MAIN FLOOR PART FOR A SMALL UTILITY VEHICLE

Abstract

Device for covering at least partially a vehicle floor pan comprising a sound absorbing material and at least a reinforcing block, whereby the reinforcing block is at least partially covered with the sound absorbing material characterised in that at least the lower face of the reinforcing block defines at least a dome shaped protrusion.

Claims

1. A device for covering at least partially a vehicle floor pan comprising a sound absorbing material and at least a reinforcing block, whereby the reinforcing block is at least partially covered with the sound absorbing material characterised in that at least the lower face of the reinforcing block defines at least a dome shaped protrusion.

2. The device according to claim 1, whereby the dome shaped protrusion is a shallow dome having a circular base.

3. The device according to claim 1, whereby the lower face of the reinforcing block contains dome shaped protrusions evenly spread over its surface.

4. The device according to claim 1 whereby the acoustic material is at least covering the surface including the dome shaped protrusion.

5. The device according to claim 1 whereby the reinforcing block has a lower density as the absorbing material.

6. The device according to claim 1 whereby the reinforcing block is made of a low density cellular material preferably by at least one of expanded polystyrene (EPS), expanded polyethylene (EPE), expanded polypropylene (EPP), a rigid polyurethane or a mixture of EPS and EPE.

7. The device according to claim 1 whereby the acoustic material is a foam material, preferably polyurethane foam.

8. The device according to claim 1 the top face of the reinforcing block facing away from the floor pan is covered with a covering layer preferably with one of a tufted carpet, a nonwoven carpet or a vinyl material.

9. The device according to claim 8 whereby the acoustic material is formed between the covering layer and the reinforcing block.

10. The device according to claim 9 whereby the top face of the reinforcing block means for keeping a distance between the carpet and the reinforcing block are given.

11. The device according to claim 9 whereby the means for keeping a distance are formed by either protrusions from the reinforcing block or by plastic springs placed between the reinforcing block and the covering layer.

12. The device according to claim 8, whereby the acoustic material is foam and the covering layer is a nonwoven or tufted carpet and the part is further comprising an additional layer between the foam and the covering layer to prevent foam strike through.

13. The device according to claim 12 whereby the additional layer is a fibrous nonwoven or textile layer, preferably one of a polyester or a polyolefin material.

14. The device according to claim 1 additionally comprising an insert in the reinforcing block with a higher density than the main body of the block.

15. The device according to claim 14 whereby the insert is made by at least one of expanded polystyrene (EPS), expanded polyethylene (EPE), expanded polypropylene (EPP), a rigid polyurethane or a mixture of EPS and EPE.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0018] FIGS. 1 to 6 are showing possible embodiments and examples, whereby the features shown in one example are not necessary all available in a part according to the invention. Particular embodiments or specific additional features can be taken or omitted depending on the actual case at hand.

[0019] All figures are using the same reference numbering for same or similar features.

[0020] FIG. 1 to FIG. 5 show examples of a floor device 1 covering a floor pan 4 and comprising a reinforcing block 5 with dome shaped protrusion 6 according to the invention.

[0021] FIG. 1 further shows a covering layer 2, in this case as an example a tufted carpet system. However also other types of material are possible, for instance one of a nonwoven carpet system, a Thermoplastic Polyolefin (TPO) layer or a natural or synthetic rubber layer or a combination of materials mentioned. The choice of material is dependent on the main use of the vehicle, however can also be dependent on regional preferences of the market for the vehicle.

[0022] The vehicle floor device as shown in FIG. 1 has the reinforcing block placed under the carpet and in direct contact with the floor pan. Although this is the cheapest solution and might be applicable in certain instances, there is a large likelihood that the part and or the use of such part in the vehicle will cause a high level of noise insight the compartment. However if the compartment is not occupied by passengers but merely used as a transport area for goods this might not be a problem. The covering layer and the reinforcing block can be connected to each other for instance by a chemical or mechanical bonding, for instance by a lamination or gluing step.

[0023] FIG. 2 shows the vehicle floor device of FIG. 1 further comprising an acoustic layer 3 placed between the lower area of the reinforcing block 5 and the floor pan 4. Whereby the full area between the reinforcing block 5 and eventually some overhanging floor covering 2 is preferably filled as shown, with the acoustic absorbing material 3. The acoustic material 3 is shown as an open cell polyurethane foam layer as an example. This can be a slab foam, eventually formed to follow the contours, or it can be foamed directly together with at least the reinforcing block embedded.

[0024] Other materials that are able to form an acoustic absorbing and or decoupling layer can be used to form the acoustic material layer 3, for instance a fibrous or felt layer. Preferably the fibrous or felt layer is formed such that it will follow the contour of the floor pan. Preferably the felt layer will embed the reinforcing block, similar to a foam layer applied in a reaction injection moulding layer. For instance fibre laydown machines able to lay fibrous material in 3-D shape would be advantageously used. However also a looser fibrous material that is able to adjust to the form moulded and laminated in a one or two step process can form a layer that follows the contours necessary.

