INSULATION ELEMENT

Description

[0001] The invention relates to an insulating element for insulating a structural element in a motor vehicle.

[0002] Components such as the bodies and / or frames of means of transport and locomotion, particularly waterborne or land-based vehicles or aircraft, often have structures with cavities to enable lightweight construction. However, these cavities cause a variety of problems. Depending on the type of cavity, it must be sealed to prevent the ingress of moisture and contaminants, which can lead to corrosion of the components. It is often also desirable to significantly reinforce the cavities and thus the component, while maintaining a low weight. It is also often necessary to stabilize the cavities and thus the components in order to reduce noise that would otherwise be transmitted along or through the cavity.Many of these cavities are irregular in shape or narrow in size, making them difficult to properly seal, reinforce, and dampen.

[0003] Particularly in automotive engineering, but also in aircraft and boat building, sealing elements (baffles) are used to seal cavities and / or acoustically insulate them, or reinforcing elements (reinforcers) are used to reinforce cavities.

[0004] In Fig. 1 A schematic representation of an automobile body is shown. The body 10 comprises various structures with cavities, such as pillars 14 and supports or struts 12. Such structural elements 12, 14 with cavities are typically sealed or reinforced with sealing and / or reinforcing elements 16.

[0005] US 5766719 discloses a sealing element with a sandwich-like structure. Further insulation elements are known, among others, from JP2000238589A.

[0006] The disadvantage of previously known sealing and / or reinforcement elements is that a custom-fit element must be manufactured for each body shape and each cavity. This leads to high development and manufacturing costs and is particularly disadvantageous for smaller vehicle series.

[0007] It is therefore an object of the present invention to provide an improved insulating element for insulating a structural element in a motor vehicle that avoids the disadvantages of the prior art. The insulating element is intended to offer economic advantages, particularly for small-scale production, and to reduce overall development and manufacturing costs for the insulating elements.

[0008] This object is achieved by an insulating element for insulating a structural element in a motor vehicle, according to claim 1.

[0009] This solution has the advantage of providing an insulating element that ensures very efficient foam filling of cavities. Due to the sandwich-like construction, the expandable material is already directed in a desired direction during expansion. Ribs arranged between the walls further improve this directional effect. Firstly, the ribs channel the expansion in the longitudinal direction of the ribs, i.e. essentially beyond the second edge of the walls, which is desirable because the largest gap between the support and the structural element often has to be overcome in this direction. Furthermore, the ribs ensure that the expandable material can support itself on these two ribs during the expansion process. Depending on the spatial orientation of the insulating element, the expansion can be deflected in an undesired direction by gravity.The ribs ensure the most stable expansion behavior possible in the desired direction, regardless of the spatial orientation of the insulation element.

[0010] A key idea of ​​the present invention is, in particular, that a large number of differently shaped cavities can be insulated using a standardized insulating element. The improved guidance of the expansion process through the walls and the ribs means that the insulating element proposed here can also be used to insulate cavities that have larger gaps between the support and the structural element. For this reason, the insulating element proposed here can be used for structural elements with large gaps as well as for structural elements with small gaps between the support and the structural element. This offers the advantage that the insulating element can be produced in large quantities, which is advantageous with regard to tool costs and development costs. In injection molding processes in particular, a high quantity is necessary for cost-efficient production.

[0011] In the context of this invention, the terms "insulating element" or "insulation" or "insulated" encompass elements or structures or process steps for sealing and / or closing and / or reinforcing and / or insulating a structural element. These various properties of such an insulating element can occur individually or in combination with one another.

[0012] In an exemplary embodiment, the walls are substantially square and / or rectangular.

[0013] This type of wall design has the advantage of creating a compact insulation element with an essentially cuboidal overall shape. This shape allows for the insulation of a large number of cavities in structural elements.

[0014] In an alternative embodiment, the walls have a substantially round, polygonal, oval or irregular floor plan.

[0015] In an exemplary embodiment, the walls are substantially flat.

[0016] Essentially flat walls offer the advantage that the direction of the expandable material can be optimally directed in the cross-sectional direction of the structural element during its expansion.

[0017] In an exemplary embodiment, the ribs extend substantially orthogonally to the first edges and / or to the second edges.

