Method for arranging at least one blade building preform element in a blade mold for frame processing, preform element, method for producing a preform element, bending tool for a blade or a yoke, and preform element processing device

Abstract

The invention relates to a method for arranging at least one blade building preform (7) in a blade mould (8) for further processing, comprising the following steps: a) placing at least one prefabricated element (7) on a mould surface of the blade mould (8), b) producing the blade mould (8) by moving at least one further prefabricated element (26) and / or at least one blade part and / or at least one production tool (10) in a movement direction along a movement path (12), the at least one further preform element (26) and / or the at least one blade part and / or the at least one manufacturing tool (10) are / is placed on the mould surface and / or the at least one preform element (7), and wherein the at least one further preform element (26) and / or the at least one blade part and / or the at least one manufacturing tool (10) is placed on the mould surface and / or the at least one preform element (7). And c) bending at least a part of the at least one bending section (9) of the at least one preform element (7) such that the at least one bending section (9) at least partially overlaps the at least one further preform element (26) and / or the at least one blade part and / or the at least one manufacturing tool (10), the at least one further pre-forming element (26) and / or the at least one blade part and / or the at least one manufacturing tool (10) are moved along the movement path (12) such that the at least one bending section (9) blocks a reverse movement of the at least one further pre-forming element (26) and / or the at least one blade part and / or the at least one manufacturing tool (10) in the opposite direction along the movement path (12).

Description

TECHNICAL FIELD

[0001] The present invention relates to a method for arranging at least one blade construction preform element in a blade mold for further processing. Furthermore, the present invention relates to a preform element to be used in the method. In addition, the present invention relates to a method for manufacturing the preform element. Furthermore, the present invention also relates to a bending tool for a blade mold or yoke and a preform element handling device. BACKGROUND

[0002] Wind turbines generally comprise a rotor with a plurality of rotor blades, usually for converting wind energy into electrical energy by means of a generator. Due to the enormous size of wind turbine blades, their manufacture is a major challenge for the manufacturers of wind turbines.

[0003] One technique to facilitate the manufacture of wind turbine blades is the respective use of preform construction elements or preform elements. Preform elements are pre-fabricated parts or segments of a blade for constructing the final blade. In many cases, preform elements are manufactured by stacking plies of a specific fiber material with a binder applied to each ply. Next, the binder is activated, for example by heating the plies. This activation causes the plies to bind together so that the preform element can be handled as a single component. The blade is then manufactured in a blade mold by placing the preform element and, in particular, further blade components on the blade mold surface and adhering these components to each other, in particular using epoxy resin.

[0004] In particular, problems can arise, especially for monolithic blades, since the preforms are usually placed on the mold surface with some overlap to ensure the structural integrity of the blade. A monolithic blade is a single-piece wind turbine blade manufactured in a single process. After the preform elements and, in particular, further blade components are arranged in the blade mold, these components of the monolithic blade are adhered to each other, in particular by injecting resin under vacuum. Subsequently, the resin is hardened at high temperature. Finally, the blade is removed from the blade mold. This technique allows the blade to be manufactured as a complete, seamless component, which is completed in a single process.

[0005] As already mentioned, the preform elements and / or other components and / or manufacturing tools of the blade required for the respective manufacturing process usually overlap each other. Since these components can be assumed to be rigid bodies, problems can arise in placing these components on the mold surface and / or bringing them successively into their designated position, since already positioned preform elements can hinder the respective required movement of further preform elements and / or blade components and / or manufacturing tools. SUMMARY

[0006] It is an object of the present application to realize a reinforcement concept for manufacturing a wind turbine rotor blade, in particular in order to overcome the above-mentioned problems.

[0007] According to the present application, the problem is solved by a method as described in the opening paragraph, comprising the following steps: a) placing the at least one preform element on a mold surface of a blade mold, b) placing at least one further preform element and / or at least one blade component and / or at least one manufacturing tool on the mold surface and / or the at least one preform element by moving it in a movement direction along a movement path, and c) bending at least a portion of at least one bending section of the at least one preform element such that the at least one bending section at least partially overlaps the at least one further preform element and / or at least one blade component and / or at least one manufacturing tool, such that the at least one bending section blocks a reverse movement of the at least one further preform element and / or at least one blade component and / or at least one manufacturing tool in an opposite direction along the movement path.

[0008] In the method according to the present application, in step a) the preform element is brought into its designated position on or in the blade mold. Thereafter, during step b) the further preform element and / or blade component and / or manufacturing tool is also brought into its designated position on or in the blade mold or on the preform element. The designated positions are the positions of the respective components relative to the mold surface and relative to each other which are required for further processing, in particular for adhering the respective components to each other. In particular, the relative positions between the components in their designated positions on or in the blade mold correspond to the relative positions between these components in the final blade.

[0009] With regard to step a), a blade mold having a mold surface is provided. The blade mold is adapted to hold or carry the preform element and the further preform element and / or blade component and / or manufacturing tool in their designated positions. With regard to placing the at least one preform element on the mold surface, in particular several preform elements can be placed on the mold surface adjacent to each other and / or stacked. The preform elements can be placed directly on the mold surface. However, it is also possible that further components of the preform elements can be arranged on the mold surface before the preform elements are placed there.

[0010] With regard to step b), the further preform element and / or the blade component and / or the manufacturing tool is brought into its assigned position. In particular, if the further preform element is provided, it can also be arranged on the mold surface, in particular adjacent to the preform element. If the blade component and / or the manufacturing tool is provided, it can be positioned on the preform element and in particular on the further preform element. Thus, the position of the blade component and / or the manufacturing tool can be within or inside the blade, in particular in order to achieve sufficient mechanical stability of the blade. The further preform element and / or the blade component and / or the manufacturing tool can be placed directly on the mold surface and / or on the preform element. However, it is also possible that further components of the preform element are arranged on the mold surface and / or on the preform element before the further preform element is placed there.

[0011] By moving the further preform element and / or the blade component and / or the manufacturing tool in a movement direction defined by a movement path, in particular a one-dimensional movement path, the further preform element and / or the blade component and / or the manufacturing tool is placed in its assigned position. The movement path can be straight or curved. Typically, the movement path leads vertically downwards to the mold surface, so that the further preform element and / or the blade component and / or the manufacturing tool is lowered from above on the mold surface or the preform element.

