ENGINE COVER ARRANGEMENT

Abstract

The present invention is directed to a cover arrangement for reducing the noise emitted by a motor vehicle part, in particular of the engine of a motor vehicle, comprising a cover having at least a fibrous carrier layer, and the cover arrangement comprising at least one mounting part for mounting the cover to the vehicle, the mounting part having at least one base portion made from a thermoplast, characterized in that the at least one mounting part is mounted to the cover by at least one welding connection of the at least one base portion and at least one fibrous carrier layer.

Claims

1. A cover arrangement for reducing the noise emitted by a motor vehicle part, in particular of the engine of a motor vehicle, comprising a cover having at least a fibrous carrier layer and the cover arrangement comprising at least one mounting part for mounting the cover to the vehicle, the mounting part having at least one base portion made from a thermoplast, characterized in that the at least one mounting part is mounted to the cover by multiple welding connections, of the at least one base portion and at least one fibrous carrier layer and wherein at least a part of the base portion contact the outer surface of the fibrous carrier layer and penetrates the fibrous carrier layer at least a part, and the welding connection is localized within said fibrous carrier layer at least in part.

2. The cover arrangement according to claim 1, wherein the fibrous carrier layer has an area weight between 200 and 1700 g/m.sup.2, preferably between 400 and 1500 g/m.sup.2.

3. The cover arrangement according claim 1, wherein at least a part of the base portion contact the outer surface of the fibrous carrier layer and or penetrates the fibrous carrier layer at least in part and extending into the at least one fibrous carrier layer, wherein the thermoplast material of the base portion is substantially hollow-cylindrical shaped and having a diameter of substantially 1.0 mm to 5.0 mm.

4. The cover arrangement according to claim 1, wherein the cover further comprises at least one additional layer in the form of a light foam and or a film layer and or a nonwoven covering layer, superposed and laminated to the fibrous carrier layer on the surface at least in the area where the welding connection is localised, and wherein at least part of the base portion penetrates the additional layer or layers, contacts the outer surface of the fibrous carrier layer and or penetrates the fibrous carrier layer (3; 3) at least in part, and, in particular, the welding connection is localized within said fibrous carrier layer at least in part.

5. The cover arrangement according to claim 1, wherein the thermoplast of the base portion is chosen from the group of materials comprising polyamide, in particular polyamide 6.6, polyamide 6, polyesters, in particularly polyethylene terephthalate or polybutylene terephthalate and wherein the thermoplast may or may not contain filler, e.g. a glass fiber or mineral fiber.

6. The cover arrangement according claim 1 wherein the at least one fibrous carrier layer is a consolidated fibrous material consisting of fibres and a binder in the form of a thermoplastic binder or a thermoset binder whereby the binder forms small binding points between the fibers to consolidate the fibrous material.

7. The cover arrangement according to claim 6, whereby the fibres are at least one of thermoplastic fibers, preferably polyester fibers, preferably polyethylene-terephthalate (PET) or polybutylene terephthalate (PBT), natural fibers, preferably cotton or flax fibers, or mineral fibers, preferably glass fibers, carbon, ceramic or basalt fibers or a mixture of such fibers.

8. The cover arrangement according to claim 1, wherein the cover arrangement is configured to be an engine top cover arrangement for being mounted atop the engine of a motor vehicle.

9. The cover arrangement according to claim 1, wherein at least a part of the base portion penetrates the fibrous carrier layer partly, and wherein the welding connection is localized within said fibrous carrier layer such that the area of the cover, which is located above the location of the welding connection, is substantially unaffected by the process step of welding the base portion to the fibrous carrier layer, in particular remaining substantially plain and visually unimpaired.

10. The cover arrangement according to claim 4, wherein the thickness of the at least one light foam layer is between 0.5 mm and 5.0 mm, the thickness of the fibrous carrier layer is between 0.5 mm and 5.0 mm, the thermoplast material of the base portion is penetrating the at least one light foam layer and extending into the at least one fibrous carrier layer, wherein the thermoplast material of the base portion is substantially hollow-cylindrical shaped and having a diameter of substantially 1.0 mm to 5.0 mm.

11. A method for connecting at least one mounting part with a cover, the mounting part being configured for mounting the cover to a vehicle, in particular the cover being an engine top cover for covering the engine of the vehicle from above, the cover having superposed layers, including at least a fibrous carrier layer and at least one additional layer or layers, like a light foam layer and or a film layer and or a nonwoven covering layer, the at least one mounting part having at least one base portion made from a thermoplast, comprising mounting the at least one mounting part to the cover by generating at least one welding connection by ultrasonic welding, of the at least one base portion and at the fibrous carrier layer.

12. The method according to claim 11, wherein the step of mounting the at least one mounting part to the cover comprises the steps of: penetrating the additional layer or layers by at least a part of at least one base portion; at least partly penetrating the fibrous carrier layer by said part of the base portion realizing the welding connection at least partly within said at least one fibrous carrier layer.

