Sound insulation element for the front wall of a vehicle body and support element for such a sound insulation element.

Description

[0001] The invention relates to a sound insulation element for the front wall of a vehicle body that separates the passenger compartment from the engine compartment. The invention further relates to a support element for a sound insulation element for arrangement on the front wall of a vehicle body.

[0002] It is generally known to install a sound insulation element on the inside of the bulkhead of a vehicle body, i.e., on the inside of the wall between the passenger compartment and the engine compartment. Examples of such bulkhead insulation can be found in WO-A-2018 / 192858, US-A-2006 / 0091699, or DE-A-37 33 284.

[0003] US Patent 2007 / 218790 discloses a sound insulation element for the front wall of a vehicle body located between the passenger compartment and the engine compartment, comprising a composite component that has a plastic carrier layer and a sound-absorbing layer connected thereto, wherein the composite component has a front surface formed by the outer surface of the plastic carrier layer when viewed in its installed state, facing the passenger compartment, and at least one first through-opening in the composite component, wherein the first through-opening has a carrier layer hole formed in the plastic carrier layer with a hole edge.

[0004] These sound insulation elements have a sandwich construction, consisting of a plastic carrier layer (also known as a heavy layer) and a sound-absorbing layer molded onto the plastic carrier layer, made of sound-absorbing material, particularly polyurethane foam. The front bulkhead of the vehicle body has several openings for cables, pipes, or components. Accordingly, the sound insulation element also has openings that typically align with these openings in the bulkhead. Depending on the type of component passing through the sound insulation element and the bulkhead, it is necessary to protect it from mechanical damage (abrasion protection). One possible way to achieve this protection is to surround the edge of a opening in the sound insulation element with foam or the sound-absorbing material.

[0005] The sound-absorbing material is typically molded onto the plastic carrier layer in a specially designed mold (usually a foaming mold) into which the plastic carrier layer is placed. The plastic carrier layer is previously manufactured in a separate mold. In the area where the edges of the holes in the plastic carrier layer are at least partially embedded with sound-absorbing material, the material must be able to penetrate at least partially into the hole in the carrier layer. Ideally, the sound-absorbing material should partially surround the edge of the hole on both sides of the plastic carrier layer. In both cases, this can cause the plastic carrier layer to "float" within the mold during the manufacturing process, leading to unsatisfactory results.To avoid this, the corresponding molds for forming the sound-absorbing material onto the plastic substrate have retaining pins that hold the plastic substrate down along the edge of a hole that is to be at least partially enclosed by the sound-absorbing material. Such mold retaining pins increase the manufacturing costs of the mold and complicate the cleaning process, which is generally necessary for such molds from time to time. Furthermore, the sound-absorbing layer formed with such a mold has cavities caused by the retaining pins, which is acoustically disadvantageous.

[0006] From DE-A-10 2013 006 300, it is known to position a core of a device handle, surrounded by plastic, centrally in a mold by means of spacer pins projecting from the core on all sides. This method is not suitable for such 2K components where one plastic component is only to be coated with the second plastic component on one side.

[0007] From DE-C-198 33 098 a method for manufacturing a padded object with a core and a padded cover surrounding it on all sides is known.

[0008] The object of the invention is to create a sound insulation element for the front wall of a vehicle body arranged between the passenger compartment and the engine compartment, as well as a support element for such a sound insulation element, with the help of which the effort required on the part of the tool to maintain the position of the support element in the molding tool for forming sound-absorbing material onto the support element can be reduced.

[0009] To solve this problem, the invention proposes a sound insulation element for the front wall of a vehicle body arranged between the passenger compartment and the engine compartment, wherein the sound insulation element is provided with a composite component comprising a plastic carrier layer and a sound-absorbing layer connected thereto, wherein the composite component, when viewed in its installed state, has a front side facing the passenger compartment formed by the outside of the plastic carrier layer and a rear side abutting the front wall formed by the outside of the sound-absorbing layer facing away from the plastic carrier layer, and at least one first through-opening in the composite component,wherein the first through-opening has a hole in the plastic carrier layer with a hole rim and a hole in the sound-absorbing layer with a hole rim formed in the sound-absorbing layer, and wherein at least one retaining projection projects from the plastic carrier layer on the inside surface of the plastic carrier layer facing away from the outside surface of the plastic carrier layer and thus facing the sound-absorbing layer, the retaining projection being embedded in the sound-absorbing material of the sound-absorbing layer and the free ends of which face away from the plastic carrier layer being substantially flush with the outside surface of the sound-absorbing layer facing away from the plastic carrier layer.