[0012] With regard to step c), the curved section of the preform element is bent, so that it overlaps the further preform element and / or the blade component and / or the manufacturing tool. This overlap results in the effect that the curved section blocks the reverse movement of the further preform element and / or the blade component and / or the manufacturing tool in the opposite direction along the movement path. Thus, after completion of step c), the components of the blade to be manufactured comprise a shape and are in a relative position to each other, so that due to the overlap it is not possible to remove the further preform element and / or the blade component and / or the manufacturing tool along the movement path. The respective configuration results in a stable mechanical stability of the blade to be manufactured, in particular of the integral blade.

[0013] Since the further preform element and / or the blade part and / or the manufacturing tool is brought into its designated position before the preform element is brought into its designated position, the respective overlap will block the positioning of the further preform element and / or the blade part and / or the manufacturing tool into the designated position. This means that it will not be possible to move the preform element and / or the blade part and / or the manufacturing tool along the movement path to the designated position, because the curved section will be arranged such that the further preform element and / or the blade part and / or the manufacturing tool will hit the curved section during this movement due to its physical expansion. In order to avoid this problem, one basic idea of the present invention is that the preform element or the curved section respectively comprises a temporary shape such that it does not block the movement path of the further preform element and / or the blade part and / or the manufacturing tool when it is brought into its designated position in step b). Once the part of the blade is brought into its designated position, the temporary shape is curved or deformed into the final shape in step c) such that the preform element overlaps with the further preform element and / or the blade part and / or the manufacturing tool.

[0014] The curved section of the preform element can be a part of the preform element, but also the entire preform element. The curved section can be curved to bring the preform element into the final shape without damaging the respective preform element. Thus, the preform element is formed into the final shape by elastic and / or plastic bending.

[0015] The mold surface can be a surface which is particularly concave or convex, which comprises an overall shape corresponding to the shape of the final blade. The shape of the mold surface preferably also corresponds to the shape of the respective part located there. The mold surface typically comprises a U-shape with an upwardly facing opening. The blade mold can be made of a material like wood or plastic, in particular foam plastic. The blade mold can be made of a material like metal such that the blade mold can withstand higher temperatures which can be required for further manufacturing processes, in particular hardening of the resin. The blade mold can be made of a composite material, for example a fiber composite material.

[0016] The preform element can be manufactured such that it initially or inherently comprises the temporary shape. In this embodiment, the manufacturing of the preform element already realizes the temporary shape required for performing step b) of the method according to the present invention.

[0017] Alternatively, the preform element can be manufactured such that it initially or inherently comprises the final shape. In particular, in this embodiment, the at least one curved section of the at least one preform element placed on the mold surface will block the movement path of the at least one further preform element and / or the at least one blade component and / or the at least one manufacturing tool in step a), wherein between step a) and step b) the at least one curved section is bent or deformed such that it does not block the movement path. Accordingly, between placing the preform element on the mold surface and placing the further preform element and / or blade component and / or manufacturing tool at its designated position a respective step is required, because otherwise it would not be possible to move the further preform element and / or blade component and / or manufacturing tool along the movement path to its designated position. Accordingly, in this embodiment, two bending processes of the respective curved section are performed, namely between step a) and step b) and in step c).

[0018] The curved section can be elastic such that in order to change it from the final shape to the temporary shape between step a) and step b) the elastic counterforce has to be overcome. Then, in step b) the curved section has to be actively held to the temporary position, i.e. the respective bending force has to be maintained while the further preform element and / or blade component and / or manufacturing tool is brought to its designated position. The bending of the curved section in step c) can be performed by canceling the bending force. Then, the curved section elastically changes to the final shape.

[0019] The curved section can be plastically deformed such that in order to change it from the final shape to the temporary shape between step a) and step b) the plastic counterforce of the component has to be overcome. Accordingly, in step b) the curved section does not need to be actively held to the temporary position, because the performed bending leads to a stable temporary shape. In step c) the bending of the curved section can be performed by applying another bending force on the curved section, which bending force is directed in the opposite direction compared to the bending force required to change the curved section to the temporary shape. This bending leads to a stable final shape of the curved section.

[0020] The bending of the curved section can also be a combination of plastic bending and elastic bending. In other words, once the curved section is changed from the final shape to the temporary shape or vice versa and released, it will automatically leave its current shape, but not completely return to the respective other or previous shape, i.e. to the final shape or the temporary shape. For this, a separate bending process is required.

[0021] In one possible embodiment of the method according to the application, the at least one preform element placed on the mold surface in step a) is configured as an overall profile of an upwardly open U shape, which U shape comprises an outer end as a curved section and protruding above the blade mold. The U shape can be realized by one preform element having the corresponding profile. In this embodiment, at least one of the lateral end sections of the U-shaped preform element does not come into contact with the mold surface, but protrudes upward into the area above the blade mold. This section realizes the curved section. Alternatively, the U shape can also be realized by several preform elements positioned next to each other on the mold surface. The profiles of these preform elements realize the overall U shape. At least one of the lateral end sections of the lateral outer preform elements does not come into contact with the mold surface, but protrudes upward into the area above the blade mold. This section realizes the curved section.

[0022] The at least one manufacturing tool can be a mandrel. The mandrel generally provides sufficient mechanical stability for the blade or the corresponding arrangement to be produced, wherein the preform elements can constitute the outer skin of the blade. In particular a frame-like mandrel can extend over the entire profile of the interior of the blade. Several mandrels can be arranged along the longitudinal extension of the blade. The mandrel can comprise an elongated structure, so that it extends over at least a portion of the longitudinal extension of the blade. After the manufacturing process of the blade has been completed, the mandrel can be removed from the blade, for example by moving the mandrel, in particular after disassembly, in the longitudinal direction of the blade and removing it via the blade root opening.

[0023] In step b), the mandrel can be placed from above on the at least one preform element via a movement path leading through the open end of the U shape. In this embodiment, a crane can be used to lower the mandrel onto the blade mold and the preform elements. A yoke suspended on a rope of the crane can be provided, wherein the mandrel is held by the yoke. The movement path leads vertically downward to the open U shape, while the vertical legs of the U shape have sufficient distance from each other for the interim shape, so that the mandrel fits between the legs when it is brought into its designated position.

