Blocking element

Abstract

A blocking element for blocking a structural element inside a motor vehicle, the blocking element comprising a carrier having an intermediate wall, a first side wall, and a second side wall, wherein the walls of the carrier extend along a common longitudinal axis, the carrier having an H-shaped cross-section in a plane perpendicular to the longitudinal axis, in which H-shaped cross-section the first side wall and the second side wall are each arranged at one end of the intermediate wall. The blocking element further comprises an expandable material arranged between both side walls and on both sides of the intermediate wall, and at least one fixing element passing through both the carrier and the expandable material and arranged substantially perpendicular to the intermediate wall of the carrier.

Description

Technical Field

[0001] The present invention relates to a blocking element for blocking structural elements of a vehicle and a method for manufacturing such a blocking element.

Background Art

[0002] In many cases, for example, components such as those of means of transport and means of locomotion, in particular of vehicles on water or on land, or of aircraft, such as the body and / or frame, have a structure with cavities in order to enable a lightweight construction. However, these cavities cause various problems. Depending on the type of cavity, the cavity needs to be sealed to prevent the ingress of moisture and contaminants that lead to corrosion of the component. Also, it is often desirable to significantly reinforce the cavity and, by extension, the component while maintaining a low weight. Also, it is often necessary to stabilize the cavity and, by extension, the part in order to reduce the noise transmitted along or through the cavity. Many such cavities have an irregular shape or narrow dimensions, making it difficult to seal, reinforce, and block them properly.

[0003] For this reason, especially in automotive construction, but also in aircraft and ship construction, sealing elements (baffles) are used to seal the cavities and / or to acoustically block them, or reinforcing elements (reinforcements) are used to reinforce the cavities.

[0004] FIG. 1 schematically shows a vehicle body. The vehicle body 10 has various structures with cavities such as pillars 14 and beams, or side sills 12. Structural elements 12, 14 having such cavities are usually sealed or reinforced by sealing elements and / or reinforcing elements 16. These elements 16 are usually manufactured using a two-component injection molding method.

[0005] A disadvantage of the sealing elements and / or reinforcing elements known to date is that elements adapted individually to each body shape and each cavity of the body have to be manufactured, and thus new injection molding tools are required for each application. This leads to high development and production costs, which is particularly disadvantageous for small vehicle series.

[0006] For these reasons, sealing elements not manufactured using a two-component injection molding method have already been proposed. For example, WO 2016 / 176459 A1 discloses a method in which an activatable material is extruded onto a carrier. However, in this solution, it is disadvantageous that the activatable material often expands in an undesirable manner, or does not expand as desired, and that the bond between the carrier and the activatable material is often not sufficiently strong. SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION

[0007] Accordingly, it is an object of the present invention to provide an improved blocking element for blocking structural elements of a motor vehicle that avoids the disadvantages of the prior art. The blocking element should in particular provide economic advantages in the case of small series, reduce the overall development and production costs of the blocking element, and enable an efficient expansion of the activatable material as desired. MEANS FOR SOLVING THE PROBLEM

[0008] This problem is first solved by a blocking element for blocking structural elements within a motor vehicle, the blocking element comprising a carrier having a middle wall, a first side wall, and a second side wall, where the walls of the carrier extend along a common longitudinal axis, the carrier having an H-shaped cross-section in a plane perpendicular to the longitudinal axis, in which H-shaped cross-section the first side wall and the second side wall are each arranged at one end of the middle wall, an expandable material arranged between both side walls and on both sides of the middle wall, and at least one fixing element passing through both the carrier and the expandable material and arranged substantially perpendicular to the middle wall of the carrier.

[0009] The central idea of the present invention is, in particular, that due to the shape of the carrier, on the one hand, the side walls effectively prevent the expandable material from slipping sideways during expansion, so that the expandable material bonds better to the carrier. On the other hand, due to this shape, the side walls guide the expandable material in the desired direction during expansion, so that the expansion direction is defined more precisely.

[0010] A further advantage of the shape of the carrier proposed in this specification is that the side walls mechanically protect the expandable material. This is particularly important when transporting, storing, or installing the blocking element.

[0011] The terms "blocking element", or "blocking", or "to block" include, in relation to the present invention, elements, or structures, or method steps for the isolation of and / or for the sealing of and / or for the blocking of structural elements. These various properties of such blocking elements can occur individually or in combination with each other in that case.

[0012] "Blocking element" In an exemplary embodiment, the middle wall has at least one through-hole.

[0013] Such a configuration of the intermediate wall has the advantage of further improving the bond between the carrier and the expandable material by bonding the expandable material to both sides of the intermediate wall through the through-holes. Thereby, a mechanical bond is created between the expandable material and the carrier, making it difficult for the expandable material to come off the carrier.

