Method for manufacturing a preform for a wind turbine blade, manufacturing structure for manufacturing a preform for a wind turbine blade, and mould for manufacturing a structure

Abstract

Method for manufacturing a preform for a wind turbine blade, with the following steps: - providing a mold (1) and arranging a preform build material (7) in a transferable mold element (3) removably arranged on a mold carrier (2); - fixing the preform build material (7) in the mold element (3); - removing the mold element (3) with the fixed preform build material (7) from the mold carrier (2) and transferring it into a heating device (21); - heating the preform build material (7) for producing the preform; - removing the mold element (3) with the preform from the heating device (21) and cooling the preform.

Description

Technical Field

[0001] This invention relates to a method for manufacturing preforms for wind turbine blades. Background Technology

[0002] As is well known, wind turbines typically consist of multiple turbine blades attached to a hub. These blades interact with the wind, causing the hub to rotate. A generator is coupled to the hub and driven by the rotating hub. Modern turbine blades are enormous in length and width. Therefore, their manufacture is difficult due to the handling of large components. One technique for producing such large blades uses preforms, which are pre-formed smaller blade parts used to build the corresponding blade shell. These preforms are arranged and aligned according to the overall geometry required by the blade and are ultimately joined together, and accordingly embedded in fiber pads and resin, etc., for use in manufacturing the final large blade or blade part.

[0003] Each preform is prefabricated in a specific mold, typically having a slightly curved geometry with a length of, for example, 10-12 m and a width of, for example, 3-5 m. The mold includes corresponding mold sections in which preform building elements, such as fiber pads and adhesives, and optionally core elements are arranged. These elements are secured in a corresponding mold part having a defined geometry corresponding to the desired blade geometry by applying a vacuum. For this securing, the preform building elements are, for example, covered with foil, such that a vacuum can be applied to the space between the foil and the mold part in which the building elements are arranged. Heat is then supplied to the building elements to melt the locally positioned adhesive for locally securing the fiber pads and core elements, etc., by gluing them into an adhesive matrix provided by the molten adhesive. After this heating operation, the preform needs to be cooled to room temperature, after which it is sufficiently stable to be handled by a lifting device or any other similar processing or lifting device, typically a vacuum suction lifting device.

[0004] This method of producing preforms is quite cumbersome. The molds used to produce preforms are very complex in their setup, especially because each mold requires a heating and cooling system. This makes the molds very expensive, given the need for a large number of individual molds, as typically at least twenty or more preforms are needed to produce blades or blade components. Furthermore, since the corresponding mold geometry is designed for the corresponding geometry of the preform, significant rework of the molds is required when the preform geometry needs to be changed, necessitating adjustments to the heating and cooling equipment.

[0005] Furthermore, since both heating and cooling processes occur while the preform building elements or corresponding thermoformed preforms are arranged in the mold, the mold is occupied. Because the heating and cooling processes take a considerable amount of time, the entire mold becomes clogged during these lengthy procedures, resulting in extremely low productivity. This is further amplified because the mold cannot be preheated. Therefore, temperature processing must begin at room temperature, as all building elements need to be individually arranged in the mold before heating can begin, prior to vacuum solidification. Additionally, it is necessary to cool the thermoformed preform to room temperature to ensure its stability when processed using lifting equipment. Moreover, the time the corresponding mold is occupied can be extended, as sometimes, when no storage capacity is provided, the preform is not immediately removed after cooling but remains in the mold for a certain period.

[0006] Finally, after the preform is ejected from the mold, the mold surface needs to be thoroughly cleaned for the next manufacturing process; this cleaning step is also time-consuming. The mold remains unusable until this cleaning step is completed. Summary of the Invention

[0007] Therefore, one object of the present invention is to provide an improved method for producing preforms for wind turbine blades.

[0008] To achieve this objective, the present invention provides a method for manufacturing preforms for wind turbine blades, comprising the following steps: - Provide a mold and arrange the preform building material in a transferable mold element that is removably arranged on a mold carrier. - Secure the preform building material shown to the mold element. - Remove the mold element with the fixed preform building material from the mold carrier and transfer it to the heating device. - Heating the preform building material to produce the preform. - Remove the mold element having the preform from the heating device and cool the preform.

[0009] According to the present invention, a specific new mold type is used to manufacture preforms. This mold type includes a mold carrier to which mold elements are removably fixed, the mold elements providing mold surfaces corresponding to the geometry of the preform to be constructed. Therefore, the mold elements are transferable and removable from the carrier. The mold itself or the corresponding mold elements are used only for arranging and fixing the building material thereon. Immediately after placing and fixing the building material, the transferable mold elements are removed from the mold carrier and transferred to a heating device, such as a heated oven, in which the building material is heated, and accordingly, an adhesive is melted and / or activated to fix, adhere, or accordingly glue fibrous materials such as fiber pads and / or core elements into the bonding matrix. After this heat treatment, the preform is cooled to, for example, room temperature by a cooling treatment, after which the final preform can be lifted from the transferable mold elements using appropriate lifting equipment.

[0010] Throughout the manufacturing process, the build material or corresponding preform is arranged on a movable mold element and thus moves between respective manufacturing stations as the mold element moves. Because the mold element is plate-shaped with a tray-like element surface, the overall construction of the mold element and the build element or corresponding preform itself is quite thin and therefore very easy to handle. After the build material has been placed and fixed, for example by vacuum fixation, the plate-shaped or tray-shaped mold element can be removed from the mold carrier and transferred to a heating device for further processing.

[0011] The method of the present invention exhibits several advantages. Since the mold itself is used only for arranging the building material on the mold elements and for securing it to the mold elements, no heating or cooling processes are performed within the mold. Therefore, the mold design is very simple, as there is no need to install heating or cooling equipment at the mold. Furthermore, since the mold carrier, which may be a frame-like carrier or the like, is not exposed to any heating or cooling, it will be dimensionally stable and last longer because it only supports the mold elements and the building material.

