ARRANGEMENT, METHOD AND TOOL FOR FASTENING COMPONENTS

Description

[0001] The present invention relates to an assembly and a method for fastening a component. It relates to fastening elements in which an insert is glued into a prefabricated hole in a component, in particular for fastening a threaded bolt in a rotor blade of a wind turbine.

[0002] The invention also relates to a tool and a method for assembling the insert. The insert is inserted into a prefabricated hole in a component and bonded to the component. The tool enables position-independent assembly.

[0003] The invention can be applied in all fields of technology in which components are connected to one another. It can primarily be used when components of different stiffnesses need to be securely connected to one another. This applies, among other things, to the connection of fiber composite components or mineral components with metal components.

[0004] The invention can be applied in particular in the field of wind turbines. A rotor blade is often made of glass-fiber-reinforced composite materials, usually epoxy resin with embedded glass fibers (GRP). Carbon-fiber-reinforced plastic (CFRP) is also sometimes used. Because the hybrid materials can be particularly well adapted to specific requirements thanks to the material mix, they have been used increasingly frequently in recent years. However, due to the special nature of the composite material, securely and permanently attaching the rotor blade to a wind turbine hub presents particular challenges.For this purpose, a plurality of generally evenly spaced threaded bolts are arranged in a circle as an insert on the rotor blade root, which are fastened, in particular glued, in recesses of the rotor blade extending essentially to the longitudinal axis of the rotor blade and which serve to connect the rotor blade to a rotor hub of a wind turbine. STAND DER TECHNIK

[0005] Inserts used in components include rotor blades of wind turbines. They are described in detail in patents US 4420354 and US 4915590. A threaded bolt and an insert transfer the forces between two components, for example, between a rotor blade root of a wind turbine rotor blade and a hub of the wind turbine.

[0006] The insert can be assembled by vacuum infusion, as described in patent WO 002012172132. According to the state of the art, an inlet for the adhesive is used at one point on the insert and an outlet for the air in the adhesive gap is used at another point on the insert.

[0007] A weakness of the assembly described above is that air pockets can remain in the gap between the insert and the bore. These air pockets lead to a reduction in the strength of the connection.

[0008] In addition, the position of the component must be precisely maintained during assembly to reduce air inclusions.

[0009] Furthermore, a disadvantageous weak point in the state-of-the-art technology for this type of connection is the area at the front of the insert. Stress peaks form in this area due to the stiffness differences between the insert, adhesive, and component. Under extreme or alternating loads, these stress peaks initially lead to cracks and later to component failure. As a solution to this, the insert's end section has been designed to be very pointed, as shown in patent DE 602004008070. However, this disadvantageously results in a longer component length and correspondingly higher weight and costs.

[0010] WO 2017 / 101944 A1 shows a connecting joint for attaching a wind turbine blade to a rotor hub.

[0011] US 2010 / 0209651 A1 shows a method for producing a connecting structure by vacuum-assisted transfer molding.

[0012] EP 2 138 716 A1 describes a blade insert coupled into a rigid laminate of a rotor blade of a wind turbine. The blade insert comprises a blade insert body configured as an insert, which is bonded to the laminate by a strong, double-receiving connection using an adhesive. For this purpose, the insert has a tapered hollow cone on its end face, and the hole in the rotor blade has a complementary-shaped receptacle. A decoupling element is incorporated into the hollow cone of the insert and into the laminate. The decoupling element can be made of a material with low rigidity. As a result, axial force transmission between the insert and the laminate can only be dissipated via an outer side of the insert.

[0013] EP 2 728 171 A2 shows an arrangement for attaching an insert to a rotor blade. The insert can be attached to an inner wall of the rotor blade using an adhesive. A decoupling element can be inserted at a tip of the adhesive to reduce stress.

[0014] US 2017 / 0050372 A1 discloses a spacer clamp for mounting an insert in a base part. The spacer clamp provides a buffer between surfaces and a first end of the insert. The spacer clamp ensures that the adhesive forces between the insert and the base part can be maintained in all directions.

[0015] WO 2012 / 172132 A1 describes a spray anchor used to create a uniform connection between two parts. However, the spray anchor does not create a mechanical coupling between the two parts, but rather serves only to ensure a homogeneous distribution of the adhesive.

[0016] The object of the present invention is therefore to propose a fastening arrangement, a fastening method and a tool which can be used therefor, which overcome the aforementioned disadvantages.

[0017] This object is achieved by a fastening arrangement, a fastening method, and a fastening tool according to the independent claims. Advantageous embodiments of the invention are the subject of the dependent claims. OFFENBARUNG DER ERFINDUNG

[0018] According to the invention, an arrangement for fastening a component by means of an insert is proposed, wherein the component has at least one hole in a fastening-side end face which is designed to receive the insert, which is inserted into the hole with a front side first, wherein an intermediate space between the insert 21 and the inner wall of the hole is at least partially filled with an adhesive 31, wherein at least one decoupling element is inserted between the insert and the inner wall to reduce stress peaks, the rigidity of which decoupling element is lower than a rigidity of the cured adhesive.