[0010] The invention essentially provides for the use of a retaining projection that is part of the plastic carrier layer, i.e., part of the carrier element of the sound insulation element to which the sound-absorbing material is molded, instead of a retaining projection arranged on the molding tool. Such a retaining projection is located at the edge of a hole or offset outwards from the edge of a perforation, i.e., a hole in the plastic carrier layer, which, together with a corresponding hole in the sound-absorbing layer, forms a passage for the sound insulation element.

[0011] In the sound insulation element according to the invention, the at least one retaining projection, which can be, for example, pin-shaped or dome-shaped, is embedded in the sound-absorbing material of the sound-absorbing layer. Advantageously, several such retaining projections exist around the perimeter of a hole in the carrier layer. Unlike the prior art, in which the retaining projections (retaining pins) are part of one of the mold components for forming the sound-absorbing material onto the plastic carrier layer, in the sound insulation element according to the invention, no cavities exist in the sound-absorbing layer after demolding from the mold; rather, the retaining projections of the plastic carrier layer extend into the sound-absorbing layer and, if necessary, through it.

[0012] The sound insulation element according to the invention, as already described above, is designed as a composite component and comprises a plastic carrier layer (so-called heavy layer) and a sound-absorbing layer made of sound-absorbing material (e.g., PU foam). The composite component, thus constructed in two layers, has two outer surfaces, one formed by the plastic carrier layer and the other by the sound-absorbing layer. The inner surfaces of both layers are in contact with each other; the two layers are bonded together at these inner surfaces. In the installed state, the outer surface of the plastic carrier layer faces the passenger compartment; this side of the composite component forms the front, while the rear of the composite component is formed by the outer surface of the sound-absorbing layer that rests against the front wall.

[0013] From the inside of the plastic carrier layer, at least one retaining projection protrudes in the area of ​​a hole in the carrier layer, the free end of which faces away from the back of the plastic carrier layer is essentially flush with the outside of the sound-absorbing layer, in that the free end does not protrude beyond the outside of the sound-absorbing layer but is rather preferably covered by a comparatively thin layer (e.g. at least 1 mm and at most 5 mm) of sound-absorbing material.

[0014] As previously mentioned, it is advantageous to provide several retaining projections around the perimeter of a hole, which are then expediently designed in the form of pins or domes. The design of the retaining projections, or of the at least one retaining projection, should be chosen such that, in the mold used to form the sound-absorbing material onto the plastic carrier layer, this sound-absorbing material can flow around and over the at least one retaining projection. If, in an advantageous embodiment of the invention, a collar that at least partially surrounds the carrier layer hole is used as a retaining projection, it should have recesses in its circumferential wall or edge recesses open towards the upper edge. With such a design of the collar, the sound-absorbing material introduced into the mold can flow through it.

[0015] The sound insulation element described above is designed in particular for forming hole edges in the plastic carrier layer that are provided with sound-absorbing material. The sound-absorbing material has a projection extending into the hole in the carrier layer, which is flush with the outer surface of the plastic carrier layer or projects forward, thus encompassing the hole edge on both sides. To prevent unwanted shearing of the sound-absorbing material in the hole edge area, interlocking structures can be provided between the plastic carrier layer and the sound-absorbing layer by means of anchoring projections, perforations, or the like formed by the sound-absorbing material. Examples of penetrations in the plastic carrier layer filled with sound-absorbing material in the area of ​​penetrations of the sound insulation element can be found in DE-A-41 32 571, EP-A-2 786 851 and JP H07-285 138 A.

[0016] Individual embodiments of the invention are the subject of the dependent claims.

[0017] In an advantageous further development of the invention, it is provided that sound-absorbing material of the sound-absorbing layer protrudes inwards over the edge of the hole of the carrier layer into the first hole and forms an annular protrusion edge.

[0018] In this embodiment, it can further be advantageously provided that the protruding edge is flush with the outer surface of the plastic carrier layer or extends along at least a portion of the hole edge of the carrier layer hole on the outer surface of the plastic carrier layer. The sound insulation element according to the invention can also advantageously be provided with at least one second through-opening in the composite component, comprising a carrier layer hole formed in the plastic carrier layer and a sound-absorbing layer hole formed in the sound-absorbing layer, wherein both holes have flush hole edges.