[0024] After the mandrel has been brought into its designated position, at least one of the outer ends of the U shape, i.e. the at least one curved section, is bent, so that the outer ends face each other and block the movement path. In this state, i.e. in the state of the final shape, the mandrel is at least partially surrounded by the preform elements, wherein the U shape can constitute a C shape.

[0025] According to a possible embodiment of the method according to the application, in step a) at least one of the at least one outer end of the U-shape is bent such that it faces the other outer end, so that the movement path is blocked, wherein between step a) and step b) at least one of the outer ends is bent away from the other outer end, so that said outer end does not block the movement path. In this embodiment, the at least one preform element can be manufactured such that it initially or inherently comprises the final shape, for example a final C-shape. Between step a) and step b) the bent section is bent from the final shape into a temporary shape. During this time, the overall profile, in particular from the C-shape, is changed into a U-shape with a sufficient distance between the vertical bars, so that the mandrel can be brought into its designated position.

[0026] After the mandrel has been brought into its designated position and step c) has been completed, an exposed portion on the upper section of the mandrel can remain, which is in particular located between the outer ends of the U-shape or in particular of the C-shape. In order to cover this portion, at least one upper preform element can be positioned on the exposed portion after step c). The preform element and the upper preform element can achieve an overall profile with a closed O-shape, which encloses the mandrel.

[0027] According to a possible embodiment of the method according to the application, in step b) the at least one further preform element is placed on the mold surface laterally relative to the at least one preform element, wherein the at least one bent section is at least one lateral section of the at least one preform element, wherein in step c) the at least one portion of the at least one bent section is bent such that it overlaps at least one lateral section of the at least one further preform element. In this embodiment, at least one portion of the bent section in the temporary shape can be bent upwards away from the mold surface, so that it does not block the movement path leading to the mold surface from above. Thus, the bent section or the respective portion thereof constitutes or comprises a shutter which is closed to achieve the overlap in step c).

[0028] The lateral section of the preform element and the lateral section of the further preform element can correspond to each other in terms of their shape. Said lateral sections can be laterally protruding and in particular tapering portions of the respective preform element. Thus, the lateral section of the preform element forms a joint between two adjacent preform elements, which can provide a resin closure in the further manufacture of the blade.

[0029] With regard to the final shape, the lateral section or the curved section of the preform element can accordingly comprise an upper protrusion and a lower protrusion with a space therebetween. Thus, the lateral section of the preform element can have the shape of a crocodile mouth. The protrusion of the lateral section of the further preform element can be arranged in the space between the upper protrusion and the lower protrusion. In this embodiment, the lateral section of the further preform element is sandwiched between the protrusions of the lateral section of the preform element. The protrusions can be tapered. While the lower protrusion can be in direct contact with the mold surface, the upper protrusion can implement the shutter closed in step c).

[0030] In a possible embodiment of the method according to the application, at least a portion of the at least one curved section is elongated parallel to the plane of the mold surface in step a), wherein between step a) and step b) the at least a portion of the at least one curved section is curved upward away from the mold surface such that it does not obstruct the movement path leading to the mold surface from above. In this embodiment, the at least one preform element can be manufactured such that it inherently comprises the final shape, e.g. the shape required for the overlap with the lateral section of the further preform element. Between step a) and step b), the curved section is curved from the final shape into a temporary shape. In this state, the lateral section of the further preform element passes the curved section while the further preform element is brought into its designated position.

[0031] Preferably, at least one of the at least one curved section comprises a reduced stiffness, in particular a reduced coefficient of elasticity, compared to the rest of the respective preform element. In this embodiment, in particular only the curved section is bendable, while the rest of the respective preform element can be rigid. The reduced stiffness makes the curved section bendable such that changing it from the temporary shape into the final shape (and in particular vice versa) does not cause damage to the structure of the respective preform element.

[0032] The at least one preform element can comprise at least one protruding and flexible, in particular string-like, tape-like or mat-like, pulling device, wherein the bending of the at least one curved section is performed by pulling the at least one pulling device against the counterforce, in particular the elastic counterforce, of the respective preform element and attaching the free end of the at least one pulling device to a stationary part, in particular to the upper lateral flange of the blade mold. The pulling device can be an integral part of the preform element. Thus, a portion of the pulling device can be arranged in the interior of the preform element, in particular between two layers of the stack constituting the preform element. The pulling device can be attached on the surface of the preform element, in particular by an adhesive.

[0033] In particular, if the pulling device is rope-like or band-like, several pulling devices can be arranged along the longitudinal extension of the preform element. In particular, if the pulling device is mat-like, it can extend over at least a portion of the longitudinal extension of the preform element.

[0034] The pulling device can be attached on the stationary part by means of an attachment tool, in particular a clamping tool. The attachment tool can be movably or slidably attached to the stationary part, in particular to the upper transverse flange of the blade mold, so that the extension of the bend can be adjusted by bringing the attachment tool into the desired position.

[0035] After step c), the at least one preform element and the at least one further preform element and / or the at least one blade part can be adhered to each other, in particular by injecting resin into and / or onto the parts. In this step, the final mechanical structure of the blade is achieved, in particular so that no mandrel is required anymore. The resin achieves a mechanically stable connection between the respective parts of the blade, and in particular in case the resin penetrates the parts, a further stiffening of the parts is achieved. If the manufacturing tool provided as a mandrel, the parts are not adhered to the (further) preform element, since the mandrel is removed after the cured resin.

[0036] The parts that achieve the final blade can be arranged in a mold cavity, which can be achieved by a mold surface and optionally by a further mold surface of a further blade mold arranged on the blade mold. In the cavity, a vacuum can be drawn, and resin, for example, epoxy resin, can be injected into the cavity. Subsequently, the resin can be hardened at a respective high temperature. Finally, after the resin has hardened, the blade is removed from the blade mold.

[0037] Furthermore, the present application also relates to a preform element to be used in a method as described in the foregoing description. All advantages, aspects and features explained for the method according to the present application can be transferred to the preform element according to the present application and vice versa.