[0019] According to the invention, the hole in the component has a longitudinal axis, wherein the longitudinal axis runs through the geometric center of gravity of the hole, and parts of the decoupling element have a distance from the longitudinal axis which is greater than the arithmetically mean outer radius of the front third of the insert, so that the decoupling element shields a front side of the insert and deflected forces are introduced into the insert at other points.

[0020] The decoupling element enables improved fastening quality, which works synergistically together, but also offers a significant improvement in fastening quality as a standalone measure. Both elements can therefore be used both in combination and individually.

[0021] The invention thus relates, in one aspect, to connections that are screwed together using an insert and bolt and are constructed, for example, as follows: A component is attached to a bracket. The fastening consists of a bolt, a nut, and an insert. The insert is located in a hole in a component and is glued to the component. The insert is screwed to the bolt. The bolt is located in a through-hole in the bracket. A nut on the bolt clamps the entire connection.

[0022] The invention relates to the bonding of the insert to the component. A decoupling element is located in the front area of the insert. The decoupling element reduces the forces acting on the front of the insert. The forces are thus introduced into the insert at a location subject to lower loads.

[0023] The decoupling element reduces the stresses in the connection arrangement, thereby increasing its strength and fatigue strength.

[0024] Different designs of the decoupling element enable the properties described above. For example, the decoupling element can be made of a relatively soft material, such as rubber or foam. This soft material can absorb comparatively low forces and thus not transmit them to the insert.

[0025] In In an advantageous embodiment, a tool can also be inserted into the assembly in such a way that an air pocket between the insert and the component can be reduced during assembly. The tool enables improved fastening quality, which works synergistically, but also offers a significant increase in fastening quality as a standalone measure. In this respect, both elements can be used both in combination and individually.

[0026] In In an advantageous embodiment, the stiffness of the decoupling element can be at least 20% lower than the average stiffness of the cured adhesive, and / or the hole in the component can have cross-sectional areas that are oriented perpendicular to the longitudinal axis of the hole and the surface of the decoupling element can be larger than 10% of the average cross-sectional area of the hole.

[0027] In In an advantageous embodiment, the lower stiffness of the decoupling element can be achieved by a material with at least 20% lower modulus of elasticity than the cured adhesive, and / or the lower stiffness of the decoupling element can be achieved by a recess in the adhesive, and / or the lower stiffness of the decoupling element can be achieved by a separating layer with reduced adhesion between two areas of the construction, and / or the lower stiffness of the decoupling element can be achieved by provoking cracks between two areas of the construction.

[0028] In an advantageous embodiment, the decoupling element can consist of at least one material, and / or the decoupling element can be one-piece or multi-piece, and / or the decoupling element can be a hollow element, and / or the decoupling element can be a cavity. In this respect, the decoupling element can also be a cavity or hollow body. This also prevents the transmission of force between the front side of the insert and the component.

[0029] In an advantageous embodiment, the insert can have at least one side surface which is at a distance from the component, wherein the fastening region of the insert is the part which is located in the component and the arithmetic mean distance between the side surface and the component in the front tenth of the fastening region of the insert can be greater than 10% of the arithmetic mean radius of the fastening region of the insert.

[0030] Decoupling elements have a similar function, initiating cracks at specific locations or creating a separation plane between two areas of the joint. The decoupling element could, for example, be a release agent locally incorporated into the adhesive. Under load, this separation layer also prevents tensile force from being transmitted.

[0031] In an advantageous embodiment, the component can be a rotor blade for wind turbines.

[0032] In a subordinate aspect, a method for fastening a component by means of an arrangement with an insert and a decoupling element is proposed, comprising the following steps: Providing a component with a hole; providing an insert; providing a decoupling element; inserting the decoupling element into the hole of the component; inserting the insert into the component; applying an adhesive; curing the adhesive.

[0033] In an advantageous embodiment, a tool can be used in such a way that an air inclusion between the insert and the component is reduced during assembly.

[0034] In an advantageous embodiment, a gap can be created between the insert and the inner wall of the hole, which gap is filled with the adhesive, wherein air must be displaced for bonding and the displaced air escapes through at least one outlet in the region of the front half of the hole and through at least one outlet in the region of the component-side half of the hole by means of the tool.

[0035] In an advantageous embodiment of the fastening method, a decoupling element as described above can be used.

[0036] In an advantageous embodiment of the fastening method, the component can be a rotor blade for wind turbines.

[0037] In a further subordinate aspect, a tool for assembling a fastening element is proposed. The tool is used in connections that are screwed together using an insert and bolt and are constructed, for example, as follows: A component is attached to a bracket. The fastening consists of a bolt, a nut, and an insert. The insert is located in a hole in a component and is glued to the component. The insert is screwed to the bolt. The bolt is located in a through-hole in the bracket. A nut on the bolt clamps the entire connection.

[0038] In a further aspect, the invention relates to a tool for producing such a connection arrangement. The tool is inserted with the insert into the hole of the component. This creates a gap between the insert, tool, and component that is filled with a medium such as air.

[0039] Both the decoupling element discussed above and the air inclusion reduction tool increase the fastening quality, especially when fastening two joining partners, at least one of which is made of a composite material such as a wind turbine rotor blade. Both the decoupling element and the tool can be used individually or in combination to synergistically significantly increase the load capacity and durability of the fastening.

