ASSEMBLY, METHOD, AND TOOL FOR SECURING COMPONENTS
20220195982 · 2022-06-23
Inventors
Cpc classification
B29C66/7212
PERFORMING OPERATIONS; TRANSPORTING
F03D1/0675
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B29C66/71
PERFORMING OPERATIONS; TRANSPORTING
B29C66/71
PERFORMING OPERATIONS; TRANSPORTING
B29C66/53
PERFORMING OPERATIONS; TRANSPORTING
B29C66/7212
PERFORMING OPERATIONS; TRANSPORTING
Y02E10/72
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
F05B2230/60
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F03D1/0658
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F03D80/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B29K2063/00
PERFORMING OPERATIONS; TRANSPORTING
B29K2063/00
PERFORMING OPERATIONS; TRANSPORTING
F05B2260/301
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
Abstract
Components are fastened with inserts that are placed into a hole in the component and bonded with an adhesive. A decoupling element is provided on the front face of the insert. This diverts the forces around the highly stressed front face of the inserts. The insert may be of a material with a lower stiffness compared with the adhesive. This arrangement may reduce stress peaks and increase the load capacity of the connection. A tool may be provided that reduces air inclusion between the insert and the component during fitting. The connection arrangement can be used when components of different stiffnesses have to be securely connected to one another. This applies to, among other things, fastening of fibre composite components or mineral components to metal components.
Claims
1. An arrangement for fastening a component by means of an insert, in particular for fastening a threaded bolt inside a rotor blade of a wind turbine, said component having in an end face on the fastening side at least one hole designed to receive the insert, which is inserted into the hole with a front face first, an intermediate space between the insert and the inner wall of the hole being at least partially filled with an adhesive, wherein at least one decoupling element for reducing stress peaks is inserted between the insert and the inner wall whose stiffness is less than a stiffness of the cured adhesive and/or a tool is inserted which reduces air inclusion between insert and component during fitting.
2. The arrangement according to claim 1, wherein the hole in the component has a longitudinal axis, said longitudinal axis passes through the geometrical centre of the hole, and parts of the decoupling element have a distance to the longitudinal axis which is greater than the arithmetical mean outer radius of the front third of the insert.
3. The arrangement according to claim 1, wherein the stiffness of the decoupling element is at least 20% less than the average stiffness of the cured adhesive, and/or the hole in the component has cross-sectional surfaces aligned vertical to the longitudinal axis of the hole and the surface of the decoupling element is larger than 10% of the average cross-sectional surface of the hole.
4. The arrangement according to claim 1, wherein the lower stiffness of the decoupling element is attained by a material with a modulus of elasticity at least 20% lower than the cured adhesive, and/or the lower stiffness of the decoupling element is attained by an omission in the adhesive, and/or the lower stiffness of the decoupling element is attained by a separating layer with reduced adhesion between two areas of the construction, and/or the lower stiffness of the decoupling element is attained by the provocation of cracks between two areas of the construction.
5. The arrangement according to claim 1, wherein the decoupling element consists of at least one material, and/or the decoupling element is one-part or multi-part, and/or the decoupling element is a hollow element, and/or the decoupling element is a hollow space.
6. The arrangement according to claim 1, wherein the insert has at least one side face having a distance from the component, and the fastening area of the insert is that part which is located in the component, and the arithmetical mean distance between the side face and the component in the front tenth of the fastening area of the insert is greater than 10% of the arithmetical mean radius of the fastening area of the insert.
7. The arrangement according to claim 1, wherein the component is a rotor blade for wind turbines.
8. A method for fastening a component by means of an insert, with the work steps: Provision of a component with hole; Provision of an insert; Provision of a decoupling element; Insertion of the decoupling element into the hole of the component; Insertion of the insert into the component; Emplacing of an adhesive; Curing of the adhesive.
9. The method according to claim 8, wherein a decoupling element is used.
10. The method according to claim 8, wherein the component is a rotor blade for wind turbines.
11. A tool having at least two outlets for a medium to be displaced, where at least one outlet is in the area of that half of the hole on the end face side and at least one outlet is in the area of that half of the hole on the component side.
12. The tool according to claim 11, wherein said tool contains at least one flow regulation element, and/or the tool contains at least one membrane, and/or the tool contains at least one discharge siphon and/or the tool contains at least one restrictor, and/or the tool contains at least one overflow container, and/or the tool contains at least one air outflow valve.
13. The tool according to claim 11, wherein the tool centres the insert in the hole, and/or the tool aligns the insert in the hole, and/or the tool aligns the insert to the component, and/or the tool aligns the insert to other inserts.
14. The tool according to claim 11, wherein the tool contains a heating element.
15. The tool according to claim 11, wherein the tool consists of at least one material, and/or the tool is one-part or multi-part.