[0014] In an exemplary deployment, the intermediate wall has a plurality of through-holes, which are spaced apart from each other at regular intervals, particularly in the longitudinal axis direction.

[0015] In an exemplary deployment, at least one through-hole is circular, oval, or elliptical.

[0016] In an exemplary deployment, the plurality of through-holes are arranged substantially at the center of the intermediate wall along the longitudinal axis.

[0017] In an exemplary embodiment, the two side walls are formed mirror-symmetric to each other.

[0018] Such a configuration of the two side walls has the advantage that the blocking element can be installed without another expansion behavior occurring when the first side wall faces upward and the second side wall faces upward. Thereby, work errors during installation can be eliminated or reduced.

[0019] In an exemplary embodiment, the two side walls have a substantially C-shaped or U-shaped cross-section, and the open sides of this cross-section are directed towards the other side wall respectively.

[0020] Such a configuration has the advantage that the expandable material is also protected from mechanical effects at the corners of the blocking element, and further, the target expansion can be achieved at a position vertically away from the intermediate wall.

[0021] In an exemplary embodiment, the expandable material includes a first expandable material and a second expandable material, and the intermediate wall of the carrier is arranged between the first expandable material and the second expandable material.

[0022] In an exemplary deployment, the first expandable material and the second expandable material are composed of the same chemical composition.

[0023] In an alternative deployment, the first expandable material and the second expandable material are composed of different chemical compositions. In particular, the materials may differ with respect to the expansion rate.

[0024] In an exemplary embodiment, a cross-section perpendicular to the longitudinal axis of the first expandable material is smaller than a cross-section perpendicular to the longitudinal axis of the second expandable material.

[0025] Such a configuration has the advantage that the expansion on one side of the blocking element, which is opposite to the (structural element to which the blocking element is attached by the fixing element), can be made larger than the expansion on the side facing the structural element. Thereby, the expandable material can be used more economically.

[0026] In an exemplary embodiment, the first expandable material and the second expandable material are connected via at least one through-hole.

[0027] Such a configuration has the advantage that the connection between the carrier and the expandable material can be further improved.

[0028] In an exemplary embodiment, the blocking element has at least two fixing elements for fixing the blocking element to the structural element.

[0029] In an exemplary embodiment, at least one fixing element is formed as a barbed nail.

[0030] "Expandable material" Basically, various foamable materials can be used as the expandable material. This material may or may not have reinforcing properties. Typically, the expandable material expands by heat, moisture, or electromagnetic radiation.

[0031] Such expandable materials typically have a chemical or physical blowing agent. A chemical blowing agent is an organic or inorganic compound that decomposes under the influence of temperature, moisture, or electromagnetic radiation, with at least one of the decomposition products being a gas. As a physical blowing agent, for example, a compound that changes to a gaseous state upon an increase in temperature can be used. Thereby, both chemical and physical blowing agents can generate a foam structure in the polymer.

[0032] Preferably, the expandable material is thermally foamed using a chemical blowing agent. Suitable chemical blowing agents include, for example, azodicarbonamide, sulfohydrazide, bicarbonate, or carbonate. Suitable blowing agents are commercially available, for example, under the trade name Expancel® from Akzo Nobel in the Netherlands or under the trade name Celogen® from Chemtura Corp. in the United States. The heat required for foaming can be introduced by an external or internal heat source, such as an exothermic chemical reaction. The foamable material is preferably foamable at a temperature of 250 °C or lower, particularly 100 °C to 250 °C, preferably 120 °C to 240 °C, preferably 130 °C to 230 °C.

[0033] As the expandable material, for example, a one-component epoxy resin system that does not flow at room temperature is suitable, and the epoxy resin system particularly has high impact resistance and contains a thixotropic agent such as Aerosil or nanoclay. For example, such an epoxy resin system has 20 to 50 wt% of an epoxy liquid resin, 0 to 30 wt% of an epoxy solid resin, 5 to 30 wt% of an impact resistance improver, 1 to 5 wt% of a physical or chemical blowing agent, 10 to 40 wt% of a filler, 1 to 10 wt% of a thixotropic agent, and 2 to 10 wt% of a heat-activated curing agent. As the impact resistance improver, a reactive liquid rubber based on a derivative of nitrile rubber or polyether polyol polyurethane, a core-shell polymer, and similar systems known to those skilled in the art are suitable.