[0040] The tool is used to mount the insert onto the component and allows for the removal of air between the insert and the component hole. For this purpose, the insert is placed in a hole in the component. The area between the insert and the component is filled with an adhesive.

[0041] When applying the adhesive, the air contained there must be displaced. This can lead to air pockets. To at least partially prevent these air pockets, the position of the component is currently precisely aligned or air pockets are tolerated at the expense of the strength of the bond.

[0042] The proposed tool is designed to prevent air pockets and enable position-independent assembly. It is proposed that the tool have multiple air outlets distributed across the hole depth. This prevents air pockets from forming. Flow control elements that prevent the flow of adhesive through the outlet channels enable position-independent assembly.

[0043] The tool can be used for bonding inserts where position-independent assembly, higher process reliability or reduced assembly times are required.

[0044] The tool thus has at least two outlets through which the medium can escape when bonding the insert. This prevents air pockets in any installation position. This reduces scrap and avoids rework. At least one outlet is located in the area of the front half of the hole and at least one outlet is located in the area of the component-side half of the hole.

[0045] Various tool designs enable the properties described above. The tool can be a single-piece or multi-piece. Membranes, drain siphons, throttles, or overflow containers can be used to prevent the adhesive from blocking the outlets.

[0046] Additionally, the tool can be used to align or center the insert.

[0047] Thus, in an advantageous embodiment, a flow regulating element can be included, wherein said element includes at least one membrane, and / or at least one drain siphon, and / or at least one throttle and / or at least one and / or at least one air release valve.

[0048] In an advantageous embodiment, the tool can center the insert in the hole, and / or the tool can align the insert in the hole, and / or the tool can align the insert to the component, and / or the tool can align the insert to other inserts

[0049] In an advantageous embodiment, the tool may include a heating element.

[0050] In an advantageous embodiment, the tool can consist of at least one material and / or the tool can be formed in one piece or in several parts.

[0051] In an advantageous embodiment, the tool can be specially designed for a component such as a rotor blade for wind turbines.

[0052] In a further subordinate aspect, a method for fastening a component by means of an insert and a previously described tool is proposed, comprising the following working steps: Providing a component with a hole; providing an insert; providing the tool; inserting the insert 21 into the component; inserting at least a part of the tool into the hole of the component; introducing an adhesive; curing the adhesive.

[0053] In an advantageous development of the method, there may be a gap between the insert and the inner wall of the hole, which gap is filled with a medium, in particular an adhesive, which must be displaced for bonding and the medium to be displaced escapes through at least one outlet in the region of the front half of the hole and through at least one outlet in the region of the component-side half of the hole by means of the tool.

[0054] In an advantageous further development of the fastening method using the tool, the component can be a rotor blade for wind turbines. ZEICHNUNGEN

[0055] Further advantages will become apparent from the accompanying drawing description. The drawings illustrate exemplary embodiments of the invention. The drawing, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations.

[0056] They show: Fig. 1 shows a variant of the connecting arrangement 10. The arrangement 10 connects a component 11 with a holder 18; Fig. 2 represents the current state of the art. An insert 21 is located in a hole Fig. 3 / 13 of a component 11. An adhesive 31 connects the insert 21 to the component 11. In the area of the front Fig. 1 / 23 of the insert 21 cracks occur due to the high load 100; Fig. 3 shows the component 11 with a front side 12 in which there is a hole 13. The hole 13 has a longitudinal axis 15; Fig. 4 is a sectional view of component 11 perpendicular to the longitudinal direction Fig. 3 / 15 of the hole 13. There is a hole 13 in the component 11. This hole has a cross-sectional area 14; Fig. 5 represents a variant embodiment of the connecting arrangement 10, wherein the decoupling element is a separating layer 51 which is introduced into the adhesive 31; Fig. 6 represents a variant of the connecting arrangement 10, wherein the decoupling element is provoked cracks 61 in the component 11; Fig. 7 shows an embodiment of the connection arrangement in detail; Fig. 8 represents a variant of an embodiment 40 of the tool according to the invention; Fig. 9 represents a further embodiment variant 50 of the tool; Fig. 10 represents a section through the component 11 with a hole 13. The component has an end face 12. The hole has a longitudinal axis 15; Fig. 11 represents another embodiment of the tool 40; Fig. 12 shows an embodiment of the connecting arrangement 10. The arrangement 10 connects a component 11 to a holder 18; Fig. 13 represents an embodiment 60 of the tool 40; Fig. 14 represents another embodiment 70 of the tool 40; Fig. 15 represents another embodiment 80 of the tool 40; Fig. 16 represents another embodiment 90 of the tool 40); Fig. 17 shows the process of bonding as an embodiment of the fastening method according to the invention; Fig. 18 shows the bonding process as a further embodiment of the fastening method according to the invention with an inclination of +45° of the connecting arrangement 10; Fig. 19 shows the bonding process as a further embodiment of the fastening method according to the invention with an inclination of the connecting arrangement 10 by -45°.

[0057] In the figures, similar elements are numbered with the same reference numerals. The figures show only examples and are not to be understood as limiting.

