Insulating element
Patent Information
- Application Number
- EP2023739509
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-07-14
- Filing Date
- 2023-07-06
- Publication Date
- 2025-05-21
AI Technical Summary
Existing insulating and reinforcing elements for vehicle cavities require custom manufacturing for each shape and size, leading to high development and production costs, especially for small series, and often suffer from inadequate expansion and connection issues.
An insulating element with an H-shaped carrier, side walls, and expandable materials, where the side walls prevent slippage and direct expansion, and penetrations in the intermediate wall enhance the connection between the carrier and expandable materials, allowing for targeted and efficient expansion.
This solution reduces costs and improves the connection and expansion efficiency of insulating elements, providing a reliable seal and noise reduction for vehicle cavities while maintaining lightweight construction.
Smart Images
Figure 1.1
Abstract
Description
[0001] INSULATION ELEMENT
[0002] The invention relates to an insulating element for insulating a structural element in a motor vehicle, as well as a method for producing such insulating elements.
[0003] 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.
[0004] 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.
[0005] Fig. 1 schematically illustrates the body of an automobile. 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. These elements 16 are typically manufactured using a two-component injection molding process.
[0006] The disadvantage of previously known sealing and / or reinforcement elements is that a custom-made element must be manufactured for each body shape and each cavity, necessitating new injection molding tools for each application. This leads to high development and manufacturing costs and is particularly disadvantageous for smaller vehicle series.
[0007] For this reason, sealing elements have already been proposed that are not manufactured using a two-component injection molding process. For example, WO 2016 / 176459 A1 discloses a process in which activatable material is extruded onto a carrier. However, the disadvantage of this solution is that the activatable material often expands in an undesirable manner or does not expand in a targeted manner, and the bond between the carrier and the activatable material is often insufficiently strong.
[0008] 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-batch production, and reduce overall development and manufacturing costs for the insulating elements, as well as allow for targeted and efficient expansion of the activatable material.
[0009] This object is initially achieved by an insulating element for insulating a structural element in a motor vehicle, the insulating element comprising: a support which has an intermediate wall, a first side wall and a second side wall, wherein the walls of the support extend along a common longitudinal axis, and wherein the support has an H-shaped cross-section in a plane perpendicular to the longitudinal axis, in which cross-section the first side wall and the second side wall are each arranged at one end of the intermediate wall; an expandable material which is arranged both between the side walls and on both sides of the intermediate wall; and at least one fixing element which penetrates both the support and the expandable material and is arranged substantially perpendicular to the intermediate wall of the support.
[0010] A key idea of the present invention is that, on the one hand, the shape of the carrier better bonds the expandable material to the carrier, as the side walls effectively prevent the expandable material from slipping sideways during expansion. On the other hand, this shape also more precisely defines the direction of expansion, as the side walls guide the expandable material in a desired direction during expansion.
[0011] A further advantage of the proposed support design is that the side walls provide mechanical protection for the expandable material. This is particularly important during transport, storage, or installation of the insulation elements.
[0012] 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 insulating a structural element. These various properties of such an insulating element can occur individually or in combination with one another.
[0013] Insulating element
[0014] In an exemplary embodiment, the partition wall has at least one penetration.
[0015] Such a design of the partition wall has the advantage of further improving the connection between the support and the expandable material, as the expandable material is connected to each other on both sides of the partition wall through the penetration. This creates a mechanical interlock between the expandable material and the support, making it more difficult for the expandable material to detach from the support.
[0016] In an exemplary embodiment, the partition wall has several penetrations, which are spaced apart from one another at regular intervals along the longitudinal axis. In an exemplary embodiment, at least one penetration is circular, oval, or elliptical.
[0017] In an exemplary further development, the plurality of penetrations along the longitudinal axis are arranged essentially centrally on the partition wall.
[0018] In an exemplary embodiment, the side walls are mirror-symmetrical to one another.
[0019] This design of the side walls has the advantage that the insulation element can be installed with the first side wall facing upwards as well as with the second side wall facing upwards without resulting in a different expansion behavior. This eliminates or reduces the risk of manipulation errors during installation.
[0020] In an exemplary embodiment, the side walls have a substantially C- or U-shaped cross-section, with one open side of this cross-section being oriented in the direction of the other side wall.
[0021] Such a design has the advantage that the expandable material is protected from mechanical influences even in corner areas of the insulation element, and that targeted expansion vertically away from the partition wall can be achieved.
[0022] In an exemplary embodiment, the expandable material comprises a first expandable material and a second expandable material, wherein the intermediate wall of the carrier is arranged between the first expandable material and the second expandable material.
[0023] In an exemplary embodiment, the first expandable material and the second expandable material have the same chemical composition. In an alternative embodiment, the first expandable material and the second expandable material do not have the same chemical composition. In particular, the materials may differ with respect to an expansion rate.