[0012] Because encapsulation is performed only in the mold and the mold element is removed immediately after encapsulation, a new mold element can then be placed on the mold carrier. This allows for the immediate commencement of placing new build material onto mold elements in the same mold that was previously occupied for a short period. This allows for a significant increase in throughput and capacity. Since a specific number of individual molds are typically provided, ongoing production can be achieved, as only a corresponding number of individual mold elements interchangeable with the corresponding mold carriers are required.

[0013] Since only the mold element with fixed building material needs to be removed from the mold carrier for further processing, no specific lifting device is required at the mold, as the plate or tray mold element can be removed from the mold carrier simply by a linear pushing or pulling action.

[0014] Since heating is performed in a separate heating device independent of the mold, and this device is used only to heat the building material, the heating device or corresponding oven can be preheated so that it is constantly maintained at the appropriate processing temperature. Preferably, the heating device has a capacity such that multiple plate-shaped or tray-shaped mold elements with building material can be arranged simultaneously in the heating device or corresponding oven, which further helps to increase the capacity and throughput of the manufactured structure. The building material is heated to a temperature of, for example, 80°-100°.

[0015] Furthermore, handling is improved because the building material or corresponding preform is arranged on a movable mold element throughout the manufacturing process, as it does not need to come into contact with the preform element at any time until its final production. Additionally, since the mold element, along with a vacuum cover such as foil, provides excellent protection for the preform, the mold element containing the preform can be stored in stock after the cooling process. Therefore, the preform is protected from contamination by dust particles, moisture penetration, and / or material degradation.

[0016] When a preform is removed from a mold element, the mold surface of the mold element can receive surface treatment immediately before it is placed back onto the mold carrier. Because the system includes multiple mold elements, there is always a clean mold element immediately after a mold element with fixed build material is removed from the mold carrier, allowing a new mold element to be placed on the mold carrier and a new cycle to begin.

[0017] The method of the present invention allows for significantly higher throughput in the production of preformed components because the steps of arranging and fixing the building material are performed directly at the mold, while the heating and cooling steps are separate and performed only using the molded components with the fixed building material removed.

[0018] As mentioned, the mold element is a multifunctional element. It serves as a receiving element, receiving the build material and defining the shape and / or form of the build material arrangement. It further functions as a fixing element, as it is used together with the vacuum foil to fix the build material. Additionally, it serves as a conveying element, as it is removed and conveyed from the mold carrier through subsequent manufacturing stations, thereby always ensuring that the fixed build material or preform retains its shape. To achieve these multifunctional characteristics, a mold is used, comprising a mold carrier with a removable rigid tray-like mold element providing a mold surface on which the build material is arranged. According to this embodiment, the mold element itself is rigid and its form is completely stable. It is preferably made of a plate, which is formed or processed to provide a corresponding mold surface on which the build material is arranged. The mold element or the corresponding plate can be made with a thickness of, for example, 2-5 cm. Because the mold element itself is rigid, it is form-stable and heat-resistant even at high temperatures, i.e., much higher than the temperatures applied in the heating device, thus ensuring the stability of the vacuum-fixed build material, as the mold element itself provides this stability, even though the build material is firmly fixed by vacuum.

[0019] As mentioned, the building elements may include at least fibrous material, preferably in the form of a fiber mat, whether it is a glass fiber or carbon fiber mat, and both types of mats can be used to build preforms. Furthermore, the building materials include an adhesive, which is typically in the form of a bonding powder, granules, or the like, but may also be a liquid or hot-melt based adhesive, which is typically applied locally below, between, or above the respective fibrous material or fiber mat. Additionally, one or more core elements may be selectively arranged, for example, core elements made of wood such as balsa wood or foam such as synthetic foam or the like. The stack is locally secured by molten adhesive to maintain its openness during the manufacturing process of the turbine blade or blade component, allowing for resin impregnation.

[0020] As mentioned, the preform build material is secured to the mold element by covering the preform build material with at least one vacuum cover and applying a vacuum. The vacuum cover is preferably a vacuum foil, which is completely placed on the build material and overlaps the mold element regardless of its type. By applying a vacuum between the mold element and the vacuum cover, the space between them where the build material is arranged is vented, and the vacuum cover is drawn towards the mold element, thereby securing the stacked build material.

[0021] Preferably, the established vacuum is maintained during any subsequent processing step, and in particular released only at the earliest after the heating process, but may also be maintained throughout the cooling process, and even released only before the preform element is released from the mold element, and even only before the preform element is used and placed in the blade mold. The vacuum is preferably established using a suitable vacuum device, such as a pump connected to a hose and a valve attached to a vacuum cover, thereby allowing the vacuum device to be coupled and disconnected. Thus, the established vacuum can be checked during or before any subsequent processing step, for example, using a suitable pressure measuring device such as a pressure gauge. If the pressure exceeds a certain threshold, the vacuum device can be used to return the vacuum to the desired level. The use of, for example, hoses and valves also provides the option of blowing air into the vacuum cover to facilitate the release of the cover from the mold element and / or preform build material or preform element after the heating or cooling processing step.

[0022] As mentioned, after the build material is arranged and secured to the mold element, the mold element itself is removed from the mold carrier to transfer it to the heat treatment. To transfer the mold element to the heating device, the mold element with the fixed preform build material is transferred from the mold carrier to a mold conveying device and stored in the conveying device until it is conveyed to the heating device, or directly conveyed to the heating device. According to this embodiment, a mold conveying device is provided, adapted to receive at least one mold element with corresponding fixed build material. This conveying device can now act as a buffer, allowing the storage of at least one mold element, or multiple mold elements if adapted to store more than one, until they will be further processed in the heating device. Alternatively, the conveying device can directly convey one or more mold elements to the heating device.

[0023] Preferably, more than one mold element can be transferred to a common, preferably rack-like, conveyor. Therefore, this conveyor is adapted to receive a specific number of mold elements having preform building material, for example, five to ten. The conveyor or corresponding rack has, for example, corresponding compartments arranged vertically stacked, with each compartment receiving one mold element. This allows a larger number of mold elements to be stored in the rack-like conveyor for buffering purposes, or for directly and simultaneously moving a larger number to the heating device.