[0058] Fig. 1 represents a variant embodiment of the fastening arrangement according to the invention. In a hole of a component 11, there is an insert 21 with a side surface 24, with the front side 23 facing forward. A decoupling element 41 is located on the front side 23 of the insert 21. The area between the component 11, the insert 21, and the decoupling element 41 is at least partially filled with cured adhesive 31. A holder 18 rests on the back side 22 of the insert 21. In the holder 18 there is a through hole for a threaded bolt 16. The threaded bolt 16 is screwed to the insert 21. A preload force is applied to the connection 10 via a nut 17.

[0059] In a hole Fig. 3 / 13of the component 11 there is a decoupling element 41 and an insert 21 with at least one side surface 24. The insert 21 is located with the front side 23 facing forward in the component 11. The decoupling element 41 is located in the region of the front side 23 of the insert 21. Adhesive 31 connects insert 21, component 11 and decoupling element 41. The insert 21 is connected to the bolt 16 via a screw connection. The bolt 16 is located in a through hole in the holder 18. The holder 18 rests on the back side 22 of the insert 21. A preload force is applied to the connection 10 via a nut 17.

[0060] In this embodiment, the decoupling element 41 consists of a material that has significantly lower rigidity than that of the cured adhesive 31. Due to the lower rigidity of the decoupling element 41, it can hardly transmit forces between component 11 and the front side 23 of the insert 21. The decoupling element 41 shields the front side 23 of the insert 21. The high stresses on the front side 23 of the insert 21 are reduced. The redirected forces are introduced into the insert 21 at other points due to the decoupling element 41. In this way, the forces are distributed more evenly across the side surface 24 of the insert 21.

[0061] Several versions of the insert 21 are possible. For example, the insert 21 can be Fig. 1 shown, have an internal thread. The internal thread serves to accommodate a bolt 16.

[0062] Another design variant is an insert 21 with an external thread. A nut 17 can be screwed directly onto this insert 21. A bolt 16 is omitted.

[0063] Another variant of an insert 21 is a rod without a thread. The rod is, for example, glued to the bracket 18 or connected to the bracket 18 by a cross bolt or a cotter pin.

[0064] In Fig. 1 The decoupling element 41 protrudes beyond the front side 23 of the insert 21 and partially encloses the side surface 24 of the insert 21. Furthermore, the decoupling element 41 fills a large part of the hole cross-section 14. Both properties independently lead to better decoupling of the insert 21 from the component 11.

[0065] The decoupling element 41 can also be a cavity or hollow body. The hollow body contains, but is not limited to, a gas such as air, a liquid, or a vacuum. The hollow body results in the decoupling element 41 no longer having any rigidity. This arrangement 10 also reduces the forces that can be transmitted in the direction of the longitudinal axis 15 via the shortest path from the component 11 to the insert 21. These forces are directed around the decoupling element 41 and introduced into the insert 21 at another location. This reduces the stress peaks on the front side 23 of the insert 21 and increases the strength of the connection 10.

[0066] The decoupling element 41 can be made of one or more parts. Furthermore, the decoupling element 41 can be made of one or more materials.

[0067] The Fig. 1 The illustrated insert 21 and the hole 13 in the component 11 can be shaped in a variety of ways. Their cross-sections can be round or square, for example. Their cross-sections can vary in length as desired. For example, the insert 21 can taper towards the front side 23 in a blunt, rounded, or pointed manner. For the purposes of description, this patent refers to the diameter of the insert 21 or the diameter of the hole. Fig. 3 / 13 in component 11. If the insert or the hole Fig. 3 / 12 in the component is not round, the diameter of the non-round cross-section Fig. 4 / 14 the diameter of a reference circle Fig. 4 / 81, whose area corresponds to the area of the non-circular cross-section Fig. 4 / 14 The centroids Fig. 4 / 82 of the reference circle and the non-circular cross-section Fig. 4 / 14are identical. For non-circular cross-sections, the insert 21 may also have multiple side surfaces 24.

[0068] Fig. 2 represents a connection arrangement 10 according to the prior art. It consists of a component 11 and an insert 21. The insert 21 is located in a hole Fig. 3 / 13 of component 11. Component 11 and insert 21 are connected with an adhesive 31.

[0069] Due to the voltage peaks on the front Fig. 1 / 23 of the insert 21, cracks 100 occur, which can lead to failure of the connection 10.

[0070] Fig. 3 represents a section through the component 11 with a hole 13. The component has a front side 12. The hole has a longitudinal axis 15. The hole 13 can be made at any angle in the component 11. In Fig. 3 the hole 13 is made perpendicular to the front side 12.

[0071] Fig. 4 is a sectional view of component 11 from Fig. 3 . In this view the hole is Fig. 3 / 13 with its cross-section 14. The cross-section 14 can have any shape. A reference circle 81 has the same area as the cross-section 14 of the hole 13. The centroid 82 of the cross-section 14 and the reference circle 81 are identical.

[0072] Fig. 5 represents a further embodiment of the invention. In the hole Fig. 3 / 13 of component 11 is the insert 21. Component 11 and insert 21 are at least partially connected with adhesive 31. The decoupling element Fig. 1 / 41 is a separating layer 51. This separating layer 51 reduces or prevents the transmission of forces in the direction of the longitudinal axis 15 of the connection 10. The separating layer 51 can be, including but not exclusively, a film or a release agent. The forces are directed around the separating layer 51 and introduced into the insert 21 at a different location.

