Braiding device and method for producing a fiber braid

Abstract

Method for producing a fiber braid (11) on at least one core (10), wherein the core (10) is braided with fiber material while the core (10) is passed through at least one braiding device (12), comprising the steps: - Picking up the core (10) from a core memory (13) using a feeder (14), - Feeding the core (10) to the braiding device (12) using the feeding device (14), - Capturing the core (10) on one side of the braiding device (12) opposite the feeding device (14) with a removal unit (16), characterized in that - at a braiding point where the fiber material (11) is just being deposited onto the core (10), the core is guided essentially perpendicular to its cross-section through the braiding device (12) and this alignment of the core (11) is carried out with the feeding device (14), with the removal device (16) or with both (14, 16).

Description

[0001] The present invention relates to a method for producing a fiber braid on at least one core, wherein the core is braided with fiber material while being guided through at least one braiding device essentially in a conveying direction F. Furthermore, the present invention also relates to a braiding device for carrying out this method.

[0002] From EP 1 835 060 A2, a device for braiding curved components is known. A braiding unit is movable along the axis of a mandrel. Relative movements of the braiding unit to the body being braided allow the body to be continuously covered with a braid.

[0003] From DE 38 43 488 A1, a winding system is known with a rotary drive about a rotational axis, with a machine control, with a workpiece clamping device, a thread feed device, and with an annular thread eye arranged coaxially to the rotational axis, which concentrically surrounds a workpiece and receives several winding threads from the thread feed device, which run radially and tangentially towards the workpiece and are evenly distributed around the circumference of the annular thread eye, wherein the winding of the workpiece takes place with a simultaneous translational and rotational relative movement between the annular thread eye and the workpiece, it is provided that the rotary drive rotates the annular thread eye together with the thread feed device, and that the workpiece clamping device consists of a multi-axis controlled arm.where the workpiece is clamped on one side and the arm moves the workpiece during winding along a path in the winding plane coaxially to the axis of rotation, determined by the spatial curvature of the workpiece's main axis.

[0004] An industrial robot is known from JP H07-189 096 A.

[0005] Alternatively, a method and a device are known from DE 10 2008 052 671 B3 in which individual cores are guided through braiding units, whereby they are provided with a braid. The braiding units are rotatably mounted so that they can pivot about axes that are perpendicular to the conveying direction.

[0006] However, devices known from the prior art are subject to significant limitations in core geometry, particularly regarding core curvature and cross-sectional changes. Furthermore, they are subject to stringent requirements for the inherent stability of the cores. If these cores lack sufficient stability, there is a risk of cross-sectional deformation, potentially leading to breakage. Finally, the lack of flexibility in the production process is also a disadvantage, as product changes necessitate a complete system reconfiguration. Based on this prior art, the present invention aims to provide a simplified method that overcomes these disadvantages. Furthermore, the invention aims to provide a method and a device that reduce the complexity of the system.

[0007] This problem is solved by a method and a device having the features of the independent claims. The dependent claims describe advantageous embodiments of the invention.

[0008] To solve this problem, the invention proposes a method for producing a fiber braid on at least one core, wherein the core is braided with fiber material while being guided through at least one braiding device. The method comprises at least the following steps: picking up the core from a core storage area using a feeding device, feeding the core to a braiding device using the feeding device, and capturing the core on a side of the braiding device opposite the feeding device using a removal device.

[0009] Furthermore, at a braiding point where the fiber material is just being deposited onto the core, the core can be guided through the braiding device essentially perpendicular to its cross-section. The core's orientation is achieved by the feed device, the discharge device, or both. Advantageously, this allows the use of stationary braiding devices, since the handling of the cores, i.e., their orientation relative to the braiding device, is accomplished by the feed and discharge devices.

[0010] In a further preferred embodiment of the method, several cores can be passed through the braiding device immediately one after the other, whereby joints where the ends of two adjacent cores face each other are continuously braided around, and thus no interruption of the fiber braid occurs at the joints.

[0011] Furthermore, in a further step, the fiber network can be cut at the joints between the cores using a trimming device.

[0012] Additionally or alternatively, the cores can be trimmed to a final size using the trimming device. This has the advantage that the produced preforms, i.e., the cores with the fiber braid arranged inside, are trimmed to their final dimensions.

[0013] In a preferred embodiment of the invention, the feeding device and / or the removal device can be formed from a robot with a handling system arranged thereon.