[0024] In an exemplary embodiment, a cross section of the first expandable material perpendicular to the longitudinal axis is smaller than a cross section of the second expandable material perpendicular to the longitudinal axis.
[0025] Such a design has the advantage that expansion can be more pronounced on a side of the insulation element facing away from the structural element (to which the insulation element is attached by the fixing element) than on a side facing the structural element. This allows the expandable material to be used more economically.
[0026] In an exemplary embodiment, the first expandable material and the second expandable material are connected to each other through the at least one penetration.
[0027] Such a design has the advantage that the connection between the carrier and the expandable material can be further improved.
[0028] In an exemplary embodiment, the insulating element has at least two fixing elements for fixing the insulating element to the structural element.
[0029] In an exemplary embodiment, the at least one fixation element is designed as a nail with barbs.
[0030] Expandable material
[0031] 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.
[0032] 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.
[0033] The expandable material is preferably thermally foamed using chemical blowing agents. Suitable chemical blowing agents include azodicarbonamides, sulfohydrazides, bicarbonates, or carbonates.
[0034] 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., LISA.
[0035] 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.
[0036] 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.
[0037] Other suitable expandable materials are blowing agent-containing, one-component polyurethane compositions composed of crystalline, OH-containing polyesters mixed 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 those skilled in the art and are described, for example, in EP 0 204 970.
[0038] Furthermore, two-component epoxy / polyurethane compositions containing blowing agents, as described, for example, in WO 2005 / 080524 Al, are suitable as expandable materials.
[0039] Ethylene-vinyl acetate compositions containing blowing agents are also suitable as expandable materials.
[0040] 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.
[0041] 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. In an exemplary embodiment, the expandable material has an expansion rate of 800% to 5000%, preferably 1000% to 4000%, and particularly preferably 1500% to 3000%. Expandable materials with such expansion rates offer the advantage of reliably sealing or insulating the structural element against liquids and sound.
[0042] In an exemplary embodiment, the expandable material is formed as a temperature-induced material.
[0043] 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.
[0044] carrier
[0045] 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.
[0046] The carrier can be manufactured using various processes. In a first embodiment, the carrier is manufactured using an injection molding process. In a second embodiment, the carrier is manufactured using an extrusion process. In a third embodiment, the carrier is manufactured using an additive manufacturing process.
[0047] The object stated at the outset is also achieved by a method for producing an insulating element for insulating a structural element in a motor vehicle, the method comprising the steps of: providing a carrier which has an intermediate wall, a first side wall and a second side wall, wherein the walls of the carrier extend along a common longitudinal axis, and wherein the carrier has an H-shaped cross-section in a plane perpendicular to the longitudinal axis, in which cross-section the first side wall and the second side wall are each arranged at one end of the intermediate wall; extruding a first expandable material onto a first side of the intermediate wall of the carrier; and extruding a second expandable material onto a second side of the intermediate wall of the carrier.
[0048] In an exemplary embodiment, the extrusion of the first expandable material and the extrusion of the second expandable material occur simultaneously in a co-extrusion process.
[0049] Such a process has the advantage that the expandable material can be arranged on the carrier in one operation.
[0050] In an exemplary embodiment, the carrier is formed by extrusion.
[0051] Such a process has the advantage that the carrier and expandable material are both produced by extrusion, so that the entire insulation element can be manufactured in one efficient process and in one production line.
[0052] In an exemplary embodiment, after the carrier has been formed, at least one penetration is punched into the intermediate wall of the carrier.
[0053] Such a method has the advantage of enabling the expandable material to be connected through the partition wall, thereby improving the bond between the carrier and the expandable material. In an exemplary embodiment, the fixing element is manually driven through the expandable material and through the partition wall of the carrier.
[0054] In an alternative embodiment, the fixing element is mechanically driven through the expandable material and through the intermediate wall of the carrier.
[0055] In an exemplary embodiment, the fixing element is guided through a penetration of the intermediate wall of the carrier.
[0056] Details and advantages of the invention are described below using exemplary embodiments and with reference to schematic drawings. They show:
[0057] Fig. 1 is an exemplary representation of a body;
[0058] Fig. 2 is a schematic representation of an exemplary insulation element; and
[0059] Fig. 3 is a schematic representation of an exemplary carrier.