[0073] This reduces the stress peaks on the front side 23 of the insert 21 and increases the strength of the connection 10.

[0074] Fig. 6 represents a further embodiment of the invention. In the hole Fig. 3 / 13 of component 11 is the insert 21. Component 11 and insert 21 are at least partially connected with adhesive 31. The decoupling element Fig. 1 / 41 are provoked cracks 61 in the adhesive 31, the component 11 or the insert 21. These cracks 61 reduce or prevent the force transmission, among other things, in the direction of the longitudinal axis 15 of the hole Fig. 3 / 13 . The cracks 61 may be caused including but not limited to notches in the adhesive 31, notches on the inside of the hole Fig. 3 / 13 or notches on insert 21.

[0075] In Fig. 7 The connection arrangement 10 is shown in detail. The hole 13 in the component 11 has a geometric center of gravity 71. A part of the decoupling element 41 is at a distance 72 from the longitudinal axis 15 of the hole 13. The insert 21 has an outer radius 73. The component 11 is at a distance 74 from the side surface 24 of the insert 21.

[0076] The connection arrangement 10 is manufactured, for example, by drilling a hole 13 into a component 11. A decoupling element 41 is then inserted into the component. In a further step, an insert 21 is inserted into the hole with the front side 23 facing forward. The resulting space between component 11, insert 21, and decoupling element 41 is filled with adhesive 31. The space can be filled, for example, by vacuum infusion or injection. It would also be possible to first introduce the adhesive 31 into the hole 13 of the component 11 and then press the decoupling element 41 and the insert 21 into the still liquid adhesive 31. In a further step, the adhesive 31 hardens and is tempered if necessary. Finally, the insert 21 can be fastened to a holder 18 using a bolt 16 and a nut 17.

[0077] A variant of the production of the connecting arrangement 10 described above is to apply the adhesive 31 in two layers. The hole 13 in the component 11 is filled with a first layer of adhesive 31 up to just before the front side 23 of the insert 21. The first layer of the adhesive 31 then cures. In a second step, the insert 21 is inserted into the hole 13 of the component 11. The remaining space between the insert 21 and the component 11 is then filled with a second layer of adhesive 31. The second layer of the adhesive 31 then cures. In the transition area between the first and second layers of adhesive 31, the adhesion is greatly reduced. In this case, the transition area with reduced adhesion is the decoupling element 41. Under low loads, cracks 61 develop in the contact surface between the adhesive layers. Forces cannot be transmitted or can only be transmitted to a limited extent in the transition area.are only transmitted to a reduced extent and the voltage increases in the area of the front side 23 of the insert 21 are reduced.

[0078] A variant of the above-described production of the connecting assembly 10 is the application of a release agent to the bottom of the borehole or to a first layer of adhesive. The surface 51 coated with the release agent cannot transmit forces and shields the front side 23 of the insert 21 from forces.

[0079] The aim of the further proposed assembly tool 40, 50, 60, 70, 80, 90 is to make the connecting assembly 10 simpler and more reliable. The connecting assembly 10 in question contains an insert 21 that is bonded to a component 11. A tool 40 is to be used for the assembly of the inserts 21. The tool 40 is to reliably remove the air between the insert 21 and the component 11. Furthermore, the tool 40 is to align the insert 21 in the hole 13 of the component 11.

[0080] To reliably remove the air, the tool 40 should have at least two air outlets. At least one outlet 49 should be located in the front area of the hole 13. At least a second outlet 42 should be located in the component-side area of the hole 13. As long as at least one of the outlets 49, 42 is not blocked with adhesive 31 during the introduction of the adhesive 31, air can continue to be removed from the gap 31 between the insert 21 and the component 11. This leads to fewer air pockets and thus to greater process reliability during the assembly of the insert 21.

[0081] Fig. 8 represents a version of the tool 40. Insert 21 and tool 40 are partially located in the hole 13 of the component 11. This creates a gap 31 between tool 40, component 11 and insert 21, which is filled with a medium such as air. Before component 11 is glued to insert 21, the medium must be displaced from the gap 31. A gap 31 between component 11, insert 21 and tool 40 is filled with air. To glue insert 21 to component 11, the gap 31 must be filled with adhesive. For this to happen, the air in the gap 31 must escape. For this purpose, tool 40 has air outlets 49, 42. After component 11 and insert 21 have been glued, tool 40 is removed so that only insert 21 remains in component 11.

[0082] Fig. 9 shows details of the variant of tool 40 from Fig. 8 . The tool 40 has a first outlet 49 and a second outlet 42 for the medium to be displaced. The medium is guided through a channel 46 and discharged at a drain nozzle 44. The adhesive is fed to the tool 40 at the inlet nozzle 45. The adhesive is passed through a channel 47 in the tool and introduced at the inlet 43 into the area 31 between component 11 and insert 2). The tool 40 has two outlets 49, 42. One of the outlets 49 is located in the front area of the hole 13. The second outlet 42 is located in the component-side area of the hole 13. The outlets 49, 42 are connected to the drain nozzle 44 via a drain pipe 46. The outlets 49, 42, the drain pipe 46 and the drain nozzle 44 serve to drain the air from the space 31 between insert 21, component 11 and tool 40. In addition, the tool 40 has an inlet nozzle 45 which is connected to the inlet 43 via an inlet pipe 47.The adhesive is introduced into the intermediate space 31 via inlet nozzle 45, inlet pipe 47 and inlet 43.