[0018] Such an alignment of the ribs has the advantage that the expandable material, during its expansion, is efficiently directed toward a wall of the structural element that is opposite to the wall of the structural element to which the insulation element is attached. This allows a large gap between the insulation element and the opposite wall of the structural element to be bridged. Furthermore, such an alignment of the ribs has the advantage that, in vertically running walls of the structural element, it supports the material against the effects of gravity.

[0019] In an alternative embodiment, the ribs extend at an angle relative to an orthogonal to the first edges and / or second edges, wherein the angle is 0° to 30° or 5° to 25° or 5° to 20°.

[0020] The ribs can be angled so that they are aligned essentially parallel, or the ribs can be aligned so that they are arranged at an angle to one another. An angle between the ribs that tapers toward the first edge and opens toward the second edge is particularly advantageous.

[0021] In an exemplary embodiment, the ribs are each at least 60% or 70% or 80% or 90% as long as a total distance between the first edges and the second edges in the direction of the ribs.

[0022] According to the invention, the ribs divide a volume between the two walls in such a way that between 35% and 65% of this volume is arranged between the ribs.

[0023] This division of the volume between the two walls is to be understood as using ribs or, if necessary, their extension to divide the volume.

[0024] Depending on whether an expansion is to be carried out more in the direction of the ribs or more transversely to a direction of the ribs, the volume can be divided differently by the ribs.

[0025] According to the invention, the ribs extend substantially to the first edges of the walls, but are spaced apart from the second edges of the walls by a distance.

[0026] According to the invention, this distance is at least 15% of a length of the ribs.

[0027] In an exemplary embodiment, the expandable material is arranged on 50% to 95% or on 60% to 95% or on 70% to 90% of a base area of ​​the walls.

[0028] The amount of expandable material or the arrangement of the expandable material on the walls can be individually adjusted depending on the expansion rate and the size of the cavity of the structural element without having to change the support of the insulation element.

[0029] According to the invention, an area of ​​the walls immediately adjacent to the second edges is free of expandable material.

[0030] In an exemplary embodiment, a rib is arranged on at least one of the first edges, which rib extends substantially perpendicular to the walls.

[0031] In an exemplary further development, such ribs are arranged on both first edges.

[0032] In an exemplary further development, this rib or these ribs are dimensioned and arranged in such a way that a cross-section of an opening between the two first edges is reduced by at least 10% or at least 20% or at least 30% or at least 40% or at least 50% in comparison to a situation without rib(s).

[0033] In an exemplary further development, this rib or these ribs extend over an entire length of the first edge(s).

[0034] Such ribs on the first edges have the advantage that an expansion direction can be directed away from the opening between the first edges, which can be advantageous depending on the application.

[0035] In an exemplary embodiment, the fastening element is designed as a clip.

[0036] In an exemplary embodiment, the fastening element is formed in one piece and / or from the same material as the carrier.

[0037] In an exemplary embodiment, the insulating element comprises spacer elements which support the insulating element on the structural element when the insulating element is fastened to the structural element by the fastening element.

[0038] Such spacer elements have the advantage that the position of the insulation element in the structural element can be defined more precisely.

[0039] In an exemplary further development, a spacer element is arranged on each side of the fastening element.

[0040] In another exemplary further development, the spacer elements are designed to be flexible.

[0041] In principle, various materials can be used as expandable materials that can be foamed. The material may or may not have reinforcing properties. Typically, the expandable material is expanded thermally, by moisture, or by electromagnetic radiation.

[0042] Such an expandable material typically contains a chemical or physical blowing agent. Chemical blowing agents are organic or inorganic compounds that decompose under the influence of temperature, humidity, or electromagnetic radiation, with at least one of the decomposition products being a gas. Physical blowing agents can be compounds that transform into a gaseous state upon increasing temperature. Therefore, both chemical and physical blowing agents are capable of creating foam structures in polymers.

[0043] The expandable material is preferably thermally foamed using chemical blowing agents. Suitable chemical blowing agents include azodicarbonamides, sulfohydrazides, bicarbonates, or carbonates.

