Automotive engine or unit capsule completely surrounded by air cushion foil

Abstract

The object of the present invention is to completely surround an automobile engine or unit capsule with air cushion foil, thereby significantly influencing and adjusting the acoustic component characteristics.

Description

[Technical field]

[0001] The subject of the present invention is the complete surrounding of the engine or unit capsule of a motor vehicle with an air cushion foil, by means of which the acoustic component characteristics can be greatly influenced and adjusted. [Background technology]

[0002] Applications of air cushion foils are known, which primarily relate to the field of packaging. They are used here as insulating packaging, in particular for the storage, transport and dispatch of temperature-, heat- and cold-sensitive products as well as shock-sensitive products. See, for example, DE 20 2019 101 109 U1.

[0003] In this regard, US 2019 / 0375193 A1 discloses an insulating packaging material, typically made of a thermoplastic, such as a polyethylene (PE) air cushion foil laminated to a metallized polyester (PET) film, which has insulating properties due to the heat reflectivity of the metallized polyester and the air entrapment of the air cushion foil.

[0004] In addition to two- and three-ply PE air cushion foils, polypropylene (PP) air cushion foils are also known (EP 1 477 299 B1, DE 60 2004 007 185 T2).

[0005] Recyclable air cushion foils are also found.The biodegradable plastics are polylactic acid (PLA), polyhydroxyalkanoates (PHAs), in particular polyhydroxybutyrates (PHBs), blends of thermoplastic starch, or mixtures thereof and / or other biodegradable additives (DE 20 2009 014 881 U1), and also biodegradable aliphatic-aromatic copolyesters or blends of at least one biodegradable aliphatic-aromatic copolyester with polylactic acid or thermoplastic starch (DE 20 2010 008 483 U1).

[0006] Furthermore, self-adhesive (EP 1 621 330 B1) and textile (DE 20 2008 014 014 U1) air cushion foils are known.

[0007] In the literature, particularly relating to the automotive industry, it is described that hollow chambers or cushion-shaped foil packages (air cushions) are inserted into the foam insulation of floor panels and then allowed to re-expand (DE 35 31 886 C2).

[0008] It has also been proposed to fill the cushion with a gas that is lighter than air, for example helium (DE 79 29 637 U1).

[0009] However, in practice, no successful attempts have been made to insert a hollow chamber or a cushion-like foil package (air cushion) to induce foaming.

[0010] Of course, voids and air cushions are also found in other sound insulation materials, such as bulkheads, wheel arch liners, underside panels, etc. DE 10 2004 022 895 A1 discloses a clad part made of a thermoplastic material for shielding an engine and / or an exhaust system, which part has an at least partially hollow body. In the case of wheel arch liners, this is described in US 2018 / 0050731 A1 and US 10 131 383 B2. DE 100 22 902 A1 discloses voids in the roof lining of a motor vehicle with variable wall spacing.

[0011] Inflatable air cushions with active damping of elastic material between the sound-producing parts and the interior of the passenger compartment of a motor vehicle are described in DE 10 2004 037 767 B4 and in US 2008 / 0020199 A1.

[0012] DE 10 2005 003 994 B4 describes a method for producing sound absorbing material and various typical applications, among other things it states that the hollow chamber elements can be made with different dimensions in terms of height, diameter and width and that the hollow chamber elements can have different skin tensions or sags. Summary of the Invention [Problem to be solved by the invention]

[0013] The object of the present invention in comparison with the aforementioned prior art is therefore to provide a sound insulation material, in particular an engine and unit encapsulation, which, when used in an engine or unit encapsulation, provides for decoupling of the excitation of the carrier layer by the encapsulated component by arranging the air cushion foil between the carrier layer and the PUR foam, with an air cushion foil which withstands the process parameters required for the production of the sound insulation material and ensures a reliable bond and positioning with adjacent layers. [Means for solving the problem]

[0014] In a first embodiment, the subject of the invention is to provide a completely enclosed unit capsule 1 comprising: (a) The Shore (A) hardness is in the range of 60 to 95, the required thickness is in the range of 1.2 to 4 mm, and the density is in the range of 1.2 to 3.0 g / cm 3 Weight per unit area is 1.44~12g / m 2 a sound-absorbing carrier layer 2 made of a flexible compound of (b) Density in the range of 45-105 g / l, 20-250 kN / m 2 and a polyurethane (PUR) foam 3 having a storage modulus in the range of 0.3 to 0.8; (c) At least two layers of air cushion foil 4 of polyethylene terephthalate (PET), polyamide (PA) 6 or 6.6, partially or entirely between the carrier layer 2 and the PUR foam 3.

[0015] The use of air cushions in the field of engine or unit capsules is not known from the state of the art, especially in the automotive industry.

[0016] On the one hand, no material for the air cushion foil is mentioned at all, on the other hand, only PE is mentioned, and there is no mention of adhering PUR foam to the air cushion foil, since PUR foam does not adhere to PE, for example.

[0017] Furthermore, there is no mention of positioning / fixing in multi-layer composites and the associated manufacturing technology of the sound insulation components. Precisely here, the focus is on the foil material according to the invention due to the necessary process parameters (temperature, pressure...) in the thermoforming and backforming processes.