[0083] The adhesive can be introduced into the gap 31 in various ways. One variant is the introduction of the adhesive by vacuum infusion. A negative pressure is applied to the outlet nozzle 44. This largely sucks out the air contained in the gap 31. The adhesive is then introduced into the gap 31 via the inlet nozzle 45. The remaining air in the gap 31 can be sucked out via the outlets 49, 42 until both outlets 49, 42 are blocked with adhesive.

[0084] Another variant is to press the adhesive into the gap 31 via the inlet nozzle 45. During the pressing process, the air is displaced by the adhesive 31. The air can escape through the two outlets 49, 42. Only when both outlets 49, 42 are blocked with adhesive can the air no longer escape. With this variant, the tool 40 must be fixed to the component 11, since the excess pressure in the gap 31 would otherwise force the tool out of the hole 13.

[0085] Fig. 10 represents a section through the component 11 with a hole 13. The component has a front side 12. The hole has a longitudinal axis 15. The hole 13 can be made at any angle in the component 11. In Fig. 10 the hole 13 is made perpendicular to the front side 12.

[0086] Fig. 11 represents a variant embodiment 50 of the tool 40. In this variant, the tool 50 consists of two parts. The tool consists of a first part 53 and a second part 52. The first part 53 is located in the area of the rear side 22 of the insert 21. The second part 52 is located in the area of the front side 23 of the insert 21. A first outlet of the tool 40 is located on the first part 53, a second outlet on the second part 52. Thus, the front part of the tool 53 comprises an inlet 43 and the first outlet 49. The component-side part of the tool 52 comprises the second outlet 42. In this variant, the insert 21 replaces part of the drain pipe 46. In this variant, after the insert 21 has been glued to the component 11, only the first part 53 of the tool 40 is removed from the connecting arrangement 10. The second part 52 of the tool 40 remains in the connecting arrangement 10.In this version, the Insert 21 takes care of the return of the medium.

[0087] Fig. 12 represents a variant of a fully assembled connection arrangement 10. In a hole, see Fig. 10 / 19 , of the component 11 there is an insert 21 with at least one side surface 24. The insert 21 is located with the front side 23 facing in the component 11. Adhesive 31 connects insert 21 and component 11 to each other. A part of the tool 40 can be inserted into the hole after gluing, see Fig. 10 / 19of the component 11 remain. The insert 21 is connected to the bolt 16 via a screw connection. The bolt 16 is located in a through hole in the holder 18. The holder 18 rests on the back 22 of the insert 21. A preload force is applied to the connection 10 via a nut 17. The insert 21 is located with its front side 23 first in a hole 13 of a component 11. On the front side 23 of the insert 21 is part of the tool 40 which is used for assembly. The space 31 between component 11 and side surface 24 of the insert 21 is filled with cured adhesive. The part of the tool 40 on the back 22 of the insert 21 has been removed. A holder 18 rests on the back 22 of the insert 21. In the bracket 18 there is a through hole for a threaded bolt 16. The threaded bolt 16 is screwed to the insert 21.A preload force is applied to the connection 10 via a nut 17.

[0088] In the embodiments described so far, the outlets clog each other during bonding. For example, as soon as adhesive reaches the first outlet 49, the adhesive is passed through the drain pipe 46 toward the drain connection 44. As soon as the adhesive reaches the pipe branch 48, the adhesive clogs the second outlet 42. The air remaining in the gap 31 cannot be displaced any further.

[0089] The following describes design variants that prevent the outlets from clogging each other. These variants include a flow control element 62. The flow control element 62 allows air to escape. The flow rate of the adhesive is slowed or stopped by the flow control element 62.

[0090] Fig. 13 represents a variant embodiment 60 of the tool 40. A flow control element 62 is located in the outlet pipe 46. In this variant, the flow control element 62 is a membrane. Air can escape through this membrane, and adhesive is retained by it. The tool thus contains a membrane 62 through which the medium can escape. However, the adhesive 31 cannot penetrate the membrane 62. This variant ensures that the channel at the outlet 49 is not closed by the adhesive, which is discharged through the second outlet 42. If a membrane 62 is provided at both outlets, this enables position-independent assembly of the insert. Adhesive that is sucked out through the component-side outlet 42 is thus retained by the membrane. The adhesive cannot reach the pipe branch 48. Thus, the adhesive cannot clog the first outlet 49.If an additional membrane is provided between the first outlet 49 and the pipe branch 48, mutual clogging of the outlets is excluded.

[0091] Fig. 14 represents a variant 70 of the tool 40 with a flow control element 76. In this variant, the flow control element 76 is a drain siphon. The siphon between the first outlet 49 and the pipe branch 48 is located at the level of the second outlet 42. This retains the adhesive 31 from the pipe branch until the adhesive reaches the second outlet 42. The tool thus includes a drain siphon 76. If a drain siphon is provided at both outlets, this enables position-independent installation of the insert.