[0044] Suitable blowing agents are also commercially available, for example, under the trade name Expancel ®< from Akzo Nobel, Netherlands, or under the trade name Celogen ®< from Chemtura Corp., USA.

[0045] The heat required for foaming can be introduced by external or internal heat sources, such as an exothermic chemical reaction. The foamable material is preferably foamable at a temperature of ≤ 250°C, in particular from 100°C to 250°C, preferably from 120°C to 240°C, preferably from 130°C to 230°C.

[0046] Suitable expandable materials include, for example, one-component epoxy resin systems that do not flow at room temperature, which, in particular, exhibit increased impact strength and contain thixotropic agents such as Aerosils or nanoclays. For example, such epoxy resin systems comprise 20 to 50 wt.% of a liquid epoxy resin, 0 to 30 wt.% of a solid epoxy resin, 5 to 30 wt.% toughness modifiers, 1 to 5 wt.% physical or chemical blowing agents, 10 to 40 wt.% fillers, 1 to 10 wt.% thixotropic agents, and 2 to 10 wt.% heat-activated hardeners. Suitable toughness modifiers include reactive liquid rubbers based on nitrile rubber or derivatives of polyether polyol polyurethanes, core-shell polymers, and similar systems known to those skilled in the art.

[0047] Also suitable expandable materials are blowing agent-containing, one-component polyurethane compositions composed of crystalline polyesters containing OH groups in a mixture with other polyols, preferably polyether polyols, and polyisocyanates with blocked isocyanate groups. The melting point of the crystalline polyester should be ≥ 50 °C. The isocyanate groups of the polyisocyanate can be blocked, for example, with nucleophiles such as caprolactam, phenols, or benzoxalones. Blocked polyisocyanates, such as those used in powder coating technology and commercially available from Degussa GmbH, Germany, under the trade names Vestagon®< BF 1350 and Vestagon®< BF 1540, are also suitable. Also suitable as isocyanates are so-called encapsulated or surface-deactivated polyisocyanates, which are known to the person skilled in the art and are described, for example, in EP 0 204 970.

[0048] Furthermore, two-component epoxy / polyurethane compositions containing blowing agents, as described, for example, in WO 2005 / 080524 A1, are suitable as expandable materials.

[0049] Ethylene-vinyl acetate compositions containing blowing agents are also suitable as expandable materials.

[0050] Likewise suitable expandable materials are sold, for example, under the trade names SikaBaffle®< 240, SikaBaffle® 250, or SikaBaffle® 255 by Sika Corp., USA, and are described in patents US 5,266,133 and US 5,373,027. Such expandable materials are particularly preferred for the present invention.

[0051] Preferred expandable materials with reinforcing properties include those sold under the trade name SikaReinforcer®< 941 by Sika Corp., USA. These materials are described in US Pat. No. 6,387,470.

[0052] According to the invention, the expandable material has an expansion rate of 1000% to 4000%, particularly preferably 1500% to 3000%. Expandable materials with such expansion rates offer the advantage of achieving reliable sealing or insulation of the structural element against liquids and sound.

[0053] In an exemplary embodiment, the expandable material is formed as a temperature-induced material.

[0054] This has the advantage that the oven can be used to bake the dip coating fluid, expand the expandable material, and thus insulate the cavity. Thus, no additional work step is necessary.

[0055] The carrier can be made of any desired material. Preferred materials are plastics, especially polyurethanes, polyamides, polyesters, and polyolefins, preferably high-temperature-resistant polymers such as poly(phenylene ethers), polysulfones, or polyethersulfones, which are also particularly foamed; metals, especially aluminum and steel; or natural organic materials, especially wood or other (pressed) fiber materials or glass-like or ceramic materials; especially also foamed materials of this type; or any desired combination of these materials. Particular preference is given to using polyamide, especially polyamide 6, polyamide 6,6, polyamide 11, polyamide 12, or a mixture thereof.

[0056] Furthermore, the carrier can have any desired structure and design. For example, it can be solid, hollow, foamed, or have a lattice-like structure. The surface of the carrier can typically be smooth, rough, or textured.

