VEHICLE COCKPIT COMPONENT PROVIDED WITH AN IMPROVED HEATING DEVICE

Abstract

A vehicle cockpit component (10, 12, 14, 16, 18) with a heating device that comprises a polyurethane-based foam charged and/or impregnated with an electrically conductive filler (1) which is directly connected to means for generating a potential difference (7a, 7b; 11a, 11b; 13a, 13b) for generating heat by Joule effect is provided. The polyurethane-based foam charged and/or impregnated with an electrically conductive filler (1) is used for manufacturing the padding or the upholstery of the vehicle cockpit component (10, 12, 14, 16, 18) or one or more portions of the padding or upholstery. The heating device is intrinsic to the vehicle cockpit component and does not require the provision of additional, separate components.

Claims

1. A vehicle cockpit component comprising at least a supporting frame and a padding fitted on the supporting frame, wherein the vehicle cockpit component is provided with a heating device, wherein the heating device comprises a polyurethane-based foam with an electrically conductive filler, wherein the polyurethane-based foam with the electrically conductive filler is directly connected to means for generating a voltage difference, whereby heat is generated by Joule effect in the heating device, and wherein the heating device forms the padding of the vehicle cockpit component, at least at one or more portions of the padding.

2-4. (canceled)

5. The vehicle cockpit component according to claim 1, wherein the polyurethane-based foam with the electrically conductive filler is arranged between a pair of metal electrodes and coupled to the pair of metal electrodes, and wherein the metal electrodes of the pair of metal electrodes are bonded to the polyurethane-based foam with the electrically conductive filler and are connected to a control and power generation circuit.

6. The vehicle cockpit component according to claim 1, wherein the polyurethane-based foam with the electrically conductive filler is arranged between a pair of metal electrodes and coupled to the pair of electrodes, and wherein the electrodes of the pair of electrodes are obtained by means of flexible printed circuit boards and are connected to a control and power generation circuit.

7. The vehicle cockpit component according to claim 1, wherein the polyurethane-based foam with the electrically conductive filler is arranged between a pair of metal electrodes and coupled to the pair of electrodes, and wherein the electrodes of the pair of electrodes are obtained by means of printed conductive inks and connected to a control and power generation circuit.

8. The vehicle cockpit component according to claim 1, wherein the polyurethane-based foam with the electrically conductive filler is provided with a pair of metal electrodes which are embedded in the polyurethane-based foam with the electrically conductive filler and connected to a control and power generation circuit.

9. The vehicle cockpit component according to claim 1, wherein the polyurethane-based foam with the electrically conductive filler is a polyurethane foam charged with an electrically conductive filler.

10-11. (canceled)

12. The vehicle cockpit component according to claim 1, wherein the vehicle cockpit component is selected from the group consisting of a vehicle seat, a vehicle seat cushion, a vehicle seat backrest, a vehicle seat armrest, a vehicle seat headrest, an inner panel of a vehicle door, and a cockpit headliner.

13-19. (canceled)

20. The vehicle cockpit component according to claim 9, wherein the polyurethane-based foam with the electrically conductive filler comprises a polyurethane matrix and electrically conductive particles dispersed in the polyurethane matrix, and wherein the concentration of the electrically conductive particles in the polyurethane matrix is in the range between the percolation threshold and the saturation threshold of the resulting polyurethane-based foam with the electrically conductive filler.

21. The vehicle cockpit component according to claim 20, wherein the electrically conductive particles are selected from the group consisting of metal particles, carbon black particles, graphite particles, graphene particles, graphene oxide, graphene nanoplatelets, carbon fibres, and carbon nanotubes.

22. The vehicle cockpit component according to claim 1, wherein the polyurethane-based foam with the electrically conductive filler is a polyurethane foam impregnated with an electrically conductive filler.

23. A vehicle cockpit component comprising at least a supporting frame and an upholstery fitted on the supporting frame, wherein the vehicle cockpit component is provided with a heating device, wherein the heating device comprises a polyurethane-based foam with an electrically conductive filler, wherein the polyurethane-based foam with the electrically conductive filler is directly connected to means for generating a voltage difference, whereby heat is generated by Joule effect in the heating device, and wherein the heating device forms the upholstery of the vehicle cockpit component, at least at one or more portions of the upholstery.

24. The vehicle cockpit component according to claim 23, wherein the polyurethane-based foam with the electrically conductive filler is arranged between a pair of metal electrodes and coupled to the pair of metal electrodes, and wherein the metal electrodes of the pair of metal electrodes are bonded to the polyurethane-based foam with the electrically conductive filler and are connected to a control and power generation circuit.