[0038] The preform element according to the present application comprises at least one curved section, in particular a transverse curved section, which has a reduced stiffness compared to the rest of the preform element. The preform element comprises a laminate structure with several layered preform parts, wherein an activated adhesive adheres adjacent preform parts to each other. In the at least one curved section, the adhesion between at least two adjacent preform parts is reduced compared to the rest of the preform element, or is not formed. The reduced or not formed adhesion leads to a reduced stiffness of the curved section.

[0039] The preform parts can initially be flexible layers, for example consisting of or comprising fiber mats or fiber sheets, which can be made rigid by activating the adhesive. The preform parts can comprise a fabric with glass fibers, carbon fibers and / or aramid fibers, which can be impregnated with an adhesive. The preform parts can be rigid or rigid core materials, in particular consisting of balsa wood or plastic material.

[0040] Furthermore, the present application also relates to a method for manufacturing a preform element as described in the preceding section. All advantages, aspects and features of the method according to the present application for arranging at least one blade building preform element in a blade mold for further processing and / or of the preform element according to the present application can be transferred to the method for manufacturing a preform element and vice versa.

[0041] The method according to the present application for manufacturing a preform element is characterized in that several, in particular mat-like and / or rigid, preform parts are arranged on the shaped preform mold surface of a preform mold to constitute a stack, wherein the adhesive of at least one of the preform parts is activated to adhere the adjacent preform parts to each other.

[0042] The preform parts can be placed on the preform mold surface of the preform mold as a lower preform mold. The preform mold surface of the upper preform mold can be positioned on the resulting stack. The preform mold surface defines the shape of the stack and thus of the preform element to be manufactured. The stack can be arranged in at least one sealed vacuum bag, wherein a vacuum can be established in the vacuum bag such that the shape of the stack adapts to the shape of the preform mold surface. Once the stack is in its specified shape, the adhesive can be activated.

[0043] The adhesive can be a powder adhesive, which can be activated by applying heat, for example. The solid particles of the powder adhesive are liquefied or at least softened by the thermal energy and coat the respective preform parts. The cooling of the adhesive subsequently causes the preform parts to adhere to each other and / or to become rigid.

[0044] In one possible embodiment of the method according to the present application, in particular transverse curved sections of the stack, a separating part is arranged between at least two adjacent preform parts to prevent or impede the adhesive from adhering the preform parts to each other during the activation of the adhesive. In particular, the separating part, which is impermeable or perforated, serves to prevent the adhesive from coming into contact with the two adjacent preform parts and thus to prevent them from adhering to each other. Alternatively, the separating part can impede the adhesive from coming into contact with the two adjacent preform parts. Thus, the adhesive effect of connecting the preform parts to each other by the adhesive is weakened. After the activation of the adhesive, the separating part can be removed from the preform element.

[0045] The separating component can be a polymer foil, in particular a perforated polymer foil, wherein the polymer foil is removed from the preform element after the adhesive is activated, in particular by pulling the protruding section of the polymer foil away from the preform component. As the polymer foil is arranged in the stack between two preform components, this protruding section can protrude laterally from the resulting preform element. Thus, by pulling on the protruding section of the polymer foil, it can be removed from the preform component. To facilitate the removal of the separating component, several layers of the polymer foil, in particular folded, can be arranged between two adjacent preform components. Exemplarily, one or in particular two or more stacked polymer foils can be folded such that both open ends of the polymer foil protrude from the resulting preform element.

[0046] In the curved section of the stack, the amount of adhesive can be reduced compared to the rest of the preform element. Having less adhesive in this area leads to the effect that the adhesion of the adhesive holding the preform components together is not as great as in the rest of the preform element.

[0047] In the curved section of the stack, less heat can be applied during the activation of the heat-activatable adhesive compared to the rest of the preform element. In this embodiment, the heat in the joint section is reduced compared to the rest of the preform element. Thus, the adhesive is not fully activated in the curved section and thus only partially activated. In particular, if the adhesive is a powder adhesive, only a part of the adhesive is able to liquefy, while the other part remains in its powder structure, so that the adhesion is also reduced in this area. For this purpose, a heating device, in particular an oven, can be used for generating different heating temperatures in different areas. Additionally or alternatively, a thermal isolation device like a heat shield can be positioned over the curved section so that the heat reaching the interior of the curved section is reduced during the activation process.

[0048] In the curved section of the stack, a mechanical load can be applied to reduce the adhesion of the adhesive after the adhesive is activated. In this embodiment, an external force is applied to the curved section after the adhesive is activated so that the activated adhesive at least partially disintegrates, which leads to a reduced adhesion between the respective preform components. This mechanical load can have mode I, II, or III or a combination of these modes. For mode I, the external force acts in vertical direction with respect to the height of the stack. For modes II and III, the external forces act in the plane of the layers of the stack. In mode II, these forces point laterally outward, and in mode III, these forces point in the longitudinal direction of the respective preform element.

[0049] Furthermore, the present application also relates to a bending tool for a blade mold or yoke, comprising a stationary part and a bending part. The stationary part is connectable or attached to the blade mold or yoke, in particular by means of a screw connection or a clamping connection. The bending part is movably connected or attached to the stationary part, such that for a state of the bending tool and at least one preform element held by the blade mold or yoke, during a movement of the bending part, an interaction between the bending part and a bending section of the at least one preform element results in a bending of the at least one preform element. The bending part and the stationary part can be connected by means of guiding means, in particular guiding tracks, such that the bending part is linearly movable relative to the stationary part. Fixing means, such as clamping means, can be provided to fix a current position of the bending part relative to the stationary part. All advantages, aspects and features of the method for arranging at least one blade building preform element in a blade mold for further processing according to the present application and / or the preform element according to the present application and / or the method for manufacturing a preform element according to the present application can be transferred to the bending tool according to the present application and vice versa.

[0050] The bending tool can be used in accordance with the above described method for arranging the at least one blade building preform element in a blade mold for further processing. Moving the bending part relative to the stationary part attached to the blade mold or yoke can result in that at least a portion of the bending part interacts, in particular contacts, the bending section such that the movement of the bending part causes the bending section to change from a temporary shape to a final shape or vice versa.