[0057] For insulation elements in which the expandable material is mounted on a carrier, the manufacturing process differs depending on whether the carrier is made of a material that can be processed by injection molding or not. If this is the case, a two-component injection molding process is typically used. A first component, in this case the carrier, is injected first. After this first component has solidified, the cavity in the mold is enlarged or adjusted, or the manufactured injection-molded part is placed in a new mold, and a second component, in this case the expandable material, is injected onto the first component using a second injection unit.

[0058] If the carrier is made of a material that cannot be manufactured using the injection molding process, such as metal, the carrier is placed in a suitable mold and the expandable material is molded onto the carrier. Of course, it is also possible to attach the expandable material to the carrier using special fastening devices or processes.

[0059] Furthermore, carriers can also be produced by other processes, for example by extrusion.

[0060] The problem posed at the outset is further solved by a system in a motor vehicle, the system comprising: a structural element having a cavity; and an insulating element according to the above description; wherein the insulating element is arranged in the cavity of the structural element.

[0061] In an exemplary embodiment, the structural element is a portion of a pillar or beam or strut of a body of a motor vehicle.

[0062] Details and advantages of the invention are described below using exemplary embodiments and with reference to schematic drawings. They show: Fig. 1 shows an exemplary representation of a body; Fig. 2 shows a schematic representation of an exemplary support; Fig. 3 shows a schematic representation of an exemplary insulating element; Figs. 4a to 4c show a schematic representation of an exemplary insulating element; Fig. 5 shows a schematic representation of an exemplary insulating element; and Fig. 6 shows a schematic representation of an exemplary insulating element.

[0063] In Fig. 2A support 11 is shown schematically and by way of example. The support 11 has a first wall 2 and a second wall 3, which are designed and arranged essentially congruently. The two walls 2, 3 each have a first edge 4 and a second edge 5. A first rib 6 and a second rib 7 are arranged between the first wall 2 and the second wall 3. These ribs 6, 7 each extend between the first edges 4 and the second edges 5 of the walls 2, 3. The ribs 6, 7 are each at least half as long as a total distance between the first edges 4 and the second edges 5 in the direction of the ribs 6, 7.

[0064] In this embodiment, the walls 2, 3 have a rectangular plan and are flat. Furthermore, the walls in this embodiment have a rib on each of the first edges 4, which extends perpendicular to the walls 2, 3.

[0065] In Fig. 31 shows a schematic and exemplary insulating element 16. The support in turn comprises a first wall 2 and a second wall 3, each of which has a first edge 4 and a second edge 5. The expandable material 13 is arranged between the walls 2, 3. The ribs are not visible in this illustration because, in this exemplary embodiment, they are completely enclosed by the expandable material 13. The insulating element 16 further comprises a fixing element 8, which is arranged in a region of the first edges 4 of the walls 2, 3. In this exemplary embodiment, the fixing element 8 is designed as a clip.

[0066] In the Fig. 4a to 4c Another exemplary insulation element 16 is shown schematically. The insulation element 16 is in Fig. 4a shown in a side view, and in the Fig. 4b and 4c the same insulation element 16 is then along the section line AA of the Fig. 4A shown.

[0067] In the sectional view of the Fig. 4b it can be seen that the expandable material 13 is arranged on both sides of the ribs 6, 7.

[0068] In the sectional view of the Fig. 4c A first direction 17 and a second direction 18 are also shown. Due to the specific arrangement of the ribs 6, 7, the expandable material 13 is guided more strongly in the first direction 17 during its expansion by creating a channel effect between the ribs 6, 7. This allows the expandable material 13 to expand further in the first direction than would be the case without the ribs 6, 7.

[0069] With a horizontal alignment of the structural element (not shown), the insulation element 16 can be oriented in the room as shown in Fig. 4cshown. In such a case, the ribs 6, 7, in this embodiment the first rib 6, support the expansion of the expandable material 13 in the second direction 18. In such situations, the problem arises that the expandable material 13 can be undesirably deflected by gravity during its expansion. In this case, rib 6 provides support for the expandable material 13, so that the expandable material 13 can expand further in the second direction 18 than would be the case without the first rib 6.