25. The vehicle cockpit component according to claim 23, wherein the polyurethane-based foam with the electrically conductive filler is arranged between a pair of electrodes and coupled to the pair of electrodes, and wherein the electrodes of the pair of electrodes are obtained by means of flexible printed circuit boards and are connected to a control and power generation circuit.

26. The vehicle cockpit component according to claim 23, wherein the polyurethane-based foam with the electrically conductive filler is arranged between a pair of electrodes and coupled to the pair of electrodes, and wherein the electrodes of the pair of electrodes are obtained by means of printed conductive inks and connected to a control and power generation circuit.

27. The vehicle cockpit component according to claim 23, wherein the polyurethane-based foam with the electrically conductive filler is provided with a pair of metal electrodes which are embedded in the polyurethane-based foam with the electrically conductive filler and connected to a control and power generation circuit.

28. The vehicle cockpit component according to claim 23, wherein the polyurethane-based foam with the electrically conductive filler is a polyurethane foam charged with an electrically conductive filler.

29. The vehicle cockpit component according to claim 23, wherein the polyurethane-based foam with the electrically conductive filler is a polyurethane foam impregnated with an electrically conductive filler.

30. The vehicle cockpit component according to claim 28, wherein the polyurethane-based foam with the electrically conductive filler comprises a polyurethane matrix and electrically conductive particles dispersed in the matrix, and wherein the concentration of the electrically conductive particles in the polyurethane matrix is in the range between the percolation threshold and the saturation threshold of the resulting polyurethane-based foam with an electrically conductive filler.

31. The vehicle cockpit component according to claim 30, wherein the electrically conductive particles are selected from the group consisting of metal particles, carbon black particles, graphite particles, graphene particles, graphene oxide, graphene nanoplatelets, carbon fibres, and carbon nanotubes.

32. The vehicle cockpit component according to claim 23, wherein the vehicle cockpit component is selected from the group consisting of a vehicle seat, a vehicle seat cushion, a vehicle seat backrest, a vehicle seat armrest, a vehicle seat headrest an inner panel of a vehicle door, and a cockpit headliner.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0073] Further features and advantages of the invention will become more evident from the detailed description of some preferred embodiments thereof, given by way of non-limiting example, with reference to the attached drawings, in which:

[0074] FIG. 1 schematically shows a vehicle seat provided with a heating device according to a first preferred embodiment of the invention.

[0075] FIG. 2 schematically shows a vehicle seat provided with a heating device according to a first preferred embodiment of the invention.

[0076] FIG. 3 schematically shows the structure of a possible polyurethane-based foam charged with an electrically conductive filler that can be used for manufacturing the heating device of the vehicle seats of FIGS. 1 and 2.

[0077] FIG. 4 schematically shows the structure of another possible polyurethane-based foam charged with an electrically conductive filler that can be used for manufacturing the heating device of the vehicle seats of FIGS. 1 and 2.

[0078] FIG. 5 schematically shows the structure of a further possible polyurethane-based foam charged with an electrically conductive filler that can be used for manufacturing the heating device of the vehicle seats of FIGS. 1 and 2.

[0079] FIG. 6 schematically shows a first possible construction of the heating device to be used in the vehicle seat of FIG. 1 or FIG. 2.

[0080] FIG. 7 schematically shows a second possible construction of the heating device to be used in the vehicle seat of FIG. 1 or FIG. 2.

[0081] FIG. 8 schematically shows a third possible construction of the heating device to be used in the vehicle seat of FIG. 1 or FIG. 2.

DESCRIPTION OF EMBODIMENTS

[0082] In the following description of preferred embodiments of the invention, reference will be made to a vehicle seat provided with a heating device. More specifically, reference will be made to a vehicle seat provided with a heating device at the cushion area and/or at the backrest area.

[0083] Such application, although particularly advantageous, shall not be intended as limiting and the invention could be also implemented for manufacturing several other components of a vehicle cockpit.

[0084] First of all, in case the vehicle seats comprise one or more armrests and/or a headrest, it is possible to envisage to apply the invention to the manufacturing of such armrest(s) and/or headrest.

[0085] Secondly, the invention finds application in manufacturing components of the cockpit other than the vehicle seats. In general, the invention can be used for manufacturing any component of the cockpit that comprises a padding and/or an upholstery, including the inner panels of the vehicle doors and the cockpit headliner.

[0086] The invention essentially relates to a cockpit component, such as a vehicle seat, provided with a heating device including a polyurethane-based foams charged and/or impregnated with an electrically conductive filler, such device being used for manufacturing the padding and/or the upholstery of the cockpit component.