[0034] Similarly, a suitable expandable material is a one-component polyurethane composition containing a blowing agent, and the polyurethane composition is synthesized from a crystalline polyester having OH groups in a mixture with a further polyol, preferably a polyether polyol, and a polyisocyanate having blocked isocyanate groups. The melting point of the crystalline polyester needs to be 50 °C or higher. The isocyanate groups of the polyisocyanate can be blocked by a nucleophilic agent such as, for example, caprolactam, phenol or benzoxalon. Furthermore, blocked polyisocyanates such as those used in powder coating technology are also suitable, which are commercially available, for example, under the trade names Vestagon® BF1350 and Vestagon® BF1540 from Degussa GmbH of Germany. As the isocyanate, so-called encapsulated polyisocyanates or surface-inactivated polyisocyanates are also suitable, which are known to those skilled in the art and are described, for example, in European Patent No. 0204970.

[0035] Furthermore, as the expandable material, a two-component epoxy / polyurethane composition containing a blowing agent, such as that described in Pamphlet of International Publication No. 2005 / 080524A1, is also suitable.

[0036] Furthermore, an ethylene vinyl acetate composition containing a blowing agent is also suitable as the expandable material.

[0037] Similarly, suitable expandable materials are commercially available, for example, under the trade names SikaBaffle® 240, SikaBaffle® 250, or SikaBaffle® 255 from Sika corp. of the United States and are described in U.S. Patent No. 5266133 and U.S. Patent No. 5373027. Such expandable materials are particularly preferred for the present invention.

[0038] As the expandable material having reinforcing properties, for example, those sold under the trade name of SikaReinforcer (registered trademark) 941 by Sika corp. of the United States are preferable. These are described in U.S. Patent No. 6387470.

[0039] 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%. The expandable material having such an expansion rate provides the advantage that a highly reliable seal or block of the structural element against liquid and sound can be achieved.

[0040] In an exemplary embodiment, the expandable material is formed as a temperature-induced material.

[0041] This has the advantage that an oven can be used for baking the dip coating liquid in order to expand the expandable material and thereby block the cavity. Thereby, no additional working steps are required.

[0042] "Carrier" The carrier can be composed of any material. Preferred materials are plastics, particularly polyurethane, polyamide, polyester, and polyolefin, preferably high-temperature resistant polymers such as poly(phenylene ether), polysulfone, or polyethersulfone, especially when foamed, metals, particularly aluminum and steel, or growing organic materials, particularly wood or other (pressed) fiber materials, or glassy or ceramic materials, especially this kind of foamed materials, or any combination of these materials. Particularly preferably, polyamide, particularly polyamide 6, polyamide 6,6, polyamide 11, polyamide 12, or a mixture thereof is used.

[0043] Carriers can be manufactured using various methods. In a first exemplary embodiment, the carrier is manufactured using an injection molding method. In a second exemplary embodiment, the carrier is manufactured using an extrusion molding method. In a third exemplary embodiment, the carrier is manufactured using an additional manufacturing method.

[0044] "Manufacturing method" The above-mentioned problem is also solved by a method for manufacturing a blocking element for blocking a structural element of a motor vehicle, the method comprising the steps of providing a carrier having an intermediate wall, a first side wall, and a second side wall, wherein the walls of the carrier extend along a common longitudinal axis, the carrier has an H-shaped cross-section in a plane perpendicular to the longitudinal axis, and in this 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 to the first side of the intermediate wall of the carrier, and extruding a second expandable material to the second side of the intermediate wall of the carrier.

[0045] In an exemplary embodiment, the extrusion of the first expandable material and the extrusion of the second expandable material are performed simultaneously in a co-extrusion molding method.

[0046] Such a process has the advantage that the expandable material can be placed on the carrier in a single working step.

[0047] In an exemplary embodiment, the carrier is formed by extrusion molding.

[0048] Such a method has the advantage that the entire blocking element can be manufactured in one efficient method and on one production line because the carrier and the expandable material are both manufactured by extrusion molding.

[0049] In an exemplary embodiment, after the formation of the carrier, at least one through-hole is punched and formed in the intermediate wall of the carrier.

[0050] Such a method has the advantage that the expandable material can be joined through the intermediate wall, thereby improving the bond between the carrier and the expandable material.

[0051] In an exemplary embodiment, the fixing element is pushed in by hand through the expandable material and through the intermediate wall of the carrier.

[0052] In an alternative embodiment, the fixing element is mechanically pushed through the expandable material and through the intermediate wall of the carrier.

[0053] In an exemplary embodiment, the fixing element is guided through the through-hole of the intermediate wall of the carrier.

[0054] The details and advantages of the present invention will be described below based on examples and in relation to schematic drawings.

Brief Description of the Drawings

[0055]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0056] In FIG. 2, the blocking element 1 is schematically and exemplarily shown in cross-section. The blocking element 1 has a carrier 2, an expandable material 3, and a fixing element 4. The expandable material 3 includes a first expandable material 3.1 and a second expandable material 3.2 disposed on both sides of the intermediate wall of the carrier 2. The fixing element 4 is pushed through both the carrier 2 and the expandable material 3. In the installed state (not shown), the fixing element 4 is also inserted into an opening provided in the structural element of the vehicle body.

