the die (14), which end face preferably extends in the first plane along the lateral contour and is in particular strip-shaped, wherein preferably the lateral form region (14.1) of the die (14) and the end face (16.1) of the lateral punch (16) are matched to one another; - the bottom form region (14.2) of the die (14) extends in the second plane along a height contour and is preferably strip-shaped; the forward punch (12, 16.2) has an end face (12.1) facing the mold base region (14.2) of the die (14), which preferably runs in the second plane along the height contour and is in particular strip-shaped, wherein preferably the mold base region (14.2) of the die (14) and the end face (12.1) of the forward punch (12, 16.2) are matched to one another; the projection (16.2) of the lateral punch (16) is funnel-shaped in the first lateral direction (20.1), in the unit embodiment, in a region facing the mold base region (14.2) of the die (14); the clamping slide (14.3) is displaceably guided in the opening of the die (14) and supported by the elastic element (14.4) in such a way that the blank (1) can be resiliently clamped between the lateral punch (16) and the clamping slide (14.3); the gripping device (17) is designed for gripping the blank (1) at its ends, as a result of which the blank (1) is displaceable with respect to the forming region (14.1, 14.2) of the die (14); the pressing jaws are displaceable with respect to one another along the second lateral direction (20.2) for pressing the blank (1) in the second lateral direction (20.2).Method for forming a flexurally soft, rod-shaped blank (1) made of fibre-reinforced thermoplastic by means of a forming device (10) according to claim 1, the method comprising: v1) determining a length change of the blank (1) with respect to a defined initial length, which length change is to be expected during forming of the blank (1), for reducing or avoiding length cutting, v2) cutting the blank (1) to a final length = initial length + length change, and v3) forming the blank (1) by means of the forming device (10).Method according to the preceding claim, wherein the forming of the blank (1) in step v3) comprises: a) forming the blank (1) in the first plane, and b) forming the blank (1) in the second plane.Method according to claim 3, wherein the forming of the blank (1) by means of a forming device (10) with a forward punch (12) in the separate embodiment comprises the steps: a.1) introducing the blank (1) into the forming region (14.1, 14.2) of the die (14), a.2) displacing the lateral punch (16) in the first lateral direction (20.1) for pressing the blank (1) against the forming lateral region (14.1) of the die (14), such that the blank (1) is formed in the first lateral direction (20.1), and b.1) displacing the forward punch (12) in the forward direction (20.3) for pressing the blank (1) against the forming base region (14.2) of the die (14), such that the blank (1) is formed in the forward direction (20.3).Method according to claim 3, wherein the forming of the blank (1) by means of a forming device (10) with a forward punch (16.2) in the unit embodiment comprises the steps: - introducing the blank (1) into the forming region (14.1, 14.2) of the die (14), and - displacing the lateral punch (16) in the first lateral direction (20.1) for pressing the blank (1) against the forming lateral region (14.1) of the die (14) and against the forming bottom region (14.2) of the die (14).Method according to at least one of the preceding method claims, comprising at least one of the following features: - during the forming of the blank (1) in the first plane, the blank (1) assumes the lateral contour, wherein preferably the blank (1) assumes a strip shape corresponding to the strip-shaped course of the lateral punch end face (16.1) and the die shape lateral region (14.1); - during the forming of the blank (1) in the second plane, the blank (1) assumes the height contour, preferably during the pressing of the blank (1) between the forward punch (12, 16.2) and the die base region (14.2) of the die (14); - the introduction of the blank (1) into the die region (14.1, 14.2) of the die (14) is carried out by means of the gripping device (17) or a gravitational force; shifting the lateral punch (16) in the first lateral direction (20.1) for pressing the blank (1) against the lateral form region (14.1) of the die (14), the blank (1) is clamped between the lateral punch (16) and the clamping slide (14.3) in order to guide the blank (1) such that it rests as completely as possible on the bottom form region (14.2) of the die (14) and is brought as completely as possible to the lateral form region (14.1) of the die (14) and abuts thereon; - during the displacement of the lateral punch (16) in the first lateral direction (20.1), in the unit embodiment, the projection (16.2) of the lateral punch (16) is guided over the blank (1), wherein a side surface of the projection (16.2) facing the blank (1) and formed like a funnel in the first lateral direction (20.1) exerts an increasing pressure on the blank (1) in the forward direction (20.3) with an increasing displacement of the lateral punch (16) in the first lateral direction (20.1) for pressing the blank (1) against the mould base region (14.2) of the die (14); after the forming of the blank (1) in the first lateral direction (20.1) and in the forward direction (20.3), the blank (1) is pressed by means of displacing the press jaws relative to one another in the second lateral direction (20.2), preferably until the press jaws reach the die (14), in particular lateral side surfaces of the die (14); after the step v3), the step is carried out: v4) hardening of the blank (1); after the hardening of the blank (1), lateral punches (16) and forward punches (12, 16.2) are moved back and the product is moved away from the forming region (14.1, 14.2) of the die (14), in particular ejected counter to the forward direction (20.3), preferably by means of extending the ejector pins out of the forming base region.

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