[0051] In one possible embodiment of the bending tool according to the present application, the bending part comprises a profile having at least two bars being angled relative to each other. The angle between the bars can be between 45° and 135°. One of the bars is movably mounted on the stationary part along its longitudinal direction, wherein for a state of the bending tool held by the blade mold or yoke, the other bar is adapted to grab the bending section during its movement. In particular, the bending part can comprise an L-shaped profile having two bars having an angle therebetween of preferably 90°. In particular, one of the bars, for example the horizontal bar of the L-shape, is attached to the stationary part and can be guided in horizontal direction. The other bar, for example the vertical bar of the L-shape, can protrude downwards such that the bending part engages into the profile made of the preform element.

[0052] This embodiment of the bending tool can be used in particular in the method as described above, wherein the at least one preform element placed on the surface of the mold is configured with an overall profile of an upwardly open U-shape. In particular, in this case, a stationary component with an adjustable height can be attached to the upper transverse flange of the blade mold. The height of the stationary component can be adjusted so that the horizontal bar is located above one of the bending sections. The vertical bar protrudes downward into the open end of the U-shape. Moving the bending component laterally outward relative to the longitudinal direction of the blade mold or the preform element brings the vertical bar into contact with the bending section to increase the distance of the bars of the U-shape in order to release the movement path. The bending component can be fixed in the respective end position by means of a fixation device so that the elastic counterforce of the preform element is compensated and the movement path remains clear. The fixation device can be opened as soon as the blade component and / or the manufacturing tool is brought into its designated position, which allows the bending section to return to its final shape.

[0053] Next, a possible embodiment of the bending tool will be described, which is to be used in particular in the method as described above, in which a pulling device is provided. The bending component can implement an attachment device for attaching the free end of the pulling device. Moving the bending component causes a pulling of the pulling device, in particular against the elastic counterforce of the preform element, and thus, a bending of the bending section. The bending device can be used to attach the free end of the pulling device to a fixation device as stationary component. Preferably, the bending component can be guided along a rail-like guide on the fixation component to allow different bending amplitudes of the bending section.

[0054] Furthermore, the present invention also relates to a preform element handling device comprising at least one bending tool according to the foregoing description. All advantages, aspects and features of the method according to the present invention for arranging at least one blade building preform element in a blade mold for further processing and / or the preform element according to the present invention and / or the method for manufacturing a preform element according to the present invention and / or the bending tool according to the present invention can be transferred to the preform element handling device according to the present invention and vice versa.

[0055] The handling device can be a yoke for lifting the preform element. The yoke is a device, in particular a frame-like device, for lifting the preform element. The yoke can comprise a preform element attachment device which allows the preform element to be attached to the yoke or held by the yoke. The yoke can comprise a crane connection device which allows the yoke to be connected with the ropes of a crane and lifted by the ropes of the crane.

[0056] The handling device can be a blade mold with a bending tool attached in particular to the upper transverse flange. BRIEF DESCRIPTION OF DRAWINGS

[0057] Other objects and features of the present application will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the application. The drawings, schematically show: Figure 1 is a view of a wind turbine comprising several blades, while for manufacturing a blade, a blade building preform element is arranged in a blade mould in order to be further processed by a method according to a first embodiment of the present application, Figure 2 - 6 is Figure 1 is a cut view of one of the blades 5 of the wind turbine 1 during the manufacturing process thereof, wherein the cut line is indicated in Figure 1 VI - VI, Figures 7-8 is Figures 2-6 is a detailed view of the curved section of the preform element shown in Figure 9 is a cut view of a preform element according to an embodiment of the present application, in particular to be used for a method as by means of Figures 2-6 described, wherein a method according to an embodiment of the present application for manufacturing the preform element is described, Figure 10 is Figure 9 a detailed cut view of the preform element 7 during the manufacturing process thereof, and Figures 11-13 is a detail regarding a second embodiment of the method according to the present application for arranging a preform element in a blade mould in order to be further processed. DETAILED DESCRIPTION

[0058] Figure 1 A wind turbine 1 is shown, which comprises a tower 2 on which a nacelle 3 is arranged. On the front of the nacelle 3, a hub 4 is provided having several, in particular three, blades 5. The hub 4 is mounted so that it can rotate about a horizontal rotation axis. The wind driven rotation of the hub 4 is transmitted to a generator 6 located in the nacelle 3. The power output of the generator 6 can be in the range of several megawatts, in particular between 1 and 40 megawatts.

[0059] Figures 2 to 6 Steps of a method according to a first embodiment of the present application for arranging a preform element 7 in a blade mould 8 in order to be further processed, i.e. for manufacturing a blade 5, are shown. Figures 2 to 6 A cut view of a blade 5 to be manufactured is shown, wherein Figure 1 the cut line indicated by VI - VI in correspondingly is perpendicular to the longitudinal direction of the blade 5, the preform element 7 and the blade mould 8.

[0060] The blade mold 8 is open with respect to the vertical direction, wherein the mold surface of the blade mold 8 is curved downward and thus concave. With regard to Figure 2 In a first step, three preform elements 7 are exemplarily placed next to each other on the mold surface, such that the overall profile of the preform elements 3 comprises a U shape which is open upward. The two lateral preform elements 7 each comprise a curved section 9 which protrudes above the blade mold 8. The curved sections 9, i.e. the outer ends of the U shape, are curved such that these outer ends face each other. More precisely, in Figure 2 the state shown in

[0061] Next, with regard to Figure 3 the curved sections 9 are curved outward, or in other words, away from each other, such that the curved sections 9 comprise a temporary shape. This curvature is performed against the elastic counterforce of the preform elements 7 or the respective curved sections 9.