[0057] Figure 3 schematically and illustratively shows a carrier 2. The carrier 2 includes an intermediate wall 2.1, a first side wall 2.2, and a second side wall 2.3. Both side walls 2.2 and 2.3 have a C-shaped or U-shaped cross section and are formed mirror-symmetric to each other. The intermediate wall 2.1 has a plurality of circular through-holes 6. The walls 2.1, 2.2, 2.3 of the carrier 2 extend along the longitudinal axis 5. These walls 2.1, 2.2, 2.3 form an H-shaped cross section in a cross section perpendicular to the longitudinal axis 5.

Explanation of Reference Numerals

[0058] 1 Shut-off element 2 Carrier 2.1 Intermediate wall 2.2 First side wall 2.3 Second side wall 3 Expansive material 3.1 First expansive material 3.2 Second expansive material 4 Fixing element 5 Longitudinal axis 6 Through-hole 10 Vehicle body 12 Structural element 14 Structural element 16 Sealing element or reinforcing element

Claims

1. A blocking element (1) for blocking a structural element within a motor vehicle, comprising: A carrier (2) having a middle wall (2.1), a first side wall (2.2), and a second side wall (2.3), wherein these walls (2.1, 2.2, 2.3) of the carrier extend along a common longitudinal axis (5), and the carrier (2) has an H-shaped cross-section in a plane perpendicular to the longitudinal axis (5), and in the H-shaped cross-section, the first side wall (2.2) and the second side wall (2.3) are each disposed at one end of the middle wall (2.1); An expandable material (3) disposed between the two side walls (2.2, 2.3) and on both sides of the middle wall (2.1); and At least one fixing element (4) passing through both the carrier (2) and the expandable material (3) and disposed substantially perpendicular to the middle wall (2.1) of the carrier (2).

2. The blocking element (1) according to claim 1, wherein the middle wall (2.1) has at least one through-hole (6).

3. The blocking element (1) according to claim 2, wherein the middle wall (2.1) has a plurality of through-holes (6), and these through-holes (6) are spaced apart from each other, especially at regular intervals in the direction of the longitudinal axis (5).

4. The blocking element (1) according to claim 2 or 3, wherein the at least one through-hole (6) is circular, oval, or elliptical.

5. The blocking element (1) according to any one of claims 1 to 4, wherein the two side walls (2.2, 2.3) are formed to be mirror-symmetrical to each other.

6. The blocking element (1) according to any one of claims 1 to 5, wherein the two side walls (2.2, 2.3) have a substantially C-shaped or U-shaped cross-section, and the open side of the cross-section is directed towards the other side wall (2.2, 2.3) respectively.

7. The expandable material (3) includes a first expandable material (3.1) and a second expandable material (3.2), The blocking element (1) according to any one of claims 1 to 6, wherein the middle wall (2.1) of the carrier (2) is disposed between the first expandable material (3.1) and the second expandable material (3.2).

8. The cross-section of the first expandable material (3.1) perpendicular to the longitudinal axis (5) is smaller than the cross-section of the second expandable material (3.2) perpendicular to the longitudinal axis (5), the blocking element (1) according to any one of claims 1 to 7.

9. The first expandable material (3.1) and the second expandable material (3.2) are joined to each other via the at least one through-hole (6), the blocking element (1) according to any one of claims 2 to 8.

10. The blocking element (1) has at least two fixing elements (4) for fixing the blocking element (1) to the structural element, and / or at least one of the fixing elements (4) is formed as a barbed nail, the blocking element (1) according to any one of claims 1 to 9.

11. A method for manufacturing a blocking element (1) for blocking a structural element of a motor vehicle, the method comprising the following steps: Preparing a carrier (2) having a partition wall (2.1), a first side wall (2.2), and a second side wall (2.3), wherein these walls (2.1, 2.2, 2.3) of the carrier extend along a common longitudinal axis (5), the carrier (2) has an H-shaped cross-section in a plane perpendicular to the longitudinal axis (5), and in the H-shaped cross-section, the first side wall (2.2) and the second side wall (2.3) are each arranged at one end of the partition wall (2.1); Extruding a first expandable material (3.1) onto a first side of the partition wall (2.1) of the carrier (2); Extruding a second expandable material (3.2) onto a second side of the partition wall (2.1) of the carrier (2); A method comprising.

12. Performing the extrusion of the first expandable material (3.1) and the extrusion of the second expandable material (3.2) simultaneously in a co-extrusion process, the method according to claim 11.

13. Forming the carrier (2) by extrusion, and / or After forming the carrier (2), punching at least one through-hole (6) in the partition wall (2.1) of the carrier (2), the method according to claim 11 or 12.

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