[0025] The felt layer is preferable made of shoddy cotton or other fibrous material preferably including a suitable binder. Also fibrous mixtures containing fibrous or foam waste material can be used, eventually combined with virgin fibres.

[0026] Although FIG. 2 is showing the acoustic layer fully embedding the reinforcing block at least for the surface directed towards the floor pan, also less material can be used to achieve at least some noise abatement. At least the areas under the dome shaped protrusion should be covered with an acoustic material, comparable with the material disclosed so far. This can be easily achieved by placing a thin layer of material underneath the part and placing the part on top of it. Alternatively the area is covered with a mat or sheet of absorbing material, glued to the domes and or to the rim of the reinforcing block, so it forms one part and not separate layers, enabling a more easy assemblage of the floor device and the vehicle.

[0027] FIG. 3 shows the device of FIG. 2 further comprising channels 7 formed in the reinforcing block 5. These channels are mainly beneficial if the absorbing layer 3 is a foam material that is applied to the device in a reaction injection moulding process step, whereby the reinforcing block is placed in a mould and the foam is applied as a liquid, that reacts in the mould to become a foam, thereby flowing around the reinforcing block and embedding the block in the foam. The foam channels will help in forming a better bond between the foam and the block. It can further help in bonding any of the additional covering layers.

[0028] FIG. 4 shows the device of FIG. 3 further showing additional features that can be used alone or in combination.

[0029] Firstly the acoustic absorbing layer 3 may also be placed or injected between the top surface of the reinforcing block and the covering system used. This will have a beneficial effect on the overall acoustic performance of the floor device when used in the vehicle. Further it will soften the covering layer slightly, or just enough, to give the passenger a more comfortable feel or it might enable a soft layer to prevent damage to transported goods.

[0030] It might also enhance the lamination of the covering system with the other layers in particularly the reinforcing block.

[0031] To prevent foam strike through in the top covering layer an additional fibrous nonwoven or textile layer (not shown) can be placed under the covering system. This layer should be chosen such that the foam will be hampered in its flow. Preferably this layer is one of a polyester or polyolefin, polypropylene or polyethylene, nonwoven. The layer can be made of staple fibres or of continuous filament material. Binder can be used when necessary.

[0032] For ease of process, it is beneficial to apply the layer to the part together with the absorbing layer underneath, for instance in a one-step foam reaction injection moulding process. However the top acoustic layer can also be applied separately in a process step before or after application of the lower absorbing layer. Furthermore the material between the carpet and the reinforcing layer might be different —materially or functionally— from the material at the lower side of the reinforcing block and facing the floor pan during use.

[0033] To ease flow of foam between the covering layer and the reinforcing block the use of spacers (8) might be beneficial. For instance in the form of protrusions in the surface of the reinforcing block or by using spring elements for instance made of plastic which keep a space between the covering layer and the reinforcing block without forming a hard point in the final product. The spring elements can be for instance in the form of plastic loops or half loops perpendicular to the surface of the reinforcing block. These elements can be embedded partly in the reinforcing block to prevent them from moving during the foaming process.

[0034] The acoustic performance of the structural floor can be further enhanced by adding a heavy layer patched on between the reinforcing block and the acoustic material layer (FIG. 5, 9)

[0035] For increasing the local stiffness as might be needed for keeping the shaft of a baby seat and holding it during a crash, it might be necessary to include an insert in the reinforcing block with a higher density than the reinforcing block. (FIG. 5, 10)

[0036] FIG. 6 shows the reinforcing block with the domes regularly spaced on the surface of the site that will be facing the floor pan.

[0037] FIG. 7 shows the structural load floor schematically to show the dimensions preferred (drawing not to scale). The reinforcing block 5 is embedded in the absorbing layer 3. Preferably the absorbing layer is formed with a thickness (b) of at least 4 mm, preferably between 6 and 8 mm. Whereby the thickness of the absorbing layer underneath the lowest point of the dome is at least 4 mm and preferably between 6 and 8 mm, to achieve an acoustic absorbing effect. However it might be beneficial to fill the space between the reinforcing block and floor pan completely with foam. Preferably the foam is an open cell foam or an porous foam to increase the acoustic performance further.

[0038] Although at least the areas of the reinforcing block that would have been in contact with the floor pan should have an absorbing layer between the block and the floor pan, however by filling the space between the whole surface of the reinforcing block and the floor pan with the acoustic material the acoustic properties as well as the load bearing properties can be optimised.

[0039] Preferably the load bearing properties of the acoustic absorbing foam should be between 120 and 150 Pa.