[0014] In an alternative embodiment, the feeding device can consist of a first robot and a second robot, and / or the unloading device can comprise a third and a fourth robot. This enables a particularly safe workflow in which the first robot picks up a core from a core storage unit and feeds it to the braiding point. The second robot grasps the core itself at one end facing the braiding machine, so that it is supported at two points. Through coordinated movements, the first and second robots guide the core through the braiding device, ensuring that a cross-section of the core is always guided perpendicularly through the braiding device. As soon as the core protrudes on one side of the braiding device opposite the first or second robot, the third robot grasps the core.The first robot releases the core and moves to the core storage area to pick up another core. The second and third robots then align and guide the core through the braiding unit. Once the core protrudes sufficiently, the fourth robot also picks it up. The second robot releases the core and, together with the first robot, picks up the next core, feeding it directly to the braiding point. The third and fourth robots position the core so that it can be secured with a clamping device and then trimmed to size. This creates a preform that must be overmolded or impregnated with plastic or resin to form the finished fiber semi-finished product. The fourth robot then transfers the trimmed preform to a storage area where finished preforms are kept.

[0015] In another, alternative embodiment of the method, the fourth robot transfers the braided core to another braiding device to create an additional fiber braid on top of the already produced fiber braid.

[0016] In a further aspect, the invention relates to a braiding device or braiding system comprising a braiding unit with which continuous fiber material can be braided onto a core, a feeding device for picking up and feeding the core from a core storage to the braiding unit, and a removal device for removing the braided core from the braiding unit. The core can be aligned with the braiding unit using either the feeding device or the removal device, or both, such that at a braiding point where the fiber material is just being deposited onto the core, the core can be passed through the braiding unit essentially perpendicular to its cross-section.

[0017] Furthermore, the device allows several cores to be passed through the braiding device in immediate succession, whereby a continuous fiber braid can be produced at joints where the ends of two adjacent cores face each other.

[0018] Furthermore, the device can include a trimming device for cutting the fiber braid at the joints between the cores. In another, alternative embodiment, the preform, i.e., the core with the fiber braid attached to it, can additionally or alternatively be cut to its final dimensions using the trimming device.

[0019] Furthermore, the feeding device and / or the removal device can be formed from a robot with a handling system attached to it. For the purposes of the invention, a handling system is a device with which one or more cores can be detachably attached to the robot. Such handling systems are, in particular, grippers, suction cups, electromagnetic holders, and the like. By using grippers, the handling system can adapt to different cross-sections. Thus, cores whose cross-section changes along the length of the core can be braided. When using grippers, the special feature of the handling system lies in the gripper technology, which makes it possible to grasp and convey the core, or the core braided with one or more layers of braid, at any desired point. This makes it possible to always position the core close to or near the material being handled.The grippers are positioned at the braiding point, for example, by the robots reaching over it, thus absorbing the pulling forces from the threads / fibers. This ensures that no or only minimal bending moments are transferred to the core, allowing the aforementioned flexible core materials to be used. The grippers are designed so that they neither damage the core nor the fiber structure of the braid. Advantageously, grippers with the largest possible contact area on the core are used. This distributes the gripper's force over a larger area, keeping the stress on the core to a minimum. To ensure a secure hold of the core in the gripper, the coefficient of friction between the gripper and the core, or the braid on the core, is increased. This can be achieved by using clamping grippers with jaws coated with an elastic material such as silicone or EPDM.

[0020] In a further alternative embodiment of the invention, the feeding device can comprise a first robot and a second robot, and / or the removal device can comprise a third robot and a fourth robot. A handling system is arranged on each of these robots.

[0021] In all described embodiments of the invention, depending on the operating conditions, it may be necessary for up to four robots to convey the core simultaneously. Alternatively, a single robot is also capable of absorbing the entire extraction force.

[0022] The invention is explained in more detail below with reference to the description of the figures. The claims, the figures, and the description contain a multitude of features, which are explained below in connection with exemplary embodiments of the present invention. Those skilled in the art will also consider these features individually and in other combinations in order to develop further embodiments adapted to corresponding applications of the invention.

[0023] The schematic representation shows Fig. 1. the basic structure of a wickerwork system.

[0024] The following will be based on… Fig.1. First, the structure of a braiding plant will be explained. A plurality of cores 10 are stored in a storage unit 13, for example, a magazine. The cores 10 have a curved shape in their longitudinal direction and may have a variable cross-section. To produce fiber-reinforced components, these cores 10 are first braided with a fiber material, and then the resulting braid is infiltrated with a resin or a plastic. Carbon fiber, glass fiber, aramid fiber, or combinations thereof are used as fiber materials. The cores 10 are optionally made of compacted sand, plastic, and / or metal.

[0025] The cores 10 are removed from the storage unit 13 by means of a feeding device 14 and fed to a braiding unit 12. The feeding device 14 comprises a first robot 14a and a second robot 14b. The braiding unit 12 can contain one braiding machine or multiple braiding machines connected in series. By using several braiding machines connected in series, multiple layers of fiber braid can be deposited onto the core 10 as it passes through. To better secure the cores 10 as they pass through the braiding unit 12, pressure rollers 17 are provided upstream and downstream of the braiding unit 12 in the conveying direction F. The pressure rollers 17 located downstream of the braiding unit 12 in the conveying direction F also have the effect of pressing the generated fiber braid onto the core 10.Following the braiding unit 12, a removal unit 16 is provided, comprising a third robot 16a and a fourth robot 16b. This removal unit 16 removes the cores 10 from the braiding unit 12 and places them in a further storage unit 19. The braiding system 100 has a trimming and fixing unit 15, with which the braided cores are trimmed to their final dimensions.