[0062] Next, with regard to Figure 4 the manufacturing tool 10, which is the mandrel 11, is placed on the preform elements 7 from above via a movement path 12 which leads through the open ends of the U shape. As can be seen from Figures 2 to 4 the curved sections 9 are curved, because otherwise the curved sections 9 would block the movement path 12 of the manufacturing tool 10, since the manufacturing tool 10 would hit the curved sections 9 such that it would not be possible to bring the manufacturing tool 10 into its designated position. With respect to the longitudinal direction of the blade 5, several manufacturing tools 10 or mandrels 11 are respectively placed in the interior of the blade 5. The mandrel 11 provides sufficient mechanical stability for the blade 5 to be produced or for the respective arrangement of the manufacturing process. After the completion of the blade 5, the mandrel 11 is removed from the blade 5, for example by moving the mandrel 11, in particular the disassembled mandrel 11, along the longitudinal direction of the blade 5 and by removing it through the opening of the blade 5 at its blade root.

[0063] In addition to the manufacturing tool 10 or as an alternative to the manufacturing tool 10, a blade part which has a similar structure to the mandrel 11 and which remains in the final blade can be positioned as described in the preceding paragraphs.

[0064] Figure 5 A state is shown in which the manufacturing tool 10 is located in its designated position. In the state shown in Figure 5 the curved sections 9 have been curved from the temporary shape into a final shape. Exemplarily, this final shape is the same shape as shown in Figure 2 As can be seen from Figure 5 the curved sections 9 in the final shape partially overlap with the manufacturing tool 10, such that the curved sections 9 block the counter movement of the manufacturing tool 10 in the opposite direction along the movement path 12.

[0065] Next, with regard toFigure 6 The upper preform 13 is placed on the manufacturing tool 10 such that the preform 7 and the upper preform 13 form an integral cross-section of a closed O-shape surrounding the manufacturing tool 10. Therefore, the preform 7 and the upper preform 13 constitute the outer skin of the blade 5, wherein the mandrel 11 is located inside the blade 5 and ensures sufficient mechanical stability of the blade 5 during its manufacturing process.

[0066] about Figures 2 to 6 In the embodiments of the method of the present invention shown, the prefabricated element 7 or the curved segment 9 accordingly already has a final shape, either initially or inherently, wherein, Figure 3 The bending or deformation shown causes the bent segment 9 to take on a temporary shape, which allows the manufacturing tool 10 to be placed in its designated position. Thereafter, as... Figure 5 As shown, the curved segment 9 bends back from the temporary shape to the final shape. Alternatively, the prefabricated element 7 may initially have a temporary shape, so that it is not necessary to... Figure 3 The bending only requires bending the bending segment 9 from the temporary shape. Figure 5 The final shape shown.

[0067] After the component of blade 5 is brought into its designated position, such as Figure 6 As shown, prefabricated element 7 and upper prefabricated element 13 are adhered to each other, particularly by injecting resin into or onto these components. For this purpose, exemplarily, an upper blade mold having an upper mold surface (not shown) is arranged on a blade mold 8 to create a cavity in which the prefabricated components 7 and 13 are arranged. Liquid epoxy resin is introduced into this cavity under vacuum conditions and subsequently hardens. In the next step, the mandrel 11 is removed from the completed blade 5.

[0068] Next, we will describe about such Figure 3 Details of the steps for bending the bent segment 9 are shown below. Figure 7 A first alternative for performing this bending process is shown, and Figure 8 A second alternative for performing this bending process is shown.

[0069] refer to Figure 7Fig. 1 shows a bending tool 14 according to an embodiment of the present application. The bending tool 14 is a component of a blade mold 8 which is a precast element handling device according to an embodiment of the present application. However, the bending tool 14 can be a separate component with respect to the blade mold 8 attached thereon. According to another alternative, the bending tool 14 can be part of a yoke which is a precast element handling device according to another embodiment of the present application. The bending tool 14 can be a separate component with respect to the yoke attached thereon. The yoke is a particularly frame-like device for lifting a precast element. The yoke can comprise precast element attachment means which allow the precast element to be attached to or held by the yoke. The yoke can comprise crane connection means which allow the yoke to be connected with the ropes of a crane and to be lifted by the ropes of a crane.

[0070] The bending tool 14 comprises a stationary component 15 and a bending component 16. The stationary component 15 is attached to an upper transverse flange 17 of the blade mold 8 by means of e.g. screwing means, such that the stationary component 15 realizes a stationary component. The stationary component 15 is preferably height-adjustable with respect thereto. The bending component 16 is movably mounted to the stationary component 15 by means of e.g. a rail-like guiding means which is not explicitly shown in the figure. This allows the bending component 16 to be moved with respect to the stationary component 15 in a transverse direction with respect to the longitudinal direction of the blade mold 8. The bending component 16 comprises an L-shaped cross section with a horizontal bar 18 and a vertical bar 19, wherein the horizontal bar 18 is movably mounted on the stationary component 15 and the vertical bar 19 projects downwards, such that upon transversely outward movement of the bending component 16, the vertical bar 19 interacts with the precast element 7, wherein the direction is indicated by the arrow in Figure 7 .

[0071] In Figure 7 , the final shape is indicated by the dashed line and the temporary shape is indicated by the solid line. Once the bending section 9 is in its temporary shape, the position of the bending component 16 with respect to the stationary component 15 is fixed by fixing means, particularly clamping means, which are not shown in the figure. Figure 7 The bending process shown in Figure 5 is performed against the elastic counterforce of the bending section 9. Once the manufacturing tool 10 is brought into its designated position (see , the fixing means are opened or released, such that the bending section 9 elastically returns to its final shape which overlaps with the manufacturing tool 10. However, it is also possible that the bending section 9 does not completely elastically move back to the final shape. In this case, another bending step is performed for bringing the bending section 9 into the final shape.

[0072] In the longitudinal direction of the blade mould 8, several bending tools 14 can be arranged. Alternatively, one bending tool 14 can be provided which extends over a majority or the entire portion in the longitudinal direction of the blade mould 8, wherein the bending component 16 can be an angular track with a corresponding longitudinal elongation, in particular with an L-shaped cross section. Preferably, several bending tools 14 are present on the left and right side of the blade mould 8, in particular on the opposite lateral flanges 17.

[0073] Figure 8 A second alternative to the bending process shown in Figure 3 is shown. Figure 8 The preform element 7 comprises a stack-like structure with several layers. Exemplarily, two stacks 23 of fibre sheets are provided and a rigid or stiff core component 24 made of balsa wood is sandwiched between the stacks 23. In contrast to the stacks 23, the core component 24 does not extend over the blade mould 8, such that the required flexibility for bending the bending section 9 is ensured.