[0018] The carrier layer 2 can be manufactured in various ways. Particularly preferred within the context of the present invention is the injection moulding of the carrier layer 2, which provides a contour-to-contour and surface-weight optimised design, while ensuring reproducibility. The sound-insulating carrier layer 2 can therefore be produced with a thickness in the range of 1.2-4 mm and a weight of 1.2-3.0 g / cm. 3 resulting in a weight per unit area of ​​1.44 to 12 kg / m 2 Within the ranges of density, thickness and weight per unit area mentioned above, these parameters can be varied locally as required.

[0019] Furthermore, the PUR foam 3 can be bonded to the air cushion foil 4 in any manner. In the sense of the present invention, it is particularly preferred to back-foam the PUR foam 3. For this purpose, the pre-product consisting of the carrier layer 2 and the air cushion foil 4 is placed in a suitable contoured mold and back-foamed with the foam raw material in a manner known per se.

[0020] Particularly preferably, the PUR foam 3 has a density in the range of 55 to 85 g / l and / or a compressibility of 40 to 100 kN / m 2and / or a loss factor of 0.33 to 0.50. Thus, the spring softness and its (PUR foam 3) viscoelasticity are guaranteed.

[0021] Air cushion foils 4 are commercially available in a variety of specifications. In particular, air cushion foils 4 are distinguished into two-ply and three-ply. They usually consist of two layers of welded thermoplastic, rarely thermosetting materials, with a smooth cover film and a second layer in which mainly round air cushions are built in at regular intervals by nub cylinders and vacuum rollers, which are known to play a role in absorbing shock. The three-ply structure is more elastic due to the presence of the second layer of smooth cover film. According to Wikipedia (keyword: air cushion foil, searched in March 2020), the nub diameter of the small nub film is about 10 mm, and the nub diameter of the large nub film is about 25 mm. According to the present invention, air cushion foils with a nub diameter in the range of 2 to 20 mm and a cylinder height (nub height) in the range of 1 to 15 mm are particularly preferred.

[0022] The air cushion foil 4 can fill the entire installation space between the carrier layer 2 and the PUR foam 3, all around the outer periphery. However, according to the invention the air cushion foil 4 is cut to size before insertion, so that it has the same shape / contour on the surface and / or is arranged according to requirements.

[0023] Likewise, according to the invention it is also possible for the air cushion foils 4 to be arranged in the same shape / contour and / or according to requirements as the individual air cushions on the surface, in particular the diameter and / or height of the nub cylinders are varied over the surface of the air cushion foil.

[0024] Further possible variations depending on the application of the air cushion foil 4 lie in different fillings of the nub cylinders. For example, it is preferred according to the invention to fill the individual air cushions of the air cushion foil 4 with air, nitrogen or (noble) gases.

[0025] Alternatively or cumulatively, according to the invention, the individual air cushions of the air cushion foil 4 are fibres, in particular plastic, vegetable, animal and / or mineral fibres; Foam flakes, in particular polyurethane foam flakes, polyester foam flakes and / or polyolefin foam flakes; down; Hollow bodies, in particular polyolefins, ceramics, glass, EPS, EPP and / or PEPP; Wood chips; wood flour, It is also possible to use as a single material and / or as a mixture of two or more materials to fill partially or completely.

[0026] Particularly preferably, each of the air cushion foils 4 has a foil thickness within the range of 20 to 500 μm.

[0027] In a further embodiment of the invention, the air cushion foil 4 consists on its upper and / or lower side of a nonwoven film made of PA+PET fibers, PET+PET fibers and / or PE+PET fibers, in which case the bonding of the further layers is resolved more efficiently and stably.

[0028] It is also possible, however, to glue or weld the air cushion foil 4 onto the carrier layer 2. However, this means that the air cushion foil 4 is either self-adhesive (expensive) or has to be glued by an additional adhesive in a further step (expensive, cycle time). With known fastening methods such as gluing, welding, etc., additional steps are required, which significantly increase the production costs of the capsules. Therefore, the air cushion foil 4 preferably has openings 5 ​​for fastening to the carrier layer 2 according to the invention. In this way, the PUR foam 3 adequately fastens the air cushion foil 4 to the carrier layer 2 without further processing steps or devices per se.

[0029] The core of the present invention is therefore to provide an acoustically and thermally effective, completely enclosed engine or unit encapsulation 1, which is of weight per unit area, possibly of different design, in relation to the requirements on the carrier layer surface, combining in particular hydrolysis-resistant, viscoelastic PUR foam and sound-insulating encapsulation elements, in particular a multilayer air cushion foil made of PA6 or PA6.6, arranged between the carrier layer 2 and the PUR foam 3, as appropriate, with the shape / contour of individual air cushions (nubs) - the same and / or different on the surface - partially or over the entire surface.