[0087] By way of non-limiting example, a vehicle seat 10 according to a preferred embodiment invention is schematically shown in FIG. 1.

[0088] The vehicle seat 10 includes a seat cushion 12 and a seat backrest 14. In the shown example, the vehicle seat 10 further comprises an armrest 18 and a headrest 16.

[0089] In a per se now manner, each component of the vehicle seat 10 includes a rigid supporting frame (not visible in FIG. 1), a padding, covering the rigid frame and guaranteeing an adequate comfort to the users, and an upholstery, fitted onto the padding and intended to provide the desired surface properties as well as the desired aesthetical appearance to the corresponding component.

[0090] In the embodiment of FIG. 1, a polyurethane-based foam charged with an electrically conductive filler 1 is used for manufacturing the padding of the seat cushion 12 and of the seat backrest 14.

[0091] In general, such polyurethane-based foam charged and/or impregnated with an electrically conductive filler 1 can be used for manufacturing the padding of the seat cushion 12 or one or more portions thereof and/or for manufacturing the padding of the seat backrest 14 or one or more portions thereof.

[0092] In addition, such polyurethane-based foam charged and/or impregnated with an electrically conductive filler 1 can be used for manufacturing the padding of the armrest 18 or one or more portions thereof and/or for manufacturing the padding of the headrest 16 or one or more portions thereof.

[0093] FIG. 2 shows an alternative embodiment of the invention in which, a polyurethane-based foam charged and/or impregnated with an electrically conductive filler 1 is used for manufacturing the upholstery of the seat cushion 12 and of the seat backrest 14.

[0094] In general, such polyurethane-based foam charged with an electrically conductive filler 1 can be used for manufacturing the upholstery of the seat cushion 12 or one or more portions thereof and/or for manufacturing the upholstery of the seat backrest 14 or one or more portions thereof.

[0095] In addition, such polyurethane-based foam charged and/or impregnated with an electrically conductive filler 1 can be used for manufacturing the upholstery of the armrest 18 or one or more portions thereof and/or for manufacturing the upholstery of the headrest 16 or one or more portions thereof.

[0096] As shown in FIG. 2, according to this embodiment of the invention, the polyurethane-based foam charged and/or impregnated with an electrically conductive filler 1 will be sandwiched between an inner base layer 2 and an outer decorative layer 4, thus forming an intermediate layer of the upholstery with a multilayer structure.

[0097] As better shown in FIGS. 3-5, the polyurethane-based foam charged and/or impregnated with an electrically conductive filler 1 comprises a polyurethane matrix 3 charged and/or impregnated with electrically conductive particles 5, 5′, 5″.

[0098] The conductive particle can be carbon-based particles and/or metal-based particles, wherein metal-based particles are meant to include both metal and alloys that are electrically conductive.

[0099] Such conductive particles can be three-dimensional particle 5, such as metal particles and/or carbon black particles (see FIG. 3), substantially two-dimensional particles 5′, such as graphite or graphene particles or graphene oxide or graphene nanoplatelets (see FIG. 4), substantially mono-dimensional particles 5″, such as carbon fibres or carbon nanotubes (see FIG. 5), or any combination thereof.

[0100] Depending on the characteristics of the matrix 3 and of the filler particles 5, 5′, 5″, the concentration of such filler particles will be selected in order to be in the range between the percolation threshold and the saturation threshold of the resulting composite material.

[0101] Preferably, in order to effectively use the polyurethane foams charged with electrically conductive fillers for generating heat, the concentration of electrically conductive particle will be selected so as to be close to the saturation threshold, for instance in the 50% of the range between the percolation threshold and the saturation threshold closer to the saturation threshold, preferably in the 20% of said range closer to the saturation threshold.

[0102] In a manner known per se, the polyurethane matrix 3 of the foam is obtained from a first component containing at least one isocyanate and a second component containing at least one polyol.

[0103] The first and second components are mixed and poured into a metal mould, thus allowing the expansion and formation of the foam. The expansion is due to the carbon dioxide produced by the reaction between isocyanates and water, while gelation (which is responsible of the softness and flexibility of the foam) is obtained by the reaction between isocyanates and the —OH groups of polyols.

[0104] If use of a foam charged with an electrically conductive filler is envisaged, in order to obtain the foam of the invention, electrically conductive particles 5, 5′, 5″ are added to the first component or to the second component. The component is then subjected to a mixing step, intended to obtain a uniform distribution of the conductive particles within the component and, subsequently, in the resulting foam matrix. Such mixing step can be carried out, for instance, by mechanical stirring, by magnetic stirring, or by applying ultrasonic vibrations.