[0074] The preform element 7 comprises protruding and flexible, in particular string-like, tape-like or mat-like, pulling means 20, wherein each pulling means 20 is connected with one of the stacks 23. In this embodiment, the free end of the pulling means 20 can be attached to the bending component 16 to pull the pulling means 20 against the elastic counterforce of the preform element 7. Attachment means, in particular clamping means, of the bending tool 14 are provided to attach the bending component 16 and thus the free end of the pulling means 20 on the stationary component 15. Two bending components 16 can be guided along corresponding track-like guide means to allow different bending amplitudes of the bending section 9. Alternatively, instead of the bending tool 14, in Figure 8 the embodiment of the preform element 7, the pulling means 20 can be directly attached on the flange 17 or somewhere on the outside of the blade mould 8.

[0075] Figure 9 Details about the preform element 7 according to an embodiment of the application are shown, in particular Figure 2 one of the outermost preform elements 7. In Figure 9 one of the stacks 23 is shown, which is part of the bending section 9 and comprises several preform components 28. In Figure 9 the bending structure of the preform element 7 as shown in Figure 2 is not shown. In contrast to the remaining or rest of the respective preform element 7, the bending section 9 comprises a reduced stiffness. The preform element 7 comprises a laminate structure with several layered preform components 28, wherein an activated adhesive 22 (not shown) is present between the preform components 28. Figure 9(Not shown) Adhesives of adjacent prefabricated components 28 are adhered to each other. In the curved section 9, the adhesion between adjacent prefabricated components 28 is reduced or even non-existent compared to the rest of the prefabricated elements. The reduced adhesion is indicated by the dashed lines between the respective prefabricated components 28.

[0076] Next, refer to Figure 10 This describes in detail a method for manufacturing prefabricated element 7 according to an embodiment of the present invention. Figure 10 It shows Figure 9 The lower portion of the stack 23. Prefabricated components 28 are arranged on the surface 21 of the prefabricated mold of the prefabricated mold to form the stack 23, wherein an adhesive 22 is activated to adhere the prefabricated components 28 to each other. The adhesive 22 is preferably a powdered adhesive that can be activated by applying heat. The prefabricated components 28 are pad-shaped fiber sheets and are each made of a fabric having glass fiber, carbon fiber and / or aramid fiber impregnated with the adhesive 22.

[0077] Between two adjacent prefabricated components 28, a separating component 25 is arranged to prevent or hinder the adhesive 22 from adhering these prefabricated components 28 to each other during activation. As the separating component 25, two folded polymer foils protruding laterally from the prefabricated element 7 are provided. The polymer foils may be impermeable or perforated. After activation of the adhesive 22, the polymer foils are removed from the prefabricated element 7 by pulling the corresponding protruding segments of the polymer foils away from the prefabricated element 7. This process is carried out by… Figure 10 The corresponding arrow indicates this.

[0078] However, reduced adhesion between prefabricated components 28 can be achieved in other ways. Exemplarily, the amount of adhesive 22 in the curved segment 9 can be reduced compared to the rest of the prefabricated element 7. Additionally or alternatively, less heat can be applied during the activation of the heat-activated adhesive 22 compared to the rest of the prefabricated element 7. Reduced adhesion of the adhesive in the curved segment 9 can also be achieved after the adhesive 22 has been activated, i.e., by applying a mechanical load to the curved segment 9 after the activation of the adhesive 22. An external force can be applied to the curved segment 9 such that the activated adhesive 22 is at least partially decomposed, resulting in reduced adhesion. The external force or mechanical load can accordingly have mode I, II, or III, or a combination of these modes.

[0079] Figures 11 to 13 The steps of a method according to a second embodiment of the present invention are shown, which involves arranging a preformed element 7 in a blade mold 8 for further processing. In this embodiment, after the preformed element 7 has been placed on the mold surface of the blade mold 8, another preformed element 26 is placed on the mold surface of the blade mold 8.

[0080] The curved section 9 of the preform element 7 is a transverse section and comprises an upper protrusion 29 and a lower protrusion 30 tapering with a space in between. Thus, the curved section 9 has the shape of a crocodile mouth. A tapering transverse section 27 of the further preform element 26 is arranged in the space between the protrusions 29, 30. In the final blade 5, the transverse section 27 of the further preform element 26 is sandwiched between the protrusions 29, 30 of the preform element 7.

[0081] With regard to Figure 11 In this embodiment, the protrusions 29, 30 are elongated parallel to the plane of the mould surface of the blade mould 8. Next, the curved section 9 is bent according to Figure 12 The upper protrusion 29 is bent upwards away from the mould surface of the blade mould 8. However, it is also possible that the curved section 9 initially already comprises a provisional shape such that no bending process is required to change the situation shown in Figure 11 to the situation shown in Figure 12 .

[0082] Next, the further preform element 26 is placed transversely to the preform element 7 on the mould surface of the blade mould 8. A corresponding movement path 12 leads from above onto the mould surface (see Figure 12 ). Next, the curved section 9 is bent such that it overlaps the transverse section 27 of the further preform element 26, as shown in Figure 13 . The protrusions 29, 30 and the curved section 27 of the further preform element 26 correspond to each other in their shape.

[0083] In the embodiment explained by means of Figures 11 to 13 , a specific case is described in which a double-scarf joint is present between the preform element 7 and the further preform element 26. However, other types of joints are also possible. For other types of joints, the curved section 9 of the preform element 7 is typically bent out of the way in order to place the further preform element 26.

[0084] Although the application has been described in detail with reference to preferred embodiments, the application is not limited to the disclosed examples, and other variants can be derived by the skilled person from the disclosed examples without departing from the scope of the application.