13. The method according to claim 11, wherein the step of mounting the at least one mounting part to the cover comprises the steps of: pressing a ultrasonic welding head of an ultrasonic welding machine against a base portion of a mounting part, thereby melting and displacing some thermoplast material of the base portion towards the at least one fibrous carrier layer, preferably: then penetrating the light foam layer and or film layer and or nonwoven layer by the thermoplast material using the ultrasonic welding head, and then penetrating the at least fibrous carrier layer at least in part by the thermoplast material using the ultrasonic welding head and forming the welding connection between the thermoplast material with the at least one fibrous carrier layer using the ultrasonic welding head.

14. A device for producing the cover arrangement of claim 1 and which is configured to apply the method of claim 11, wherein the device comprises a welding head, which is configured to establish the welding connection of the at least one base portion and the at least one fibrous layer, wherein the welding head has at least one substantially cylindrical protrusion, which is configured to be pressed against the at least one base portion and the at least one fibrous layer to establish the welding connection.

15. The device according to claim 14, wherein the at least one protrusion is conically formed with a wider base than tip.

Description

[0060] Further embodiments of the cover arrangement and the method according to the invention may be derived from the description of the embodiments shown in the figures and from the figures.

[0061] FIG. 1 shows a perspective view of an example of a cover arrangement according to the invention, with the bottom side of an engine top cover facing upwards, which is the opposite direction of the normal mounting position, where the bottom side faces downwards.

[0062] FIG. 2a to c show schematic cross section view of examples of cover arrangement according to FIG. 1.

[0063] FIG. 3a shows, in a schematic side view, an embodiment of the device according to the invention comprising an ultrasonic welding head suitable for the realization of the welding connection between the base portion of the mounting part and the fibers of the fibrous layer of a cover arrangement according to the invention.

[0064] FIG. 3b shows, in a side view, another embodiment of the device according to the invention comprising an ultrasonic welding head suitable for the realization of the welding connection between the base portion of the mounting part and the fibers of the fibrous layer of a cover arrangement according to the invention.

[0065] FIG. 4a schematically shows the steps of the method for connecting a mounting part to a cover according to an embodiment of the invention.

[0066] FIG. 4b schematically shows the steps of the method for connecting a mounting part to a cover according to another embodiment of the invention.

[0067] FIG. 1 shows the cover arrangement 1, with the bottom side of an engine top cover (engine top cover) facing upwards, being the opposite direction of the normal mounting position, where the bottom side faces downwards, with the body 2 formed with at least one fibrous carrier layer. The arrangement 1 is configured for reducing the noise emitted by a motor vehicle part, here in particular of the engine of a motor vehicle. The engine cover shows four thermoplast base portions 10 of a mounting part, which are connected to the fibrous carrier layer of the engine top cover 2 by a welding connection 12. The thermoplast may be polyamide 6.

[0068] Furthermore the base portion 10 is of the example shown is built to receive a rod shaped protrusion to form the mount between the cover and the engine. The rod shaped protrusion might be permanently fixed to the engine block. This type of fixations are known in the art, however not the welding connection of the base plate to the fibrous carrier layer.

[0069] FIG. 2a shows that the cover 2, which is an engine top cover, of the cover arrangement 1 consists of a fibrous carrier layer 3 and an optional open-cell PU light foam layer 4, being superposed over the full area of the cover, in the embodiment shown. The base portion 10 is made of a thermoplast and has a plate portion 11 and has hollow-pin-shaped parts 12, here a number of six protrusions being shown, which are integral with the plate portion 11. The pins are produced by an ultrasonic welding head having corresponding cylindrical pins, for example.

[0070] FIG. 2b shows that the cover 2, which is an engine top cover, of the cover arrangement 1 consists of a fibrous carrier layer 3, an optional open-celled PU light foam layer 4, an optional scrim layer 6 on the B-side of the cover 2 and a side decoration layer 5 on the A-side of the cover 2, in the embodiment shown. Similar to FIG. 2a, the base portion 10 is made of a thermoplast and has a plate portion 11 and has hollow-pin-shaped parts 12, here also a number of six protrusions being shown, which are integral with the plate portion 11. The fibrous carrier layer 3 may have a different thickness compared to the fibrous carrier layer 3 of FIG. 2a and the light foam layer 4 may have a different thickness compared to the light foam layer 4 of FIG. 2a. All layers might have variable thickness ranges; in particularly they might be thicker outside the area of the welding. The length of the pins 12 is adapted, compared to FIG. 2a, to also at least partly penetrate into the fibrous carrier layer 3, for allowing establishing the welding connection between the thermoplast of the pins 12 and the fibers of the fibrous carrier layer 3.

[0071] The A-side of an engine top cover is the side of the cover, which typically faces upwards, the B-side, is the opposite side, i.e. the bottom side. The terms up and low can be understood when considering that the mounting part is intended to be fixed at the bottom side of the cover in a mounting position, which means that the bottom side of the cover is facing the engine bay or the ground, respectively, i.e. the normal vector of the bottom side is substantially parallel to the positive direction of gravity.