16. The tool according to claim 11, wherein the component is a rotor blade for wind turbines.
17-19. (canceled)
Description
DETAILED DESCRIPTION OF THE DRAWINGS
[0065] Further advantages emerge from the following drawing description. The drawing shows examples of the invention. The drawing, the description and the claims contain many features in combination. The person skilled in the art will also consider the features individually, and combine them into useful further combinations.
[0066] In the drawing,
[0067]
[0068]
[0069]
[0070]
[0071]
[0072]
[0073]
[0074]
[0075]
[0076]
[0077]
[0078]
[0079]
[0080]
[0081]
[0082]
[0083]
[0084]
[0085]
DETAILED DESCRIPTION OF THE INVENTION
[0086] In the figures, identical or similar components have the same reference numerals. The figures show only examples and must not be understood as restrictive.
[0087]
[0088] A decoupling element 41 and an insert 21 with at least one side face 24 is located in a hole,
[0089] In this design variant, the decoupling element 41 consists of a material having a stiffness considerably lower than that of the cured adhesive 31. Due to the lower stiffness of the decoupling element 41, it can transmit hardly any forces between the component 11 and the front face 23 of the insert 21. The decoupling element 41 shields the front face 23 of the insert 21. The high stresses on the front face 23 of the insert 21 fall. The deflected 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 over the side face 24 of the insert 21.
[0090] Several design variants of the insert 21 are possible. For example, the insert 21 can, as shown in
[0091] 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 not needed.
[0092] A further design variant of an insert 21 is a rod without a thread. The rod is for example bonded to the holder 18 or connected by a cross-bolt or a split pin to the holder 18.
[0093] In
[0094] The decoupling element 41 can also be a hollow space or hollow body. The hollow body contains inclusively, but not exclusively, a gas, for example air, a liquid or a vacuum. The hollow body leads to the decoupling element 41 no longer having any stiffness. This arrangement 10 too reduces the forces that can be transmitted in the direction of the longitudinal axis 15 by the shortest route from the component 11 to the insert 21. These forces are deflected around the decoupling element 41 and introduced into the insert 21 at another point. As a result, the stress peaks on the front face 23 of the insert 21 are reduced and the strength of the connection 10 is increased.
[0095] The decoupling element 41 can be one-part or multi-part. Furthermore, the decoupling element 41 can consist of one or more materials.
[0096] The insert 21 shown in
[0097]
[0098] Due to the excess stresses on the front face,
[0099]
[0100]
[0101]
[0102] As a result, the stress peaks on the front face 23 of the insert 21 are reduced and the strength of the connection 10 is increased.
[0103]
[0104]
[0105] The connection arrangement 10 is made 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 placed with its front face 23 first into the hole. The resultant intermediate space between component 11, insert 21 and decoupling element 41 is filled with adhesive 31. The intermediate space can be filled for example by vacuum infusion or injection. It would also be possible to emplace the adhesive 31 first in the hole 13 of the component 11 and then to press the decoupling element 41 and the insert 21 into the still-liquid adhesive 31. In a further step, the adhesive 31 cures and is if required tempered. Finally, the insert 21 can be fastened with the aid of a bolt 16 and a nut 17 to a holder 18.
[0106] A variant of the manufacture described above of the connection arrangement 10 is to emplace the adhesive 31 in two layers. The hole 13 in the component 11 is filled up to just in front of the front face 23 of the insert 21 with a first layer of adhesive 31. Then the first layer of the adhesive 31 cures. In a second step, the insert 21 is placed into the hole 13 of the component 11. The remaining intermediate space between insert 21 and component 11 is then filled with a second layer of adhesive 31. Then the second layer of the adhesive 31 cures. The adhesion is greatly reduced in the transition area between the first and second layers of adhesive 31. The transition area with reduced adhesion is in this case the decoupling element 41. Under a low load, cracks 61 ensue in the contact surface between the adhesive layers. Forces cannot be transmitted or only to a reduced extent in the transition area, and the excessive stresses in the area of the front face 23 of the insert 21 are reduced.
[0107] A variant of the manufacture described above of the connection arrangement 10 is to apply a separating means to the bottom of the drilled hole or onto a first layer of adhesive. The surface 51 wetted with separating means cannot transmit forces and shields the front face 23 of the insert 21 against forces.
[0108] The aim of the furthermore proposed fitting tool 40, 50, 60, 70, 80, 90 is to design the connection arrangement 10 simpler and more reliable. The connection arrangement 10 referred to contains an insert 21 that is bonded to a component 11. A tool 40 is to be used for fitting the inserts 21. The tool 40 is intended to reliably remove the air between the insert 21 and the component 11. Furthermore, the tool 40 is intended to align the insert 21 in the hole 13 of the component 11.