[0026] An online quality assurance system (18), which can be camera-based, for example, measures and checks the fiber orientations. This takes place online during production, with process data acquisition and data traceability.

[0027] The inventive method will now be explained. With the aid of the first robot 14a, a first core 10 is taken from the storage 13 and fed to a braiding point in the braiding device 12.

[0028] The second robot 14b grasps the core at the end facing the braiding device 12, so that the core is supported at two points. The braiding process begins, with the core 10 being guided through the braiding device 12. As soon as the core 10 protrudes beyond the other side of the braiding device 12, the third robot 16a grasps the core 10. Simultaneously or immediately thereafter, the first robot 14a releases the core 10 and moves to the storage unit 13 to pick up another core 10.

[0029] As soon as the first core 10 protrudes far enough, the fourth robot grasps the core so that it is supported by the third robot 16a and the fourth robot 16b. The first robot grasps another core and guides it to the braiding point immediately after the previous core. For better fixation, the cores can be connected to each other via adapters.

[0030] The third and fourth robots 16a and 16b guide the core of the braiding device 12 until it is separated by the trimming device 15 at the transition points between a first and a subsequent second core 11. The third robot 16a then releases the first core 10 and grasps the immediately following second core. The fourth robot 16b places the braided first core 10 in the storage unit 19.

[0031] The cores, which thus have a fiber braid, can be passed through the same braiding machine again or through another braiding machine to be braided with additional fiber braids. If no further braiding is desired, the braided core 10 can be trimmed to its final edge contour using the cutting device 15 to create a so-called preform 20. In a final process step, for example in an RTM tool, this is impregnated with a resin or overmolded with a plastic to produce the finished fiber-reinforced component.

[0032] The aforementioned robots 14a, 14b, 16a and 16b can be moved on linear axes, with the axes aligned parallel to the conveying direction F. This enables improved guidance and alignment of the cores 10 in the braiding device 12.

Claims

[1] Method for producing a fiber braid (11) on at least one core (10), wherein the core (10) is braided with fiber material while the core (10) is passed through at least one braiding device (12), comprising the steps: - Picking up the core (10) from a core memory (13) using a feeder (14), - Feeding the core (10) to the braiding device (12) using the feeding device (14), - Capturing the core (10) on one side of the braiding device (12) opposite the feeding device (14) with a removal unit (16), characterized by , that - at a braiding point where the fiber material (11) is just being deposited onto the core (10), the core is guided essentially perpendicular to its cross-section through the braiding device (12) and this alignment of the core (11) is carried out with the feeding device (14), with the removal device (16) or with both (14, 16). [2] Method according to claim 1, characterized by , that several cores (10) are passed through the braiding device (12) immediately one after the other, with joints where the ends of two adjacent cores (10) are opposite each other being braided around. [3] Method according to one of claims 1 or 2, characterized by , that at the joints between the cores (10) the fiber mesh (11) is cut by means of a trimming device (15). [4] Method according to any one of the preceding claims, characterized by , that the feeding device (14) and / or the removal device (16) is formed from a robot with a handling system arranged on it. [5] Method according to any one of the preceding claims, characterized by , that the feeding device (14) comprises a first robot (14a) and a second robot (14b) and / or the extraction device (16) comprises a third robot (16a) and a fourth robot (16b). [6] Braiding device (100), with - a braiding device (12) with which continuous fiber material (11) can be braided onto a core (10), - a feeding device for picking up and feeding the core (10) to the braiding device (12), - a withdrawal device for removing the braided core (10) from the braiding device (12), wherein the withdrawal device is on a side of the braiding device opposite the feed device, characterized by , that - with the feed device or the removal device or with both (14, 16) the core (11) can be aligned to the braiding device (12) in such a way that at a braiding point where the fiber material (11) is just coming to be deposited on the core (10), the core (10) can be guided through the braiding device (12) substantially perpendicular to its cross-section. [7] Device according to claim 6, characterized by , that several cores (10) can be passed through the braiding device (12) immediately one after the other, and that braiding can be done at joints where the ends of two adjacent cores (10) are opposite each other. [8] Device according to one of claims 6 or 7, characterized by a cutting device (15) for cutting the fiber braid (11) produced by braiding around the core (10) at the joints between the cores (10). [9] Device according to any one of the preceding claims 6-8 characterized by , that the feeding device (14) and / or the removal device (16) is formed from a robot with a handling system arranged on it. [10] Device according to any one of the preceding claims 6-9 characterized by , that the feeding device (14) comprises a first robot (14a) and a second robot (14b) and / or the extraction device (16) comprises a third robot (16a) and a fourth robot (16b).

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