[0019] In addition to the sound insulation element described above according to the invention, the above-mentioned problem can also be solved according to the invention by a support element for a sound insulation composite component for arrangement on an end wall of a vehicle body provided between the engine compartment and the passenger compartment, wherein the support element is provided with a plastic carrier layer with an outer side and an inner side, onto which sound-absorbing material of a sound-absorbing layer of the sound insulation composite component can be applied or attached in a mold having at least two mold parts, at least one first carrier layer hole formed in the plastic carrier layer with a hole edge and at least one retaining projection arranged on and / or offset to the hole edge, projecting from the plastic carrier layer, which protrudes from the inner side of the plastic carrier layer,wherein the plastic carrier layer can be inserted into the mold with its outer surface in contact with a first mold part, and the end of the at least one retaining projection facing away from the inner surface of the plastic carrier layer is provided for contacting a second mold part to hold the plastic carrier layer in contact with the first mold part in the area of ​​the hole edge of the first carrier layer hole.

[0020] In order to realize a hole edge of the plastic carrier layer provided with sound insulation material in such a carrier element, it is possible, for example, that the first hole of the plastic carrier layer is provided for penetration with radial clearance to the hole edge of the first carrier layer hole by means of a molding tool core, in particular by means of a molding tool core which is arranged on the first or the second molding tool part of the molding tool provided for molding the sound damping material onto the back of the plastic carrier layer.

[0021] The support element can advantageously be designed with retaining projection structures, as previously described in connection with the sound insulation element. The plastic support layer of the support element can also be designed as described above in connection with the invention. In particular, the plastic support layer of the support element can be provided with sound insulation material and the sound-absorbing layer, as provided above within the scope of the invention.

[0022] The invention is explained in more detail below using an exemplary embodiment and with reference to the drawings. In detail: Fig. 1 shows a perspective and exploded view of a vehicle body with a front wall sound insulation element; Fig. 2 shows a perspective view of the design of the heavy layer, i.e., the plastic carrier layer of the sound insulation element according to Fig. 1, Fig. 3 a section through the mold for molding sound insulation material onto the plastic carrier layer according to Fig. 2 , wherein this is inserted into the mold, Fig. 4 shows a section through the mold accordingly Fig. 3 However, after the sound-absorbing material has been inserted, Fig. 5 shows a view of the back of the sound insulation element in the installed state, resting against the front wall of the vehicle body, Fig. 6 shows a perspective view of the sound insulation element from the back, and Fig. 7 shows a section through the sound insulation element along line VII-VII. Fig. 6 and Fig. 8 shows an alternative design of a hold-down projection in perspective.

[0023] Fig. 1Figure 1 schematically shows a vehicle body 10 with a front wall 12, to which a sound insulation element 14, designed as a composite component, is attached. The sound insulation element 14 is fixed to the front wall 12 at least partially by means of, for example, fixing projections (not shown) formed integrally with the sound insulation element 14, which, in the mounted state of the sound insulation element 14, interact with receiving openings in the vehicle body 10 and in the front wall 12, respectively, in which the fixing projections are positioned. In this context, reference is made, by way of example, to WO-A-2018 / 192858, the contents of which are hereby incorporated by reference into the subject matter of the present disclosure.

[0024] As is known per se, the sound insulation element 14 has a so-called mass-spring system, comprising a plastic carrier layer 16 as a heavy or mass layer made of, for example, EVA / PE, PE, PP, EPDM, TPE, TPO and / or polyurethane foam, each containing a high weight fraction of up to 70 wt.% of a high-density mineral filler, for example, feldspar, and a sound-absorbing layer 18 (see, for example, Fig. 6 ) made of a sound-absorbing material (for example, polyurethane foam).

[0025] In the installed state according to Fig. 1The sound insulation element 14 has a front face 20 facing the passenger compartment and a rear face 22 facing and abutting the front wall. The front face 20 is formed by the outer surface 24 of the plastic carrier layer 16, while the rear face 22 is formed by the outer surface 26 of the sound-absorbing layer 18. The plastic carrier layer 16 and the sound-absorbing layer 18 are connected to each other at their mutually facing inner surfaces 28, 30 (see also Fig. 7 ).

[0026] The sound insulation element 14 has several through-openings 32, 34, 36, 38, which are configured differently in this embodiment and represent different types of penetrations for a sound insulation element. With the exception of through-opening 34, the other through-openings 34 shown in the figures are provided with sound-absorbing material along the edges of holes in the plastic carrier layer 16. The formation of the sound-absorbing material along these hole edges requires a certain amount of positioning aid within the mold provided for forming the sound-absorbing material, as shown in the Fig. 3 and 4 shown.