[0092] Fig. 15 represents a variant 80 of the tool with a flow control element 81. In this variant, the flow control element 81 is a throttle. The throttle reduces the flow rate of the adhesive. The adhesive reaches the pipe branch 48 with a significant delay. The air remaining in the intermediate space 31 can thus be extracted for a significantly longer time. In this respect, the tool 80 includes a throttle 81. The throttle can include, but is not limited to, a reduction in the cross-sectional area in the channel 46. If a throttle is provided at both outlets, this enables at least temporary position-independent assembly of the insert.

[0093] Fig. 16 represents a variant 90 of the tool 40 with a flow control element 91. In this variant, the flow control element 91 is an overflow container. The adhesive must first fill the overflow container before it reaches the pipe branch 48. The air remaining in the gap 31 can thus escape for a significantly longer time. The tool thus includes an overflow container 91. If an overflow container is provided at both outlets, this enables at least temporary, position-independent assembly of the insert.

[0094] Another variant of a flow control element is an air release valve. The mechanism of the air release valve allows air to escape but prevents the flow of adhesive.

[0095] Fig. 17 represents the end of the bonding process. The gap 31 between insert 21 and component 11 is almost completely filled with adhesive. A closure 101 has formed in the central area of hole 13. The adhesive divides the remaining gap 31 into two parts 102, 103. However, thanks to the two suction devices, the air remaining in the gaps 102, 103 can still escape. In this way, the gap 31 can be completely filled with adhesive. Adhesive is thus introduced into the area between insert 21 and component 11 through the inlet 49 in the tool 40. At the top of hole 13, the adhesive 31 forms a closure 101. In this way, two air pockets 102 and 103 are created. Both air pockets can be further filled with adhesive because the air they contain can escape through the two outlets of the tool 40.

[0096] Fig. 18 und 19 represent the possibility of position-independent assembly by the invention. In Fig. 18 The front side 12 of component 11 is tilted downward. In this position, the front outlet 49 becomes blocked at the beginning of the bonding process. However, the air can reliably escape through the component-side outlet 42 until the gap 31 is completely filled with adhesive. The rear outlet opening allows the area between insert 21 and component 11 to be completely filled with adhesive 110.

[0097] In Fig. 19 The front side 12 of the component 11 is tilted upward. In this position, the component-side outlet 42 becomes blocked at the beginning of the bonding process. However, the air can reliably escape through the front outlet 49 until the gap 31 is completely filled with adhesive. The tool 40 enables the area between the insert 21 and the component 11 to be completely filled with adhesive 120.

[0098] Fig. 18 und 19 show that the tool 40 allows for position-independent assembly of the connection arrangement 10. It should be noted that in the outlet channels the devices made of Fig. 6 bis Fig. 9 are to be provided.

[0099] Another variant of the tool 40 serves not only for venting but also for centering or aligning the insert 21 in the component 11. This allows, for example, the distance between the insert 21 and the inner wall of the bore 13 to be precisely adjusted. Furthermore, the position between several inserts 21 arranged next to one another can be determined. This can be used to produce a planar connecting flange from a plurality of inserts.

[0100] Another variant of the tool 40 serves not only for venting but also for heating the connection arrangement 10. A heating element in the tool 40 heats the connection arrangement 10. This enables a defined temperature control of the adhesive during application, faster curing, and tempering of the connection arrangement 10. Bezugszeichenliste

[0101] 10Fastening device 11Component 12Front half of the hole 13Hole of the component 14Cross-sectional areas of the hole of the component 15Longitudinal axis of the hole 16Bolt 17Nut 18Bracket 21Insert 22Back of the insert 23Front of the insert 24Side surface of the insert 31Adhesive 40Tool 41Decoupling element 42Air inlet / air outlet 43Inlet area between insert and component 44Drain nozzle of the tool 45Inlet nozzle of the tool 46Channel in the tool / drain pipe 47Channel in the tool / inlet pipe 48Pipe branch 49Air inlet / air outlet 50Tool 51Separating layer of the decoupling element 52Component-side part / second part of the tool 53Front-side part / first Part of the tool 60Tool 61Cracks between two areas of the structure 62Flow regulation element / membrane 70Tool 71Geometric center of gravity of the hole 72Distance of the decoupling element from the longitudinal axis 73Outer radius of the insert 74Distance of the side surface of the insert from the component75Insert mounting area 76Flow regulator / tool drain siphon 80Tool 81Flow regulator / tool throttle 90Tool 91Flow regulator / tool overflow container 101Adhesive seal 102Air pockets 103Air pockets 110Adhesive 120Adhesive

Claims

1. Arrangement (10) for fastening a component (11) by means of an insert (21), in particular for fastening a threaded bolt inside a rotor blade of a wind turbine, whereby the arrangement (10) comprises at least the component (11), the insert (21), an adhesive (31) and at least one decoupling element (41), said component (11) having in an end face (12) on the fastening side at least one hole (13) designed to receive the insert (21), which is inserted into the hole (13) with a front face (23) first, an intermediate space between the insert (21) and the inner wall of the hole (13) being at least partially filled with the adhesive (31), whereby the decoupling element (41) for reducing stress peaks is inserted between the insert (21) and the inner wall whose stiffness is less than a stiffness of the cured adhesive (31), characterized in that the hole (13) in the component (11) has a longitudinal axis (15), said longitudinal axis (15) passes through the geometrical centre (71) of the hole (13), and parts of the decoupling element (41) have a distance (72) to the longitudinal axis (15) which is greater than the arithmetical mean outer radius (73) of the front third of the insert (21), so that the decoupling element (41) shields one front side (23) of the insert (21) and deflected forces are introduced into the insert (21) at other points.