[0024] To collect multiple mold elements in a pallet-shaped conveyor, the conveyor moves from a first mold carrier for receiving a first mold element to one or more additional mold elements. For this purpose, the conveyor can move or be moved on corresponding tracks or guides arranged in or on the floor, for example, along a row of individual molds or mold carriers, to collect the respective mold elements for further processing.

[0025] After the conveying device has received one or more mold elements, they are transferred directly or after a certain delay to the heating device. Several alternatives are possible for moving the mold elements into a heating device such as an oven. According to a first alternative, the conveying device with one or more mold elements is moved into the heating device. Here, the conveying device with the mold elements is itself moved into the oven and remains there with them throughout the heating process. In an alternative embodiment, one or more mold elements are moved from the conveying device into the heating device. Here, the conveying device moves to a transfer position where the mold element, or each mold element, is transferred from the conveying device into the oven for heating. In this embodiment, the conveying device can immediately return and begin collecting mold elements again. In this embodiment, the heating device or the corresponding oven has separate compartments for receiving mold elements, as preferably, the oven has dimensions that allow for the simultaneous processing of an expanded number of mold elements. Thus, it is sized and includes a specific number of compartments to receive a corresponding number of mold elements, or it is sized to receive the entire conveying device with mold elements. In any case, the oven can be designed to accommodate multiple mold elements or mold element conveying devices placed in parallel or extending sequentially to each other. After heat treatment, the mold elements or the corresponding now-produced preforms need to be cooled. Although the initial steps regarding the arrangement and fixation of the building materials are performed solely on the mold, subsequent processing is separate from the mold, and the cooling process is also separate from the heating process or the corresponding oven. This means that the hot preforms and mold elements will not remain in the oven during the cooling process, which allows the heating device to be reused immediately after the mold elements are removed from the oven.

[0026] The cooling process can also be performed in various ways. One or more mold elements can be removed from the heating device after heating and cooled in ambient air. According to this embodiment, the mold elements with the hot preform are simply removed from the oven and placed in a cooling area or the like, and thus cooled in ambient air. To avoid the temperature within the manufacturing facility becoming too high due to this cooling, ambient air cooling should be carried out in an area outside the manufacturing building. In an alternative to ambient air cooling, the mold elements can be moved into a cooling device. Specific cooling devices for performing active cooling are provided here. Similar to the heating device, which can be an oven with a corresponding heat source, the cooling device can also be a housing with a corresponding cooler such as a cooling fan or the like. If the heating device and the cooling device are placed close to each other, for example, an energy recycling can be established because the heat dissipated from the cooled preform can be transferred to the heating device.

[0027] As already mentioned, the conveyor, i.e., the frame, can be moved into the heating unit together with, preferably, multiple mold elements, or only the individual mold elements can be moved into the heating unit. If the entire frame is in the oven, it is preferable to remove only the entire frame with all the mold elements from the oven, but it is also possible to remove the individual elements from the frame. If the individual mold elements are placed separately in the oven, they can be similarly removed from the oven separately. By removing the discrete mold elements from the oven, this allows for differential heating of the respective mold elements and their preform building materials, depending on their respective settings; for example, one preform may require a longer heat treatment while another preform requires a shorter heat treatment. Thus, introducing individual mold elements into the oven and then removing them again provides greater flexibility regarding the heating process.

[0028] Because of these various ways of arranging the mold elements in the heating device, various embodiments regarding the transfer for the next cooling step are also feasible. According to a first alternative, a conveyor comprising one or more mold elements is transferred to a cooling device. Here, the occupied conveyor or corresponding rack is in the oven, and thus the entire conveyor with the hot mold elements and preforms is moved from the oven into a cooling device such as a cooling chamber or the like. Preferably, corresponding tracks or other types of guides are provided to allow for easy transfer of the rack from the oven to the cooler.

[0029] In an alternative embodiment, one or more mold elements are transferred from the heating device to a conveying device or another conveying device, wherein the conveying device is held or moved into ambient air for cooling, or wherein the conveying device is moved to a cooling device, wherein one or more mold elements are transferred into the cooling device, or the conveying device is moved into the cooling device. In this alternative, individual mold elements arranged in the oven are transferred to and collected thereon by a separate conveying device arranged at the outlet of the heating device. This conveying device, like a conveying device arranged between the mold and the heating device, is adapted to receive a corresponding number of mold elements and their preforms. Depending on the cooling process, both variations are feasible. First, the conveying device is held or moved into ambient air for cooling. Here, the rack with the preforms remains close to the heating device or is moved to a specific cooling area where ambient air cooling is performed. In an alternative, the conveying device is moved to a cooling device, i.e., a specific ventilated cooler or the like, wherein individual mold elements are removed from the conveying device and transferred into the cooling device, wherein corresponding separate compartments are arranged for receiving them. In an alternative, the entire conveying device may be moved into the cooling device. In any case, the cooling device can be designed to accommodate multiple mold elements or mold element conveying devices placed parallel or extending to each other.

[0030] Finally, the mold elements themselves can be directly transferred from the heating unit to the cooling unit. The heating and cooling units are arranged in a row and equipped with corresponding conveying devices, allowing the mold elements with preforms to be moved directly from the heating unit to the cooling unit. These conveying devices can also be rails, roller guides, or the like.

[0031] Clearly, there are several possibilities for bringing the corresponding hot mold elements with hot preforms to a cooling device or cooling area.

[0032] After cooling, the corresponding manufactured preforms are removed from the mold elements. This is preferably performed by a lifting device, preferably a vacuum lifting device. Using this device, the corresponding preforms are moved to a storage side or directly further processed, wherein the preforms are arranged in a large blade mold for the final production of blades. If the mold elements with preforms are arranged on a conveyor, they need to be removed from the conveyor; for this purpose, they can be transferred, for example, to a conveyor or the like, by which they are conveyed to the lifting device. In the absence of ambient air cooling, this may require definitively removing the occupied rack from the cooling unit, and correspondingly removing the individual mold elements with preforms from the cooling unit.