[0072] The decoration layer 5 may comprise a textile fabric, for instance a nonwoven scrim layer, woven or knitted fabric and or a polymeric film, for instance a thermoplastic polyurethane film. The textile fabric is preferably made of a thermoplastic material that will not melt under 220 C., for instance polyester, preferably polyethylene terephthalate (PET) or polybutylene terephthalate (PBT).

[0073] FIG. 2c shows a basic embodiment of a cover arrangement 1, having a cover 2 including superposed the fibrous carrier layer 3 and the optional light foam layer 4. The mounting part 10 was welded by ultrasonic welding of a base plate 11 to the outer surface of the fibrous layer, thereby achieving an acoustically self-dampening configuration. Also here the welding caused a material connection between the surface of the fibrous carrier layer and the base plate, as well as a penetration in part of the base plate material in the carrier layer here shown in the form of protrusions. If no optional layer are available between the base plate and the carrier layer at the area to be welded, of if only a thin nonwoven scrim layer is available the penetration of the base plate material in the fibrous carrier layer can be minimal to still obtain a good durable connection between the fibrous carrier layer and the base plate, as long as the in between scrim layer can be punctured by the welding head, to obtain a direct connection between the material of the base plate and the material of the fibrous carrier layer. Optionally the scrim layer can be dismissed in the area of the welding connection to ensure a direct welding to the fibrous carrier layer. Penetration in part in the fibrous layer is however preferred as the connection is more strong and durable.

[0074] In FIG. 3a, the welding head 20 is shown, having four cylindrical pins 22 extending from a welding head base 21. The pins serve to transfer the ultrasonic energy from the welding head to the target, which, primarily, is theinitially fully plain shapedbase portion 11. The mounting part is mounted to the cover by a welding connection of the base portion 10 and at least one fibrous carrier layer 3, wherein the welding connection is realized by an ultrasonic welding machine having an ultrasonic welding head, in the embodiments shown here.

[0075] FIG. 3b shows the device being a welding head 20 with base part 21 and protrusions 22, the letter being arranged distal to the base part on top of the end of a longitudinal section 23 of the base part, which extends along the long axis Z of the welding head from the base part 21. The protrusion 22, as can be seen in FIG. 4c, has one first section 22a, which is arranged proximal to the base part, and integrally formed with the base part 21, and a second section 22b, which is arranged distal to the base part 21 and is the section which makes first contact with the target for receiving the ultrasonic energy, e.g. the base portion of the mounting part.

[0076] The second section 22b is cone-shaped, which results in an optimal energy transfer and also allows an efficient penetration of layers of the layer setup. The first section 22a, which preferably forms the transition section of the protrusion to the base part, also has a substantially cone-shape, which preferably has a concavely shaped wall, which means in case of a symmetrical cone that the cone side wall is dented towards the cone symmetry axis. Said shape allows for easily pulling out the welding head's protrusions from the layer setup after they had penetrated a layer setup and established the welding connection.

[0077] FIG. 4a schematically shows the steps of the method for connecting a mounting part to a cover according to an embodiment of the invention. The method 100 is a method for connecting at least one mounting part with a cover, the mounting part being configured for mounting the cover to a vehicle, in particular the cover being an engine top cover for covering the engine of the vehicle from above (e.g. the engine top cover 2 or 2), the cover having superposed layers, including, at least, a foam layer (e.g. the light foam layer 4 or 4) and a fibrous carrier layer(e.g. the fibrous carrier layer 3 or 3), the at least one mounting part having at least one base portion (e.g. the base portion 10 or 10) made from a thermoplast, comprising the steps: [0078] (101) mounting the at least one mounting part to the cover by [0079] (102) generating at least one welding connection of the at least one base portion and at least one fibrous carrier layer.

[0080] As shown in FIG. 4b, the method step 101 of mounting the at least one mounting part to the cover preferably comprises the steps of [0081] (104) penetrating the light foam layer by at least a part of at least one base portion; [0082] (105) at least partly penetrating the fibrous carrier layer by said part of the base portion.
the method step 101 of mounting the at least one mounting part to the cover preferably comprises the steps of [0083] (103) pressing the ultrasonic welding head of an ultrasonic welding machine against a base portion of a mounting part, thereby melting and displacing some thermoplast material of the base portion towards the at least one fibrous carrier layer, [0084] (104) then penetrating the light foam layer by the thermoplast material using the ultrasonic welding head, and [0085] (105) then penetrating the at least fibrous carrier layer at least in part by the thermoplast material using the ultrasonic welding head.

[0086] In the last step, the welding connection between the thermoplast material with the at least one fibrous carrier layer is formed using the ultrasonic welding head, thereby, preferably, creating an acoustically self-dampened cover arrangement.