[0109] For reliable removal of the air, the tool 40 should have at least two air outlets. Of these, at least one outlet 49 should be located in the area of the hole 13 on the end face side. At least one second outlet 42 should be located in the area of the hole 13 on the component side. As long as at least one of the outlets 49, 42 is not blocked with adhesive 31 during emplacing of the adhesive 31, air can still be removed from the intermediate space 31 between the insert 21 and the component 11. This leads to fewer air inclusions and hence to a higher process reliability during fitting of the insert 21.
[0110]
[0111]
[0112] The adhesive can be emplaced in the intermediate space 31 in different ways. One variant is to emplace the adhesive by means of vacuum infusion. A negative pressure is applied at the outflow port 44. The air present in the intermediate space 31 is thus largely extracted. Then the adhesive is emplaced in the intermediate space 31 via the inlet port 45. The rest of the air remaining in the intermediate space 31 can be extracted via the outlets 49, 42 until both outlets 49, 42 are blocked with adhesive.
[0113] A further variant is to press the adhesive into the intermediate space 31 via the inlet port 45. During pressing in, the air is displaced by the adhesive 31. The air can escape through the two outlets 49, 42. Escape of the air is no longer possible only when both outlets 49, 42 are blocked with adhesive. In this variant, the tool 40 must be fixed on the component 11, since the positive pressure in the intermediate space 31 would otherwise press the tool out of the hole 13.
[0114]
[0115]
[0116]
[0117] In the previously described design variants, the outlets block reciprocally during bonding. As soon as adhesive reaches the first outlet 49, for example, the adhesive is passed on through the outflow pipe 46 in the direction of the outflow port 44. As soon as the adhesive has reached the pipe branch 48, the adhesive blocks the second outlet 42. The air remaining in the intermediate space 31 can no longer be displaced.
[0118] The following describes design variants that prevent reciprocal blocking of the outlets. These variants contain a flow regulation element 62. The flow regulation element 62 allows air to escape. The flow velocity of the adhesive is slowed by the flow regulation element 62, or its flow is stopped.
[0119]
[0120]
[0121]
[0122]
[0123] A further variant of a flow regulation element is for example an air outflow valve. The mechanism of the air outflow valve permits the escape of air, but prevents the flow of adhesive.
[0124]
[0125]
[0126] In
[0127]
[0128] A further design variant of the tool 40 is also used for centring or alignment of the insert 21 in the component 11 in addition to air removal. This allows for example the distance between the insert 21 and the inner wall of the hole 13 to be precisely set. Furthermore, it allows the position between several adjacently arranged inserts 21 to be fixed. This can be used to manufacture a planar connecting flange from a plurality of inserts.
[0129] A further design variant of the tool 40 is also used for heating the connection arrangement 10 in addition to air removal. A heating element in the tool 40 heats the connection arrangement 10. This permits defined temperature control of the adhesive during emplacement, faster curing, and tempering of the connection arrangement 10.
REFERENCE NUMERAL LIST
[0130] 10 Fastening device [0131] 11 Component [0132] 12 Half of the hole on the end face side [0133] 13 Hole of component [0134] 14 Cross-sectional surfaces of the hole of the component [0135] 15 Longitudinal axis of hole [0136] 16 Bolt [0137] 17 Nut [0138] 18 Holder [0139] 21 Insert [0140] 22 Rear face of the insert [0141] 23 Front face of the insert [0142] 24 Side face of the insert [0143] 31 Adhesive [0144] 40 Tool [0145] 41 Decoupling element [0146] 42 Air inlet/air outlet [0147] 43 Inlet area between insert and component [0148] 44 Outflow port of the tool [0149] 45 Inlet port of the tool [0150] 46 Duct in the tool/outflow pipe [0151] 47 Duct in the tool/inlet pipe [0152] 48 Pipe branch [0153] 49 Air inlet/air outlet [0154] 50 Tool [0155] 51 Separating layer of the decoupling element [0156] 52 Part on component side/second part of the tool [0157] 53 Part on end face side/first part of the tool [0158] 60 Tool [0159] 61 Cracks between two areas of the construction [0160] 62 Flow regulation element/membrane [0161] 70 Tool [0162] 71 Geometrical centre of gravity of the hole [0163] 72 Distance of the decoupling element to the longitudinal axis [0164] 73 Outer radius of the insert [0165] 74 Distance of the side face of the insert from the component [0166] 75 Fastening area of the insert [0167] 76 Flow regulation element/discharge siphon of the tool [0168] 80 Tool [0169] 81 Flow regulation element/restrictor of tool [0170] 90 Tool [0171] 91 Flow regulation element/overflow container of the tool [0172] 101 Adhesive blockage [0173] 102 Air inclusions [0174] 103 Air inclusions [0175] 110 Adhesive [0176] 120 Adhesive