[0033] Vacuum caps or similar and / or release membranes (if used) are eventually removed from the preform element after the preform has cooled, for example, before the preform is placed in the blade mold.

[0034] The present invention further relates to a manufacturing structure for a preform used in manufacturing wind turbine blades, the manufacturing structure comprising: - One or more molds, each comprising a mold carrier and one or more designated mold elements, each mold element being adapted to fixably receive preform building material and removably disposed on the mold carrier. - A heating device adapted to receive at least one of the mold elements having the preform building material removed from the mold carrier.

[0035] Preferably, a relatively large number of molds are present, such as 5, 10, or 20 molds. Preferably, the number of mold elements is greater than the number of carriers, allowing the molds to be used permanently, because after removing a mold element with fixed preform building material, a new, clean (if needed) mold element can be immediately placed on the mold carrier, and new building material can be applied to the surface of the mold element. Therefore, for this ongoing cyclical process, a specific number of individual, interchangeable mold elements are required. Mold elements assigned to a common mold carrier can be all identical, such that the corresponding mold always produces the same type of preform element. However, of course, alternatively, mold elements can also be completely interchangeable between corresponding mold carriers.

[0036] Each mold element may be a rigid, tray-like mold element providing a mold surface adapted to receive preform build material, wherein the mold carrier includes mold element receiving devices. In this embodiment, the mold element itself is form-stable and, for example, made of a rigid and stiffened plate, which is accordingly machined to provide a corresponding mold surface on which the preform build material is disposed. The mold element may, for example, be 3D printed, i.e., additive manufacturing, casting, or forming pressing. The rigid mold element is removably placed on a mold carrier, which may be a simple frame-like carrier structure and provided with corresponding receiving devices. These receiving devices may, for example, be longitudinal rails or rods or the like, on which the rigid mold element is disposed with its longitudinal edges.

[0037] The rigid mold element may be made of metal such as aluminum, or of a sufficiently heat-resistant polymer or wood, and preferably may include a surface that is non-adhesive to the adhesive. If the surface is adhesive to the adhesive, a release film or similar release agent may be applied to the surface of the mold element before the preform building material is placed. The rigid element may have a thickness of, for example, 1-5 cm, depending on the material it is made of. Cleaning may be performed using a corresponding automatic cleaning device, preferably automatically transferred to the cleaning device after the preform is removed, and the cleaned mold element is then recycled back to the area with the mold carrier. Thus, it is a cyclical process that begins with the mold element placed on the mold section of the carrier, followed by the arrangement of the building material, then, for example, transfer to a conveyor, then the mold element is transferred to a heating device in the different manner described above, followed by a heating step, then a cooling step, which may also be performed in various ways, after which the preform is removed and further processed, while the emptied mold element is automatically cleaned and recycled back to the starting point of the processing cycle.

[0038] The manufacturing structure also includes at least one mold element conveying device adapted to receive one or more mold elements having fixed preform building elements for transferring the one or more mold elements to a heating device. Preferably adapted to receive multiple mold elements, this conveying device is used to convey one or more mold elements from a corresponding mold carrier to a heating oven. It includes corresponding receiving or securing devices for the corresponding mold elements, such as corresponding tracks or rods or the like, on which the edges of the mold elements are disposed. The conveying device may convey the mold elements directly to the heating device, or first convey them to a storage location and then subsequently to the heating device.

[0039] Furthermore, the mold element conveying device is adapted to receive rectangular mold elements by receiving them from the longitudinal element side or from the shorter element side. Therefore, the mold element can be inserted vertically into the longitudinal axis from the side or from the front along the longitudinal axis.

[0040] A mold element conveying device suitable for receiving multiple mold elements preferably includes a vertically movable mold element receiving device for vertically stacking multiple mold elements. Here, the conveying device or corresponding frame is equipped with a paternoster lift or the like, and thus any type of lifting device, which allows, for example, the retrieval of a first mold element at its lowest position, which is then lifted until a second mold element can be introduced, and both elements are subsequently lifted, etc. This lifting device can be, for example, a circulating chain, belt, or the like to which the corresponding receiving element is arranged. This configuration allows the mold elements to be easily slid (pushed or pulled) into the receiving device of the mold element conveying device with minimal or no effort. Therefore, only horizontal movement of the mold elements needs to be performed, which limits the need for mechanical or manual lifting of the mold elements.

[0041] The heating device itself can be adapted to receive one, preferably multiple, mold elements. Here, the mold element with building material is directly introduced into the oven. Alternatively, the heating device can also be adapted to receive a conveyor comprising one or more mold elements. In this embodiment, a complete frame with conveyor elements is moved into the heating device.

[0042] If the heating device is adapted to receive the mold elements themselves, it may include a vertically movable mold element receiving device for vertically stacking multiple mold elements. Similarly, the mold element receiving device may also be a lifting device, such as a bucket elevator or the like, which allows vertical movement of the mold elements for vertical stacking. Likewise, a first mold element may be received, for example, at its lowest position, after which it moves vertically a first distance, followed by the introduction of a second mold element, and then the two mold elements move vertically again, and so on. Again, this structure only provides horizontal movement of the mold elements, which limits the need for mechanical or manual lifting of the mold elements.

[0043] Furthermore, the structure may include a cooling device adapted to receive one or more mold elements having heated preforms for cooling. This cooling device allows for active cooling operations, such as removing heat using a cooling fan, and may be coupled to the heating device to establish energy recycling. The cooling device may be a cooling chamber or cooling box adapted to receive one, preferably multiple mold elements themselves, while the entire conveyor comprising one or more mold elements may also be received by the cooling device. Similarly, as with the heating device, only the mold elements having heated preforms may be received individually in the cooling device, or the occupied conveyor or corresponding frame may be received in the cooling device.

[0044] In this case, the conveyor received by the cooling unit may be a conveyor previously located in the heating unit. According to this embodiment, the conveyor or corresponding rack is transferred directly from the oven to the cooler, for example, automatically and via a track. Alternatively, if the oven has already received individual mold elements, the conveyor is adapted to receive one or more mold elements from the heating unit.