Claims

1. A method for arranging at least one blade construction prefabricated element (7) in a blade mold (8) for further processing, comprising the following steps: a) Place at least one prefabricated element (7) on the mold surface of the blade mold (8), b) By moving at least one additional preformed element (26) and / or at least one blade component and / or at least one manufacturing tool (10) in the direction of movement along the movement path (12), the at least one additional preformed element (26) and / or the at least one blade component and / or the at least one manufacturing tool (10) are placed on the mold surface and / or the at least one preformed element (7), and c) Bending at least a portion of at least one bent segment (9) of the at least one prefabricated element (7) such that the at least one bent segment (9) overlaps at least partially with the at least one additional prefabricated element (26) and / or the at least one blade component and / or the at least one manufacturing tool (10), such that the at least one bent segment (9) blocks the at least one additional prefabricated element (26) and / or the at least one blade component and / or the at least one manufacturing tool (10) from moving in the opposite direction along the movement path (12).

2. The method according to claim 1, characterized in that, In step a), at least one bent segment (9) of the at least one preformed element (7) placed on the surface of the mold blocks the movement path (12) of the at least one additional preformed element (26) and / or the at least one blade component and / or at least one manufacturing tool (10), wherein, between step a) and step b), the at least one bent segment (9) is bent such that the at least one bent segment (9) does not block the movement path (12).

3. The method according to claim 1 or 2, characterized in that, In step a), the at least one preformed element (7) placed on the surface of the mold is configured as an upwardly open U-shaped overall profile, the U-shape including an outer end as the curved section (9) and protruding above the blade mold (8), wherein the at least one manufacturing tool (10) is a mandrel (11), in step b), the mandrel (11) is placed above the at least one preformed element (7) via a movement path (12) guided through the open end of the U-shape.

4. The method according to claims 2 and 3, characterized in that, In step a), at least one of the outer ends of the U-shape is bent such that the outer end faces the other outer end, thereby blocking the movement path (12), wherein, between step a) and step b), at least one of the outer ends is bent away from the other outer end such that the outer end does not block the movement path (12).

5. The method according to any one of the preceding claims, characterized in that, In step b), the at least one additional preform (26) is placed laterally relative to the at least one preform (7) on the mold surface, wherein the at least one curved segment (9) is at least one lateral segment of the at least one preform (7), wherein in step c), at least a portion of the at least one curved segment (9) is bent such that it overlaps with at least one lateral segment (27) of the at least one additional preform (26).

6. The method according to claims 2 and 5, characterized in that, In step a), at least a portion of the at least one bent segment (9) extends parallel to the plane of the mold surface, wherein, between step a) and step b), the at least a portion of the at least one bent segment (9) bends upward away from the mold surface such that it does not obstruct the path of movement (12) leading from above to the mold surface.

7. The method according to any one of the preceding claims, characterized in that, At least one of the at least one curved segment (9) has reduced stiffness compared to the rest of the corresponding prefabricated element (7).

8. The method according to any one of the preceding claims, characterized in that, The at least one prefabricated element (7) includes at least one protruding and flexible, particularly rope-like, strip-like or pad-like, pulling device (20), wherein the bending of the at least one bending segment (9) is performed by pulling the at least one pulling device (20) against the reaction force of the corresponding prefabricated element (7) and attaching the free end of the at least one pulling device (20) to a stationary part, particularly to the upper transverse flange (17) of the blade mold (8).

9. The method according to any one of the preceding claims, characterized in that, After step c), the at least one prefabricated element (7) and the at least one additional prefabricated element (26) and / or the at least one blade component are adhered to each other, particularly by injecting resin into and / or onto these components.

10. A prefabricated element to be used in the method according to any one of the preceding claims, said prefabricated element comprising at least one curved segment (9), particularly a transverse curved segment (9), said curved segment (9) having reduced stiffness compared to the remainder of said prefabricated element (7), wherein, The prefabricated element (7) includes a laminated structure having a plurality of layered prefabricated components (18), wherein an activated adhesive (22) adheres adjacent prefabricated components to each other, wherein in the at least one curved segment (9), the adhesion between at least two adjacent prefabricated components (18) is reduced or not formed compared to the rest of the prefabricated element (7).

11. A method for manufacturing the prefabricated element (7) according to claim 10, characterized in that, Multiple prefabricated components (18), particularly cushion-shaped and / or rigid, are arranged on the surface (21) of the prefabricated mold to form a stack, wherein an adhesive (22) of at least one of the prefabricated components (18) is activated to adhere adjacent prefabricated components (18) to each other, wherein, in particularly transverse curved sections (9) of the stack, - A separation element (25) is arranged between at least two adjacent prefabricated components (18) to prevent or hinder the adhesive (22) from adhering these prefabricated components (18) to each other during activation, and / or - The amount of adhesive (22) is reduced compared to the rest of the prefabricated element (7), and / or - Less heat is applied during the activation of the heat-activated adhesive (22) compared to the rest of the prefabricated element (7), and / or - After the adhesive (22) is activated, a mechanical load is applied to reduce the adhesiveness of the adhesive (22).

12. The method according to claim 11, wherein, The separating element (25) is arranged between at least two adjacent prefabricated elements (18), characterized in that the separating element (25) is a polymer foil, wherein the polymer foil is removed from the prefabricated element (7) after the adhesive (22) is activated, in particular by pulling the protruding segments of the polymer foil away from the resulting prefabricated element (7).

13. A bending tool for a blade mold (8) or yoke, comprising a fixing part (15) and a bending part (16), wherein, The fixing member (15) is capable of being attached to or attached to the blade mold (8) or the yoke, wherein the bending member (16) is movably mounted on the fixing member (15) such that, in the state where the bending tool (14) and at least one preform (7) are held by the blade mold (8) or the yoke, during the movement of the bending member (16), the interaction between the bending member (16) and the bending segment (9) of the at least one preform (7) causes the at least one preform (7) to bend.

14. The bending tool according to claim 13, characterized in that, The bending component (16) includes a cross section having at least two rods angled relative to each other, wherein one of the rods (18) is movably mounted on the fixing component (15) in its longitudinal direction, wherein, for the bending tool (14) to be held by the blade mold (8) or the yoke, the other rod (19) is adapted to grip the bending segment (9) during its movement.

15. A prefabricated component processing apparatus comprising at least one bending tool (14) according to claim 12 or 13, wherein, The processing device is a yoke or blade mold (8) for lifting the preformed element (7), the blade mold (8) having a bending tool (14) specifically attached to the upper transverse flange (17).

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