2. Arrangement according to claim 1, characterized in that a tool (40, 50, 60, 70, 80, 90) is inserted in the arrangement (10) in such a way that during air entrapment between the insert (21) and the component (11) can be reduced during assembly.

3. Arrangement according to claim 1 or 2, characterized in that the stiffness of the decoupling element (41) is at least 20% less than the average stiffness of the cured adhesive (31), and / or the hole (13) in the component (11) has cross-sectional surfaces (14) aligned vertical to the longitudinal axis (15) of the hole (13) and the surface of the decoupling element (41) is larger than 10% of the average cross-sectional surface (14) of the hole (13).

4. Arrangement according to one of the previous claims, characterized in that the lower stiffness of the decoupling element (41) is attained by a material with a modulus of elasticity at least 20% lower than the cured adhesive (31), and / or the lower stiffness of the decoupling element (41) is attained by an omission in the adhesive (31), and / or the lower stiffness of the decoupling element (41) is attained by a separating layer (51) with reduced adhesion between two areas of the construction, and / or the lower stiffness of the decoupling element (41) is attained by the provocation of cracks (61) between two areas of the construction.

5. Arrangement according to one of the previous claims, characterized in that the decoupling element (41) consists of at least one material, and / or the decoupling element (41) is one-part or multi-part, and / or the decoupling element (41) is a hollow element, and / or the decoupling element (41) is a hollow space.

6. Arrangement according to one of the previous claims, characterized in that the insert (21) has at least one side face (24) having a distance (74) from the component (11), and the fastening area (75) of the insert (21) is that part which is located in the component (11), and the arithmetical mean distance (74) between the side face (24) and the component (11) in the front tenth of the fastening area (75) of the insert (21) is greater than 10% of the arithmetical mean radius (73) of the fastening area (75) of the insert (21).

7. Arrangement according to one of the preceding claims, characterized in that the component (11) is a rotor blade for wind turbines.

8. Method for fastening a component (11) by means of an arrangement with an insert (21) and a decoupling element (41) according to one of the preceding claims, with the work steps: - Provision of the component (11) with hole (13); - Provision of the insert (21); - Provision of the decoupling element (41); - Insertion of the decoupling element (41) into the hole (13) of the component (11); - Insertion of the insert (21) into the component (11); - Emplacing of an adhesive (31); - Curing of the adhesive (31).

9. Method according to claim 8, characterized in that a tool (40, 50, 60, 70, 80, 90) is used in such a way that air entrapment between the insert (21) and the component (11) is reduced during assembly.

10. Method according to claim 9, characterized in that an intermediate space is created between the insert (21) and the inner wall of the hole (13) which is filled with an adhesive (31) whereby air must be displaced for bonding, and the displaced air escapes through at least one outlet in the area of that half of the hole (13) on the end face side (12) and through at least one outlet in the area of that half of the hole (13) on the component side by means of the tool (40, 50, 60, 70, 80, 90).

11. Arrangement according to one of claims 8 to 10, characterized in that the component (11) is a rotor blade for wind turbines.

12. Set, comprising an arrangement according to claim 2 and a tool (40, 50, 60, 70, 80, 90), whereby said tool (40, 50, 60, 70, 80, 90) has at least two outlets (49, 42) for the air to be displaced during the insertion of the adhesive (31), where at least one first outlet (49) can be assigned to an area of that half of the hole (13) on the end face side (12) and at least one second outlet (42) can be assigned to an area of that half of the hole (13) on the component side, characterized in that said tool (40, 50, 60, 70, 80, 90) contains at least one flow regulation element (62, 76, 81, 91), whereby the flow regulation element (60) contains at least one membrane (62), and / or at least one discharge siphon (76), and / or a restrictor (81), and / or an overflow container (91) and / or an air outflow valve.

13. Set according to claim 12, characterized in that the tool centres the insert (21) in the hole (13), and / or the tool (40, 50, 60, 70, 80, 90) aligns the insert (21) in the hole (13), and / or the tool (40, 50, 60, 70, 80, 90) aligns the insert (21) to the component (13), and / or the tool (40, 50, 60, 70, 80, 90) aligns the insert (21) to other inserts.

14. Set according to one of the previous claims 12 to 13, characterized in that the tool (40, 50, 60, 70, 80, 90) contains a heating element.

15. Set according to one of the previous claims 12 to 14, characterized in that the tool (40, 50, 60, 70, 80, 90) consists of at least one material, and / or the tool (40, 50, 60, 70, 80, 90) is one-part or multi-part.

16. Set according to one of the previous claims 12 to 15, characterized in that the component (11) is a rotor blade for wind turbines.