[0045] If the cooling device is adapted to receive the mold elements themselves, it may preferably include a vertically movable mold element receiving device for vertically stacking multiple mold elements. Furthermore, the cooling device may be equipped with lifting devices, such as bucket elevators or any other type of lifting device, adapted to retrieve individual mold elements. Similarly, they may be received from a conveyor at a lower position, after which the first mold element is lifted to a second position, where another mold element is received, and so on. Likewise, this configuration only provides horizontal movement of the mold elements, which limits the need for mechanical or manual lifting of the mold elements.

[0046] As mentioned above, specific transfers of mold elements from one location to another or from one article to another can be performed. To facilitate these transfers, transfer devices are provided for transferring mold elements from a mold carrier to a conveying device and / or from a conveying device to a heating device and / or from a heating device to another conveying or cooling device, or from another conveying device to a cooling device. Regardless of the arrangement, transfer devices are provided to facilitate transfer from one part of the structure to a subsequent part. Preferably, these transfer devices operate automatically, but may also involve partial manual operation, such as pushing or pulling. Thus, these transfers are preferably completed automatically by means of a corresponding drive motor or the like, while in some cases some manual handling is also possible.

[0047] The transfer device itself may include pushing devices arranged at the mold and / or conveying device, and / or pulling devices arranged at the conveying device and / or heating device, and / or rolling elements arranged at the mold and / or the conveying device carrying the mold element. These pushing or pulling devices may include specific pushing or pulling rods or the like that can be automatically coupled to mold elements pushed or pulled by, for example, a motor drive. Furthermore, rolling elements may also be arranged on corresponding guide rails or the like, thereby allowing easy movement of heavier mold elements with building material or preforms, which can also be initiated at least manually by pushing or pulling, as the rolling elements allow for very smooth and gentle movement. It should be noted that, regardless of the type of transfer device provided or the type of transfer device provided, the mold element is preferably locked to the corresponding device by locking elements. Thus, the mold element is, for example, releasably locked to a mold carrier or conveying device or a corresponding mold element receiving device in a heating oven or cooling unit. These locking devices can automatically engage when the mold element is in place and can also automatically disengage when it is to be removed.

[0048] As mentioned, the conveying device, or each conveying device, is preferably used to collect multiple mold elements from a corresponding mold carrier, or to move them to a heating device or from a heating device to a cooling device, etc. Preferably, each conveying device is capable of automatic movement along a corresponding guide rail. These preferably floor-based rails ensure a defined and safe path.

[0049] Finally, the present invention relates to a mold for manufacturing structures as described above. The mold is characterized by a mold carrier and at least one interchangeable mold element, which is a rigid tray-shaped mold element providing a mold surface suitable for receiving preform building material, wherein the mold carrier includes a mold element receiving device.

[0050] Since the building material is vacuum-fixed to the mold element, the mold carrier also includes a corresponding vacuum fixing device for fixing the building material to the mold element using a vacuum cover, such as foil, vacuum pad or the like, preferably foil, because it is lightweight and easy to handle.

[0051] Finally, the mold includes a transfer device for moving mold elements from the mold carrier, the transfer device preferably including a preferably automatic pushing device and / or rolling element arranged on the mold carrier. Attached Figure Description

[0052] Other objects and features of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings. However, the drawings are merely schematic diagrams designed for illustrative purposes only and do not limit the invention. The drawings show: Figure 1This is a schematic diagram of the mold of the present invention according to the first embodiment. Figure 2 This is a schematic diagram of the mold of the present invention, which has a conveying device for receiving mold components. Figure 3 It is a schematic diagram of the manufacturing structure. Figure 4 This is a schematic diagram of a second alternative for transferring mold components into heating and cooling devices. Figure 5 This is a schematic diagram of a third alternative for transferring mold components into heating and cooling devices. Figure 6 This is a schematic diagram of a fourth alternative for transferring mold components into heating and cooling devices, and Figure 7 This is a schematic diagram of the manufacturing structure of the second embodiment. Detailed Implementation

[0053] Figure 1 A schematic diagram of a mold 1 for manufacturing preforms of wind turbine blades is shown. The mold 1 includes a mold carrier 2 to which removable or interchangeable mold elements 3 are attached. The mold carrier 2 includes corresponding receiving elements 4, such as longitudinal tracks, beams, or the like on which the mold elements 3 are mounted. These elements are secured to the receiving elements 4 by corresponding locking elements that are released when the mold elements 3 should be removed.

[0054] The mold element 3 includes a tray-shaped recess 5 having a mold surface 6 on which building material 7 for constructing a preform is arranged. The building material 7 includes fibrous materials, such as fiber mats made of glass or carbon fiber, and binders, typically in powder or granular form. However, liquid or hot-melt binders may also be used. The building material 7 is arranged in a corresponding order or in the desired amount, wherein the building material 7 clearly follows the tray-shaped form of the mold surface 6.

[0055] After all the building materials are arranged on surface 6, a vacuum cover 8 is arranged, which overlaps with the building materials 7 and also extends onto surface 6 of the mold element 3, as shown. Figure 1 As shown. The mold carrier is equipped with a vacuum fixing device 9, which includes a vacuum pump and a corresponding hose or similar with a valve that allows the device 9 to be coupled to and disconnected from the mold element 3, thereby allowing a vacuum to be created between the mold element 3 and the vacuum cover 8 to empty the space between them, where the building material 7 is arranged. This evacuation or vacuum fixing secures the building material 7 very tightly to the mold element 3.

[0056] The mold element 3 itself is a rigid plate-shaped element, made of a corresponding rigid plate of metal (such as steel, aluminum, etc.) or of a heat-resistant and form-stable plastic during the subsequent heating process. For example, this steel or aluminum plate is shaped accordingly to prepare a tray-shaped or convex mold surface 6.