[0105] Said mixing step can be optionally followed by a step of thermal treatment, allowing to consolidating the resulting foam matrix. As mentioned above, the concentration of electrically conductive particles will be selected so that the resulting composite material is in the range between the percolation threshold and the saturation threshold. More in detail, such concentration will be preferably sufficiently high to ensure a good thermal conductivity of the resulting foam, so as to provide optimum transmission of generated heat to the outer surface of the vehicle seat; on the other hand, such concentration will be preferably sufficiently low to prevent the foam from becoming unstable or collapsing due to gravity effects related to the excessive presence of filler in the polyurethane matrix.

[0106] Thanks to the presence of electrically conductive particles, the foam charged with an electrically conductive filler 1 can be used for generating heat by Joule effect.

[0107] However, the Applicant has observed that addition of electrically conductive particles, namely in a concentration suitable for ensuring a good thermal/electrical conductivity of the resulting foam, might result in a deterioration of the mechanical properties of such foam, and even in the risk that the cell structure of the foam collapses.

[0108] Since according to the invention the foam is used as padding and/or upholstery of the vehicle cockpit component, such deterioration of its mechanical properties is not envisaged.

[0109] Accordingly, measures are taken in order to provide a compensation to the deterioration of the foam mechanical properties due to the addition of the electrically conductive particles.

[0110] In a preferred embodiment of the invention, such measures include addition of one or more blowing agents to the first component and/or to the second components used for manufacturing the foam.

[0111] More particularly, the type and amount of blowing agent(s) will be selected as a function of the concentration of electrically conductive particles.

[0112] In addition, other optional ingredients, including catalysts, surfactants, conductive fillers and other suitable chemical reagents, may be added to the first component and/or to the second components used for manufacturing the foam according to desired mechanical properties of the resulting polyurethane matrix.

[0113] If use of a foam impregnated with an electrically conductive filler is envisaged, in order to obtain the foam of the invention, the polyurethane foam is immersed at least once in a solution containing at least one binder and at least one conductive filler, both uniformly distributed in the solution by mechanical agitation, by magnetic agitation or by applying ultrasonic vibrations.

[0114] Also in this case, during manufacturing of the polyurethane foam one or more blowing agents may be added into the composition, in order to compensate the deterioration of the foam mechanical properties due to subsequent impregnation with the electrically conductive filler.

[0115] Also in this case, a final step of thermal treatment, allowing to consolidating the foam matrix, could be envisaged.

[0116] It will be evident to the person skilled in the art that it will also be possible to provide a combination of the two techniques described above, and a polyurethane foam could be initially charged with an electrically conductive filler during its production, and then impregnated with an electrically conductive filler.

[0117] In this case, the electrically conductive filler used for charging the polyurethane foam can be either of the same type as the one used for impregnating the foam, or of a different type.

[0118] The polyurethane foam charged and/or impregnated with an electrically conductive filler can be used for generating heat by Joule effect.

[0119] To this purpose, according to the invention said foam charged and/or impregnated with an electrically conductive filler 1 is directly connected to means for generating a potential difference in order to obtain a heating (i.e. heat generating) device.

[0120] FIGS. 6-8 schematically show possible constructions of such heating device.

[0121] In the example of FIG. 6, the polyurethane foam charged and/or impregnated with an electrically conductive filler 1 is placed between a pair of metal electrodes 7a, 7b and coupled to them; said electrodes 7a, 7b being preferably placed on opposite sides of the foam and coupled to said foam by means of a conductive glue or paste or resin 9.

[0122] In the example in FIG. 7, the polyurethane foam charged and/or impregnated with an electrically conductive filler 1 is placed between a pair of electrodes 11a, 11b and coupled to them; said electrodes 11a, 11b being obtained from flexible printed circuit boards (FPCB).

[0123] Such flexible printed circuit boards may be replaced by electrically metal-based conductive inks, which can be printed on the foam for forming a pair of electrodes.

[0124] In the examples of FIG. 8, a pair of metal electrodes 13a, 13b are embedded in the polyurethane foam charged and/or impregnated with electrically conductive fillers 1. In this configuration, the metal electrodes 13a, 13b are preferably shaped as frame elements.

[0125] In all the above configurations, the electrodes 7a, 7b, 11a, 11b, 13a, 13b will be connected to a control and power generation circuit 15 comprising a control unit 17.

[0126] The control unit 17 is configured to apply an adequate potential difference between the electrodes, so that an electrical current passes through the polyurethane foam charged and/or impregnated with electrically conductive fillers 1 and heat is generated by Joule effect.