[0060] Fig. 2 shows a schematic and exemplary cross-sectional view of an insulating element 1. The insulating element 1 has a carrier 2, expandable material 3, and a fixing element 4. The expandable material 3 comprises a first expandable material 3.1 and a second expandable material 3.2, which are arranged on both sides of an intermediate wall of the carrier 2. The fixing element 4 is driven through both the carrier 2 and the expandable material 3. In an installed state (not shown), the fixing element 4 is also inserted through a provided opening in a structural element of the body. Fig. 3 shows a schematic and exemplary view of a carrier 2. The carrier 2 comprises an intermediate wall 2.1, a first side wall 2.2, and a second side wall 2.3. The side walls 2.2, 2.3 have a C- or U-shaped cross-section and are mirror-symmetrical to one another. The intermediate wall 2.1 has several circular penetrations 6. The walls 2.1, 2.2, 2.3 of the support 2 extend along a longitudinal axis 5. These walls 2.1, 2.2, 2.3 form an H-shaped cross section in a cross section which is perpendicular to the longitudinal axis 5.
[0061] List of reference symbols
[0062] 1 insulation element
[0063] 2 carriers
[0064] 2.1 Partition wall
[0065] 2.2 first side wall
[0066] 2.3 second side wall
[0067] 3 expandable material
[0068] 3.1 first expandable material
[0069] 3.2 second expandable material
[0070] 4 Fixing element
[0071] 5 Longitudinal axis
[0072] 6 Penetration
[0073] 10 Body
[0074] 12 Structural element
[0075] 14 Structural element
[0076] 16 Sealing or reinforcing element
Claims
Patent claims 1. Insulating element (1) for insulating a structural element in a motor vehicle, the insulating element (1) comprising: a support (2) which has an intermediate wall (2.1), a first side wall (2.2), and a second side wall (2.3), wherein the walls (2.1, 2.2, 2.3) of the support extend along a common longitudinal axis (5), and wherein the support (2) has an H-shaped cross-section in a plane perpendicular to the longitudinal axis (5), in which the first side wall (2.2) and the second side wall (2.3) are each arranged at one end of the intermediate wall (2.1); an expandable material (3) which is arranged both between the side walls (2.2, 2.3) and on both sides of the intermediate wall (2.1); and at least one fixing element (4) which penetrates both the carrier (2) and the expandable material (3) and is arranged substantially perpendicular to the intermediate wall (2.1) of the carrier (2).
2. Insulating element (1) according to claim 1, wherein the intermediate wall (2.1) has at least one penetration (6).
3. Insulating element (1) according to claim 2, wherein the intermediate wall (2.1) has a plurality of penetrations (6) which are spaced apart from one another in particular at regular intervals in the direction of the longitudinal axis (5).
4. Insulating element (1) according to one of claims 2 or 3, wherein the at least one penetration (6) is circular, oval or elliptical.
5. Insulating element (1) according to one of the preceding claims, wherein the side walls (2.2, 2.3) are mirror-symmetrical to one another.
6. Insulating element (1) according to one of the preceding claims, wherein the side walls (2.2, 2.3) have a substantially C- or U-shaped cross-section, wherein an open side of this cross-section is oriented in the direction of the other side wall (2.2, 2.3).
7. Insulating element (1) according to one of the preceding claims, wherein the expandable material (3) comprises a first expandable material (3.1) and a second expandable material (3.2), wherein the intermediate wall (2.1) of the carrier (2) is arranged between the first expandable material (3.1) and the second expandable material (3.2).
8. Insulating element (1) according to one of the preceding claims, wherein a cross section of the first expandable material (3.1) perpendicular to the longitudinal axis (5) is smaller than a cross section of the second expandable material (3.2) perpendicular to the longitudinal axis (5).
9. Insulating element (1) according to one of claims 2 to 8, wherein the first expandable material (3.1) and the second expandable material (3.2) are connected to one another through the at least one penetration (6).
10. Insulating element (1) according to one of the preceding claims, wherein the insulating element (1) has at least two fixing elements (4) for fixing the insulating element (1) to the structural element, and / or wherein the at least one fixing element (4) is designed as a nail with barbs.
11. A method for producing an insulating element (1) for insulating a structural element in a motor vehicle, the method comprising the steps: Providing a support (2) which has an intermediate wall (2.1), a first side wall (2.2) and a second side wall (2.3), wherein the walls (2.1, 2.2, 2.3) of the support extend along a common longitudinal axis (5), and wherein the support (2) has an H-shaped cross-section in a plane perpendicular to the longitudinal axis (5), in which the first side wall (2.2) and the second side wall (2.3) are each arranged at one end of the intermediate wall (2.1); Extruding a first expandable material (3.1) onto a first side of the intermediate wall (2.1) of the support (2); and Extruding a second expandable material (3.2) onto a second side of the intermediate wall (2.1) of the support (2).
12. The method according to claim 11, wherein the extrusion of the first expandable material (3.1) and the extrusion of the second expandable material (3.2) take place simultaneously in a co-extrusion process.
13. Method according to one of claims 11 or 12, wherein the carrier (2) is formed by extrusion, and / or wherein after forming the carrier (2) at least one penetration (6) is punched into the intermediate wall (2.1) of the carrier (2).