[0057] As mentioned, mold element 3 can be removed from mold carrier 2. After vacuum fixing of the building material 7, mold element 3 with the fixed building material 7 can be removed, and vacuum cover 8 can be removed after separating it from vacuum fixing device 9, while maintaining a vacuum between mold element 3 and vacuum cover 8, thus also maintaining the fixing of the building material. Mold element 3 can now be moved to heating device for further processing. Only mold carrier 2 remains in place, and another new and clean mold element 3 can be provided, on which new building material 7, etc., can be placed immediately after the removal of the previous mold element 3.

[0058] according to Figure 1 The first embodiment, as mentioned above, includes a rigid and form-stable plate-shaped mold assembly 3, which is removably arranged on top of the mold carrier 2, for example, by lowering it onto the carrier 2 using a lifting device, or by pushing it onto the mold carrier 2 using a conveying device or by hand. Since the mold element 3 itself is rigid, it is easy to handle and no change in form or shape occurs during handling and further processing.

[0059] Figure 2 It shows according to Figure 1 The mold 1 of the present invention. The mold element 3, with vacuum-fixed building material, has been partially moved from the mold carrier 2. The receiving device 4 is equipped with a corresponding transfer device 14, in the form of a corresponding roller element 15, on which the mold element 3 rolls and can be easily pushed or pulled to transfer it to a conveying device 16, in the form of a frame 17. This conveying device 16 can move and be guided on corresponding tracks 18, such that, for example, it can move automatically along several molds 1 arranged side-by-side. Figure 3 Only one of these molds 1 is shown. The conveying device 16 is adapted to receive several of the mold elements 3 with vacuum-fixed building material 7. (As shown) Figure 3As shown, a mold carrier 2 from a mold 1 (not shown) has been received in a frame 17. The frame 17 includes corresponding receiving devices 19, which are in the form of longitudinal rods or carriers, for example, equipped with rollers or the like, to facilitate movement of mold elements thereon. Receiving devices 19, as indicated by arrow P1, are vertically movable, allowing a corresponding receiving device to be moved into position to receive a new mold element 3. Subsequently, receiving devices 19 with mold element 3 move vertically, and another receiving device 19 moves into position to receive another mold element 3. Mold elements 3, as indicated by arrow P2, are simply pushed into the frame 17 by corresponding pushing devices arranged at the carrier 2, and these pushing actions can also be performed manually, as the mold element 3 rolls on roller elements 15. They can also be pulled into the frame 17 by corresponding pulling devices arranged at the frame 17. For example, these pushing or pulling devices can be pushing or pulling rods or the like.

[0060] The vertical movement of the receiving device 19 can be performed by a corresponding electric motor coupled to the receiving device 19, or by, for example, driving a circulating chain or belt, or a corresponding spindle driver or the like. Furthermore, the corresponding pushing or pulling device can also be a driven motor.

[0061] Figure 3 A first embodiment of the manufacturing structure 20 of the present invention for producing preforms of turbine blades is shown. In this example, three molds 1 are shown arranged side-by-side. Mold 1a is equipped with a new mold element 3a, see arrow P3, which is pushed or otherwise placed on a mold carrier 2a. A second mold 1b is equipped with a mold element 3b arranged on the mold carrier 2b. Building material 7b has been arranged on the mold element 3b, but has not yet been vacuum-fixed, for example.

[0062] Finally, the mold element 3c of the third mold 1c is prepared for further processing and, therefore, as indicated by arrow P4, is moved into the conveyor 16 or the corresponding rack 17. Mold element 3c comprises building material 7 covered by a vacuum cover 8c, which is thus vacuum-fixed. As shown, it has been partially moved into rack 17, in which two other mold elements 3d and 3e are already arranged.

[0063] The frame 17 moves along the corresponding track 18 in the direction of arrow P5, and thus along the corresponding mold 1. At each mold 1, a corresponding mold element 3, including the fixed building material, is received on the corresponding receiving device 19 of the frame 17 until the frame 17 is fully loaded. The frame 17 then moves to the heating device 21, i.e., a heated oven, which can be preheated or correspondingly always maintained at the specific temperature level required to melt the binder, which is usually only applied locally, in order to embed all the fiber materials and core materials, etc., into the corresponding fluid bond matrix. Several mold elements are moved into the heating device 21, as indicated by arrow P6. In this illustration, several mold elements 3f, 3g are already in the heating device 21, which is only shown partially open for illustrative purposes. They are heated for the specific time required to build the preform. Several possibilities are possible regarding the manner in which the mold elements are inserted into the heating device, which will be explained later.

[0064] A cooling device 22 is further illustrated, such as a housing or unit including a cooling fan or the like, adapted to actively cool a heated preform transferred from the heating device 21 to the cooling device 22, as indicated by arrow P7. This transfer will also be described later. The mold element capacity of the cooling device 22 preferably corresponds to the mold element capacity of the heating device 21, such that all heated mold elements 3 can be transferred to the cooling device 22 and cooled simultaneously.

[0065] In the cooling device 22, the thermoformed parts are cooled to ambient temperature, after which they are removed from the cooling device 22 as indicated by arrow P8 for further processing.

[0066] As this principle layout clearly shows, mold 1 is used only for preparing the building material 7, for shaping the building material 7 according to the required preform shape, and for fixing the building material 7 to the corresponding mold element 3. Immediately after the corresponding mold element 3 is removed from the mold carrier, a new mold element 3 can be placed in place on the mold carrier, with the surface of the new mold element 3 completely clean, to ensure that the building material 7 can be properly arranged.

[0067] The heating process is completely separated from the mold area. Because heating is performed only in the heating device, this device can be maintained at a fixed temperature, which allows for very short heating operations.

[0068] The same applies to cooling device 22, which allows for separate cooling steps and can also be maintained at a specific cooling temperature or allowed to actively operate a specific cooling slope to enhance cooling.

[0069] Therefore, almost constant manufacturing can be achieved because the mold elements 3, ready for heating and cooling processes, can be provided consistently. The time the mold 1 is occupied is very short, almost equivalent to the time required to place a new mold element 3 in place, load and secure the building material 7, and remove the loaded mold element 3. Since both the heating device 21 and the cooling device 22 are adapted to receive several mold elements, the heating and cooling processes are also significantly faster because a certain number of mold elements can be processed simultaneously.