[0127] The control unit 17 is further configured to detect the electrical resistance offered by the polyurethane foam charged and/or impregnated with electrically conductive fillers 1 and to derive the temperature of such foam from the detected resistance, thanks to the relationship between temperature and electric resistivity of the foam.

[0128] In view of the above, temperature sensors can be advantageously omitted.

[0129] It is to be noted that the concentration of electrically conductive particles in the polyurethane foam can be selected so as to trigger a mechanism of self-regulation of the temperature of the resulting composite material: by applying a constant potential difference, the polyurethane foam charged and/or impregnated with electrically conductive fillers 1 reaches and maintains the desired temperature. Therefore, it can be considered a self-regulating heating device, which does not need the presence of temperature sensors.

[0130] By way of non-limiting examples, a foam charged with an electrically conductive filler according to the present invention could be obtained as follows:

[0131] Example 1: The foam is obtained through the reaction between polyol and isocyanate components, and at least one of them is containing nickel as metal-based electrically conductive filler. First, the polyol component is prepared by mixing and blending at least one polyol with one or more blowing agents. The polyols are polyether-based segments containing poly-ethylene oxide and poly-propylene oxide. The blowing agent is water. One or more surfactant and one or more catalysts may also be added. For instance, a silicone-based surfactant may be used and the catalysts can be primary, secondary, tertiary amines. In this example, the nickel particles are mixed in the polyol component by using mechanical stirring, in order to achieve uniform distribution of particles in the component. The nickel particles concentration is 50 wt %, close to saturation operating region. Then the isocyanate component, which could be toluene diisocyanate (TDI) or methylene diphenyl diisocyanate (MDI), is added to polyol component. The mixed components are poured into the mould, in order to obtain the foam as heater device. The obtained foam is characterized by a percolation threshold equal to 45 wt %, and a saturation threshold equal to 70 wt %.

[0132] Example 2: The foam is obtained through the reaction between polyol and isocyanate components, and at least one of them is containing carbon nanotubes as carbon-based electrically conductive filler. First, the polyol component is prepared by mixing and blending at least one polyol with one or more blowing agents. The polyols are polyether-based segments containing poly-ethylene oxide and poly-propylene oxide. The blowing agent is water. One or more surfactant and one or more catalysts may also be added. For instance, a silicone-based surfactant may be used and the catalysts can be primary, secondary, tertiary amines. In this example, the carbon nanotubes particles are mixed in the polyol component by using ultrasonication, in order to achieve uniform distribution of particles in the component. The carbon nanotubes particles concentration is 5 wt %, close to saturation operating region. Then the isocyanate component, which could be toluene diisocyanate (TDI) or methylene diphenyl diisocyanate (MDI), is added to polyol component. The mixed components are poured into the mould, in order to obtain the foam as heater device. The obtained foam is characterized by a percolation threshold equal to 1 wt %, and a saturation threshold equal to 6 wt %.

[0133] In both examples, the filler concentration is chosen in order to obtain a device with a good heating efficiency. The examples allow to understand that the filler type and size affect the filler concentration that is needed to obtain a high-performance heating device intrinsic to the vehicle seat.

[0134] On the other hand, the blowing agents are chosen in order to obtain a device with good mechanical properties, despite the addition of the filler.

[0135] As a non-limiting example, a foam impregnated with an electrically conductive filler according to the invention could be obtained as follows:

[0136] Example 3: Graphene nanoplates are dispersed in a tetrahydrofuran-based solution. At least one polyol is introduced into the solution, which polyol will act as a binder between the graphene nanoplates and polyurethane foam. The graphene nanoplates and the binder are evenly dispersed in the solution by magnetic agitation. The weight concentration of the graphene nanoplates in the tetrahydrofuran solution is 5%. The polyurethane foam (already formed) is immersed in the solution so that it is impregnated with the graphene nanoplates. Subsequently, the polyurethane foam is dried in an oven at a temperature of 60° C. in order to remove the residual solution. The impregnation, and subsequent drying, is repeated three times.

[0137] It is evident that the above detailed description has been given by way of example and several modifications and variations are possible without departing from the scope of protection of the invention as defined by the appended claims.

[0138] In detail, the materials used for manufacturing the polyurethane matrix, the nature and concentrations of the electrically conductive particles used as filler, the shape and size of the resulting foam as well as the specific constructional features of the electrodes and of the circuit connected thereto can be selected by the person skilled in the art according to his/her own knowledge as a function of the specific application and desired performances.

[0139] Moreover, the invention can be applied to a wide variety of component of the vehicle cockpit, including vehicle seats, inner panels of the vehicle doors and the cockpit headliner