[0027] In Fig. 3Figure 40 shows a cross-section through a two-part mold 40 in this embodiment, comprising a first mold part 42 and a second mold part 44. The previously produced plastic carrier layer 16 is first inserted into the mold cavity 46 of the mold 40, with its outer surface 24 resting on the inside of the first mold part 42. The mold 40 is then closed. In this embodiment, the plastic carrier layer 16 has four holes 48, 50, 52, 54 with hole edges 49, 51, 53, 55. A mold core 56 projects into hole 54, completely filling it. The holes 48, 50, 52 each contain mold tool cores 58, 60, 62, which are smaller in cross-section than the holes and thus leave spaces 64, 66, 68 in the mold space 46 between themselves and the hole edges 49, 51, 53.

[0028] The open spaces are therefore, as shown by the Fig. 3 and 4 It can be seen that the mold is filled with sound-absorbing material when this material is introduced into the mold 40 via, for example, one (or, in particular, several) inlets 70. The mold cores 56, 58, 60, 62 ensure that the holes 57, 59, 61, 63 in the sound-absorbing layer 18 of the sound insulation element 14 are aligned with the holes 48, 50, 52, 54 in the carrier layer.

[0029] The ingress of sound-absorbing material into the holes 48, 50, 52 (no material penetrates hole 54 because the mold core 56 completely fills this hole) poses the risk that the plastic support layer 16 will be undermined and then float to the surface in the mold cavity 46. To prevent this, retaining projections 72 (in this embodiment, all in the form of pins or domes) are arranged in the area of ​​each hole 48, 50, 52, extending from the inner surface 28 of the plastic support layer 16. These projections bear against the inner surface 74 of the second mold part 44, which defines the mold cavity 46, or their free ends 76 are arranged at a short distance from the mold part 44. These retaining projections 72 hold the plastic carrier layer 16 positioned on the inside 78 of the first mold tool part 42.This prevents the plastic carrier layer 16 from "floating" when the sound-absorbing material penetrates and flows around the edges of the holes 48, 50, 52.

[0030] Depending on the desired design of the enclosing, surrounding, or partially surrounding of the edges of holes 48, 50, 52 with sound-absorbing material, the plastic carrier layer 16 has different structures in the area of ​​said holes, as shown in the Fig. 3 and 4as shown in Figures 6 and 7. For example, the overhanging edge 80 in hole 48 is flush with the outer surface 24 of the plastic carrier layer 16, while the corresponding overhanging edge 82, 84 of holes 50, 52 surrounds the hole edges 51, 53 on both sides. Furthermore, with regard to the design of hole 52, it is provided that additional hook structures or similar projections 86 protrude from the front 20 of the plastic carrier layer 16, which are embedded in the sound-absorbing material and thus provide additional support for the sound-absorbing layer 18 on the front 20 of the plastic carrier layer 16.

[0031] In Fig. 8An alternative embodiment of a retaining projection 88 is shown. In this embodiment, the retaining projection 88 is designed as a circumferential collar 90 that extends around the opening in the plastic carrier layer indicated at 92. The collar 90 has perforations 94 through which sound insulation material can pass to near the edge of the hole in the plastic carrier layer 92 or around its edge, as is the case for the hole designs according to Fig. 3 As shown. In the state provided with sound insulation material, the retaining projection 88 is embedded in this material. LIST OF REFERENCE SYMBOLS

[0032] 10 Vehicle body 12 Front wall 14 Sound insulation element 16 Plastic carrier layer 18 Sound-absorbing layer 20 Front 22 Back 24 Outer surface front 26 Outer 28 Inner 30 Inner 32 Through opening 34 Through opening 36 Through opening 38 Through opening 40 Two-part mold 42 First mold part 44 Second mold part 46 Mold chamber 48 Carrier layer hole 49 Hole edge 50 Carrier layer hole 51 Hole edge 52 Carrier layer hole 53 Hole edge 54 Carrier layer hole 55 Hole edge 56 Mold core 57 Sound-absorbing layer hole 58 Mold core 59 Sound-absorbing layer hole 60 Mold core 61 Sound-absorbing layer hole 62 Mold core 63 Sound-absorbing layer hole 64 Clearance 66 Clearance 68 Clearance 70 Inlet 72 Hold-down projection 74 Inside of mold cavity 76 Free end of hold-down projection 78 Inside of mold cavity 80 Overhang 82 Overhang 84 Overhang 86 Projection 88 Hold-down projection 90 Collar 92 Plastic carrier layer 94 Opening in collar BIBLIOGRAPHY

[0033] WO-A-2018 / 192858 US-A-2006 / 0091699 DE-A-37 33 284 DE-A-10 2013 006 300 DE-C-198 33 098 DE-A-41 32 571 EP-A-2 786 851 JP H07-285 138 A