[0070] Figure 4 A first alternative for transferring the mold element 3 to the heating device 21 and the cooling device 22 is shown. In this embodiment, the mold element 3 is arranged in the conveying device 16, i.e., the frame 17, and is received on a corresponding receiving device 19, as indicated by the double arrow P9, which is vertically movable as previously mentioned.

[0071] In this embodiment, the complete conveyor 16, containing all mold elements 3, is moved into the heating device 21 and remains there during the heating process. When the heating process is complete, the conveyor 16 is removed from the heating device 21 and directly enters the cooling device 22 for final cooling. After the cooling step is completed, the entire conveyor 16, containing the cooled mold elements 3 including the cooled preform, is removed from the cooling device 22. The mold elements 3 can then be removed from the conveyor 16, and the finished preform can be removed from the mold elements 3 for further processing. Alternatively, the conveyor 16 can be moved to a storage area for storing the finished preform.

[0072] After the preform is removed, the mold element 3 will be automatically surface cleaned and automatically recycled so that it can be placed on the unloaded mold carrier 2 again.

[0073] exist Figure 5 In the embodiments shown again, the conveying device 16 or the corresponding frame 17 includes a plurality of mold elements 3 arranged on the corresponding vertically movable receiving device 19, as indicated by arrow P9.

[0074] The heating device 21 is equipped with a vertically movable individual receiving device 23, as indicated by double arrow P10. Individual mold elements 3 of the conveying device 16, as indicated by arrow P11, move horizontally from the conveying device 16 to the heating device 21, or correspondingly from the receiving device 19 to the receiving device 23. For example, only the lowest mold element 3 moves to the lowest position of the heating device 21. In the next step, the next mold element 3 of the conveying device 16 is lowered while the previous mold element received in the heating device 21 is raised, allowing a new transfer to begin until all mold elements are unloaded. Once unloaded, the conveying device 16 returns to receive new mold elements 3 again.

[0075] After the heating process is complete, the individual mold element 3 is transferred to the cooling device 22. The cooling device 22 is configured similarly to the heating device 21. Furthermore, the cooling device 22 also includes a receiving device 24, which, as shown by double arrow P12, is vertically movable. Again, using the corresponding transfer device, as indicated by arrow P13, the individual mold element 3 is moved from the heating device 11 or the corresponding receiving device 23 to the cooling device 22 or the corresponding receiving device 24. Furthermore, the corresponding vertical movement is also performed here.

[0076] After cooling is complete, the mold element 3 with the cooled preform is transferred to another conveying device 25, which is also a frame, and has a corresponding receiving device 26 for receiving the corresponding mold element 3, as shown by arrow P14. The receiving device 26, as shown by arrow P15, can also move vertically. Using this conveying device 25, the mold element 3 with the finished preform can be conveyed to a storage area or another processing device, etc.

[0077] It should be noted that the conveyor 25 is optional. Individual cooled mold elements 3 can, for example, be transferred to a corresponding conveyor belt or similar and conveyed to a storage area or to a lifting device for vacuum lifting of the finished preforms from the mold elements for further processing. The emptied mold elements 3 can then be surface-cleaned and recycled if necessary.

[0078] Figure 6 An embodiment with a first conveying device 16 is shown, which is arranged in conjunction with... Figure 5 The conveying device 16 is the same. Furthermore, the heating device 21 and the cooling device 22 correspond in their arrangement and function to... Figure 6The heating and cooling devices 21 and 22 are provided. In this embodiment, the heating device 21 and the cooling device 22 are spaced apart, so the mold elements cannot be transferred directly. For transfer, another conveying device 27 is provided, which includes a corresponding receiving device 28, such as a beam or rail, on which the individual mold elements 3 from the heating device 21 are received, as shown by arrow P16. Similarly, the receiving device 28 can also move vertically, as shown by arrow P17.

[0079] After loading is completed on the conveyor 27, which is also a frame, it moves to the cooling unit 22, where the individual mold element 3 is unloaded onto the corresponding receiving device 24 of the cooling unit 22, as indicated by double arrow P18. After the cooling step is completed, the mold element 3 can be transferred back to the conveyor 25, or directly to the conveyor belt, etc.

[0080] According to Figure 5 and Figure 6 In both embodiments, the mold elements 3 are individually transferred into and out of the heating unit. The order in which they are transferred into and out of the heating device 21 can be the same. This means that each mold element 3 receives the same temperature treatment or is correspondingly held in the heating device 21 for the same treatment time. Where mold elements 3 or their corresponding building elements require shorter or longer heat treatments, the corresponding mold element can be held in the heating device 21 for a shorter or longer time compared to other mold elements 3, allowing the transfer order to vary depending on the required treatment time. This is possible because individual mold element transfer is possible.

[0081] at last, Figure 7 Another layout of the manufacturing structure 20 is shown. In this example, it again includes four molds 1, each mold having a removable mold element 3. In order to arrange the building material 7 on the respective mold element 3, the building material 7 is arranged close to the respective mold 1 and unfolded, for example, from the respective fiber pad roll, while an adhesive is applied from the respective hopper or the like.

[0082] In this embodiment, a forklift-like conveyor 18 is positioned between the two rows of molds 1. This conveyor 16, or a corresponding forklift, is adapted to pick up the loaded mold elements 3 and transport them to the heating device 21, as indicated by arrow P19. The mold elements 3 are then transferred from the heating device 21 to the cooling device 22, and from there are further processed as described.

[0083] Then, after cleaning the surface of the mold element 3, the empty mold element 3 is returned by another conveying device 25, such as a forklift, so that it can be replaced on the mold carrier 2.

[0084] The figure also shows various tracks 18 on which conveyor devices 25 move, wherein the tracks 18 can also be used for corresponding conveyor vehicles 29 for distributing building materials.

[0085] Although the invention has been described in detail with reference to preferred embodiments, the invention is not limited to the disclosed examples, and other variations can be derived by those skilled in the art from the disclosed examples without departing from the scope of the invention.