[0030] The advantages of the present invention lie in particular in the combination of the carrier layer 2 with integrated overlap and closure mechanism and the foam system 3, where the carrier layer 2 can have the required weight per unit area and the foam system is acoustically very effective and is especially resistant to hydrolysis. Openings for cables etc. in the fully enclosed capsule 1, due to the (form-fitted) edge / overlap design of the capsule element / shell as well as the arrangement of a multi-layer air cushion foil 4, in particular made of PA6 or PA6.6, between the carrier layer 2 and the PUR foam 3, provide a decoupling of the excitation of the carrier layer 2 by the encapsulated components and do not present acoustic leak points. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 shows a unit capsule with an air cushion foil placed between a PUR foam and an injection molded carrier layer. [Diagram 2] FIG. 1 is a detailed illustration of a two-layer PA6-based air cushion foil. [Diagram 3] 1 is a graph showing the difference in acoustic efficiency of a capsule without and with an air cushion foil. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] A self-blended PP-based compound consisting essentially of TPE / PP and mineral fillers was used to produce a material with a weight per unit area of ​​5 kg / m2 by injection molding. 2 Thus, a carrier layer 2 was produced having a uniform Shore (A) hardness of 78 over the entire surface.

[0033] After the injection-molded carrier layer 2 is inserted into the foaming mold, a commercially available PA6-based air cushion foil 4 (total thickness 3 mm, nub cylinder diameter 10 mm, with punched holes 5 for positioning the carrier layer 2) is placed on top, and this is then mixed with a commercially available soft adhesive PUR foam 3, density 80 g / l, storage modulus 90 kN / m 2 The back side was foamed with a loss factor of 0.4.

[0034] After this capsule was attached around the automobile unit as shown in Figure 1, the airborne sound dB(A) was measured on a test stand.

[0035] Figure 1 shows a unit capsule 1 with an air cushion foil 4 disposed between a PUR cold foam 3 and an injection moulded carrier layer 2. The two layers of PA6 based air cushion foil 4 are explained in more detail in figure 2.

[0036] Figure 3 clearly shows the difference in acoustic efficiency between the capsule without and with the air cushion foil 4. In particular, in the important mid-frequency band between 300 and 800 Hz, the level is reduced by about 6 dB.

Claims

1. A completely enclosed automobile engine or automobile unit capsule, comprising: (a) Shore hardness in the range of 60 to 95, thickness in the range of 1.2 to 4 mm, and density in the range of 1.2 to 3.0 g / cm 3 Weight per unit area is 1.44 to 12 kg / m 2 a carrier layer, (b) a density in the range of 45 to 105 g / l, 20 to 250 kN / m 2 and a loss factor of 0.3 to 0.8; (c) having at least two layers of air cushion foil made of polyethylene terephthalate (PET), polyamide (PA) 6 or 6.6 partially or completely between the carrier layer and the PUR foam; Automotive engine or automotive unit capsule.

2. 2. An engine or unit capsule according to claim 1, characterised in that the carrier layer is injection moulded.

3. 3. Engine or unit capsule according to claim 1 or 2, characterized in that the thickness and density of the carrier layer vary in each case depending on requirements.

4. 4. An engine or unit capsule according to claim 1, wherein the PUR foam is back-foamed.

5. The PUR foam has a density in the range of 55 to 85 g / l and / or a stiffness of 40 to 100 kN / m 2 An engine or unit capsule according to any one of claims 1 to 4, characterized in that it has a storage modulus in the range of 0.49 to 0.50 and / or a loss factor of 0.33 to 0.

50.

6. An engine or unit capsule according to any one of claims 1 to 5, characterized in that the air cushion foil has a three-layer structure.

7. An engine or unit capsule according to any one of claims 1 to 6, characterised in that the shape / profile of the air cushion foil is uniformly distributed over the surface.

8. An engine or unit capsule according to any one of claims 1 to 7, characterised in that the air cushion foils are arranged in the same shape / contour as individual air cushions on the surface.

9. Engine or unit capsule according to any one of the preceding claims, characterised in that the individual air cushions of the air cushion foils are filled with air, nitrogen or a (noble) gas.

10. The individual air cushions of the air cushion foil are Fibers selected from the group consisting of plastic fibers, vegetable fibers, animal fibers and inorganic fibers; a foam flake selected from the group consisting of polyurethane foam flake, polyester foam flake and polyolefin foam flake; down, Hollow bodies selected from the group consisting of polyolefins, ceramics, glass, EPS, EPP and PEPP, or Wood chips or wood flour, An engine or unit capsule according to any one of claims 1 to 9, characterized in that it is partially or completely filled with as a single material or as a mixture of two or more materials.

11. 11. Engine or unit capsule according to claim 1, characterized in that the air cushion foil comprises on its upper and / or lower side a film fleece made of PA+PET fibres, PET+PET fibres and / or PE+PET fibres.

12. An engine or unit encapsulation according to any one of claims 1 to 11, characterised in that the air cushion foil has openings for fastening to the carrier layer.

13. An engine or unit capsule according to any one of claims 1 to 12, characterised in that the individual nubs of the air cushion foil have the same or different shapes / contours in surface dimensions.

14. An engine or unit capsule according to any one of the preceding claims, characterized in that the individual foils of the air cushion foil have a foil thickness in the range of 20 to 500 μm.

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