Claims

1. Sound insulation element for the end wall of a vehicle body arranged between the passenger compartment and the engine compartment, with - a composite component comprising a plastic carrier layer (16) and a sound-absorbing layer (18) connected thereto, - wherein the composite component has a front side (20) facing the passenger compartment when viewed in its installed state and formed by the outer surface (24) of the plastic carrier layer (16), and a rear side (22) which bears against the end wall and is formed by the outer side (26) of the sound-absorbing layer (18) facing away from the plastic carrier layer (16) and - at least one first through opening (32, 34, 36, 38) in the composite component, - wherein the first through hole (32, 34, 36, 38) comprises a carrier layer hole (48, 50, 52, 54) formed in the plastic carrier layer (16) with a hole edge (49, 51, 53, 55) and a sound-absorbing layer hole (57, 59, 61, 63) formed in the sound-absorbing layer (18) with a hole edge and - wherein at least one hold-down projection (72) projects from the plastic carrier layer (16) on the inner side (28) of the plastic carrier layer (16) facing away from the outer surface (24) of the plastic carrier layer (16) and thus facing the sound-absorbing layer (18) at the and / or offset to the hole edge (49, 51, 53, 55) of the carrier layer hole (48, 50, 52, 54), which is embedded in the sound-absorbing material of the sound-absorbing layer (18) and whose free ends (76) facing away from the plastic carrier layer (16) are substantially aligned with the outer side (26) of the sound-absorbing layer (18) facing away from the plastic carrier layer (16).

2. Sound-insulating element according to claim 1, characterized in that the free end (76) of the at least one hold-down projection (72) facing away from the inner side (28) of the plastic carrier layer (16) is covered with sound-absorbing material.

3. Sound insulation element according to claim 1 or 2, characterized in that several hold-down projections (72) are arranged circumferentially around the carrier layer hole (48, 50, 52, 54).

4. Sound-insulating element according to one of claims 1 to 3, characterized in that the at least one hold-down projection (72) is designed as a pin-shaped projection or as a hold-down dome.

5. Sound insulation element according to claim 1 or 2, characterized in that the at least one hold-down projection (72) is designed as a collar running around the carrier layer hole (48, 50, 52, 54) and having a circumferential wall provided with perforations.

6. Sound-insulating element according to one of claims 1 to 5, characterized in that sound-absorbing material of the sound-absorbing layer (18) projects inwards beyond the edge (49, 51, 53, 55) of the hole in the carrier layer hole (48, 50, 52, 54) and forms an annular projection edge (80, 82, 84).

7. Sound insulation element according to claim 6, characterized in that the projection edge (80, 82, 84) is aligned with the outer side (24) of the plastic carrier layer (16) or extends along at least a partial region of the perforated edge (49, 51, 53, 55) of the carrier layer hole (48, 50, 52, 54) on the outer side (24) of the plastic carrier layer (16).

8. A sound insulation element according to any one of claims 1 to 7, characterized by at least one second through hole (32, 34, 36, 38) in the composite component, comprising a support layer hole (48, 50, 52, 54) formed in the plastic carrier layer (16) and a sound-absorbing layer hole (57, 59, 61, 63) formed in the sound-absorbing layer (18), both holes having aligned hole edges.

9. Carrier element for a sound insulation element according to claim 1 for arrangement on an end wall of a vehicle body provided between the engine compartment and the passenger compartment, with - a plastic carrier layer (16) with an outer side and with an inner side, to which sound-absorbing material of a sound-absorbing layer (18) of the sound-insulating composite component can be applied in a molding tool having at least two molding tool parts, - at least one first carrier layer hole formed in the plastic carrier layer (16) with a hole edge and - at least one hold-down projection (72) which is arranged on and / or offset relative to the edge of the hole, projects from the plastic carrier layer (16) and protrudes from the inside of the plastic carrier layer (16), the end of the at least one hold-down projection (72) facing away from the inside of the plastic carrier layer (16) being suitable and intended for contacting a second mold part for holding the plastic carrier layer (16) against a first mold part in the region of the edge of the hole of the first carrier layer hole.

10. Carrier element according to claim 9, characterized in that the first hole of the plastic carrier layer (16) is provided for penetration with radial clearance to the hole edge of the first carrier layer hole by a moulding tool core, in particular by a moulding tool core, which is arranged on the first or the second moulding tool part of the moulding tool provided for moulding the sound-absorbing material to the rear side of the plastic support layer (16).

11. Carrier element according to claim 9 or 10, characterized in that the at least one hold-down projection (72) is designed as specified in one of claims 1 to 8 and / or in that the plastic carrier layer (16) is designed as specified in one of claims 1 to 8 and / or in that the plastic carrier layer (16) is provided with a sound-absorbing layer (18) or with sound-absorbing material as specified in one of claims 1 to 8.