Claims

1. A method for manufacturing a preform for wind turbine blades, comprising the following steps: - Provide a mold (1) and arrange the preform building material (7) on a removable mold element (3) arranged on a mold carrier (2). - Fix the preform building material (7) onto the mold element (3), - Remove the mold element (3) with the fixed preform building material (7) from the mold carrier (2) and transfer it to the heating device (21). - The preform building material (7) is heated to produce the preform. - Remove the mold element (3) with the preform from the heating device (21) and cool the preform.

2. The method according to claim 1, characterized in that, Using a mold (1), the mold (1) includes a mold carrier (2) having a removable rigid tray-shaped mold element (3), the mold element (3) providing a mold surface (6), on which the building material (7) is arranged.

3. The method according to claim 1 or 2, characterized in that, The mold element (3) or multiple mold elements (3) having fixed preform building material (7) are transferred from the mold carrier (2) to the first conveying device (16) and stored in the first conveying device (16) until it is conveyed to the heating device (21) with the first conveying device, or directly conveyed to the heating device (21) with the first conveying device (16).

4. The method according to claim 3, characterized in that, The first conveying device (16) moves from the first mold carrier (2, 2a) for receiving the first mold element (3a) to one or more additional mold carriers (2b, 2c) for receiving one or more additional mold elements (3b, 3c).

5. The method according to claim 3, characterized in that, The first conveying device (16) having one or more mold elements (3) is moved into the heating device (21), or one or more mold elements (3) are moved from the first conveying device (16) into the heating device (21).

6. The method according to claim 3, characterized in that, After the heating, the one or more mold elements (3) are removed from the heating device (21) and cooled in ambient air or moved into a cooling device (22).

7. The method according to claim 6, characterized in that, - The first conveying device (16), including the one or more mold elements (3), is transferred to the cooling device (22). - Alternatively, one or more mold elements (3) themselves are transferred from the heating device (21) to the second conveying device (27). - - Wherein, the second conveying device (27) is held or moved into ambient air for cooling, or - Wherein, the second conveying device (27) moves to the cooling device (22), wherein one or more mold elements (3) are transferred to the cooling device (22), or the second conveying device (27) moves into the cooling device. - Alternatively, one or more mold elements (3) themselves are transferred directly from the heating device (21) to the cooling device (22).

8. The method according to claim 1 or 2, characterized in that, The preform building material (7) is fixed onto the mold element (3) by applying a vacuum, wherein the vacuum is first released after the preform building material (7) has been heated.

9. The method according to claim 3, characterized in that, The first conveying device (16) is frame-shaped.

10. A manufacturing structure for preforms used in the manufacture of wind turbine blades, comprising: - One or more molds (1, 1a, 1b, 1c), each comprising a mold carrier (2, 2a, 2b, 2c) and one or more mold elements (3, 3a, 3b, 3c, 3d, 3e, 3f, 3g), each mold element being adapted to fixably receive preform building material (7) and removably arranged on the mold carrier (2, 2a, 2b, 2c). - A heating device (21) adapted to receive at least one of the mold elements (3, 3a, 3b, 3c, 3d, 3e, 3f, 3g) having the preform building material (7) removed from the mold carrier (2, 2a, 2b, 2c).

11. The manufacturing structure according to claim 10, characterized in that, Each mold element is a rigid tray-shaped mold element (3, 3a, 3b, 3c, 3d, 3e, 3f, 3g) that provides a mold surface (6) adapted to receive the preform building material (7), wherein the mold carrier (2, 2a, 2b, 2c) includes a mold element receiving device.

12. The manufacturing structure according to claim 10 or 11, characterized in that, At least one first conveying device (16) is provided, the first conveying device (16) being adapted to receive one or more mold elements (3) having fixed preform building material (7) for transferring the one or more mold elements (3) to the heating device (21).

13. The manufacturing structure according to claim 12, characterized in that, The heating device (21) is adapted to receive one or more mold elements (3) themselves, or to receive the first conveying device (16) including one or more mold elements (3).

14. The manufacturing structure according to claim 10 or 11, characterized in that, A cooling device (22) is provided, which is adapted to receive one or more mold elements (3) having heated preforms for cooling them.

15. The manufacturing structure according to claim 14, characterized in that, The cooling device (22) is adapted to receive one or more mold elements (3) themselves, or to receive a first conveying device (16) comprising one or more mold elements (3).

16. The manufacturing structure according to claim 15, characterized in that, The first conveying device (16) is a device previously located in the heating device, or a second conveying device (27) adapted to receive the one or more mold elements from the heating device (21).

17. The manufacturing structure according to claim 15, wherein, The first conveying device (16) and / or the heating device (21) and / or the cooling device (22) are adapted to receive a plurality of mold elements (3) themselves, characterized in that the first conveying device (16) and / or the heating device (21) and / or the cooling device (22) include a vertically movable mold element receiving device for vertically stacking the plurality of mold elements (3).

18. The manufacturing structure according to claim 15, characterized in that, A transfer device (14) is provided for transferring mold elements (3) from the mold carrier (2) to the first conveying device (16) and / or from the first conveying device (16) to the heating device (21) and / or from the heating device (21) to the second conveying device (27) or the cooling device (22) or from the second conveying device (27) to the cooling device (22).

19. The manufacturing structure according to claim 18, characterized in that, The transfer device (14) includes a pushing device arranged at the mold and / or the first conveying device, and / or a pulling device arranged at the first conveying device and / or the heating device, and / or a roller element (15) arranged at the mold and / or the first conveying device that carries the mold element.

20. A mold for manufacturing a structure according to claim 10 or 11, characterized in that... The mold carrier (2) and at least one interchangeable mold element (3), the mold element (3) being a rigid tray-shaped mold element (3) providing a mold surface (6) adapted to receive preform building material (7), wherein the mold carrier (2) includes a mold element receiving device.

21. The mold according to claim 20, characterized in that, The mold includes a transfer device (14) for moving the mold element (3) from the mold carrier (2).

22. The mold according to claim 21, characterized in that, The transfer device (14) includes a pushing device and / or a roller element (15) arranged on the mold carrier.

Images