[0070] In the Figs. 5 and 6 Two further exemplary embodiments of insulation elements 16 are shown schematically. In these embodiments, the insulation element 16 additionally has spacer elements 9. In Fig. 5 These spacer elements 9 are arranged on both sides of the fixing element 8. And in Fig. 6These spacer elements 9 are each formed as extensions of the first wall 2 and the second wall 3 in the region of the first edge 4. In these embodiments, the ribs and the expandable material are not visible. List of reference symbols

[0071] 2First wall 3Second wall 4First edge 5Second edge 6First rib 7Second rib 8Fixing element 9Spacer element 10Body 11Beam 12Structural element 13Expandable material 14Structural element 16Insulating element 17First direction 18Second direction

Claims

1. Insulating element (16) for insulating a structural element (12, 14) in a motor vehicle, the insulating element (16) comprising: a carrier (11) with a first wall (2) and a second wall (3), wherein the walls (2, 3) are designed and disposed so as to be substantially congruent, and wherein the walls (2, 3) each have opposite first edges (4) and second edges (5), and with a first rib (6) and a second rib (7), wherein the ribs (6, 7) are disposed between the walls (2, 3), and wherein the ribs (6, 7) each extend between the first edge (4) and the second edge (5), wherein the ribs (6, 7) each are at least half as long as a total distance between the first edges (4) and the second edges (5) in the direction of the ribs (6, 7); an expandable material (13) which is disposed between the walls (2, 3) and which is in each case disposed on both sides of the ribs (6, 7); and a fixing element (8) for fixing the insulating element (16) in the structural element (12, 14), wherein the fixing element (8) is disposed in a region of the first edges (4) of the walls (2, 3) ; wherein the ribs (6, 7) subdivide a volume between the two walls (2, 3) in such a manner that between 35% and 65% of this volume is disposed between the ribs (6, 7); and wherein the ribs (7) extend substantially up to the first edges (4) of the walls (2, 3), but are spaced apart from the second edges (5) of the walls (2, 3) by a spacing, wherein this spacing is at least 15% of a length of the ribs (6, 7), characterized in that the expandable material (13) has an expansion rate of 1000% to 4000%; and in that one region of the walls (2, 3) directly on the second edges (5) is in each case free of expandable material (13).

2. Insulating element (16) according to Claim 1, wherein the walls (2, 3) are configured so as to be substantially quadrangular and / or rectangular and / or flat.

3. Insulating element (16) according to one of the preceding claims, wherein the ribs (6, 7) extend so as to be substantially orthogonal to the first edges (4) and / or second edges (5).

4. Insulating element (16) according to one of Claims 1 or 2, wherein the ribs (6, 7) extend at an angle relative to an orthogonal to the first edges (4) and / or second edges (5), wherein the angle is 0° to 30°, or 5° to 25°, or 5° to 20°.

5. Insulating element (16) according to one of the preceding claims, wherein the ribs (6, 7) are in each case at least 60% or 70% or 80% or 90% as long as a total distance between the first edges (4) and the second edges (5) in the direction of the ribs (6, 7).

6. Insulating element (16) according to one of the preceding claims, wherein the ribs (6, 7) subdivide a volume between the two walls (2, 3) in such a manner that between 40% and 60% of this volume is disposed between the ribs (6, 7).

7. Insulating element (16) according to one of the preceding claims, wherein the expandable material (13) is disposed on 50% to 95%, or 60% to 95%, or 70% to 90%, of a base area of the walls (2, 3).

8. Insulating element (16) according to one of the preceding claims, wherein the fixing element (8) is designed as a clip, and / or wherein the fixing element (8) is configured so as to be integral to the carrier (11).

9. Insulating element (16) according to one of the preceding claims, wherein the insulating element (16) comprises one or a plurality of spacer elements (9) which support the insulating element (16) on the structural element (12, 14) when the insulating element (16) is fastened to the structural element (12, 14) by way of the fixing element (8).

10. Insulating element (16) according to Claim 9, wherein one spacer element (9) is in each case disposed on one side of the fixing element (8), and / or wherein the spacer elements (9) are configured so as to be flexible.

11. System in a motor vehicle, the system comprising: a structural element (12, 14) which has a cavity; and an insulating element (16) according to one of Claims 1 to 10; wherein the insulating element (16) is disposed in the cavity of the structural element (12, 14).