INTERIOR TRIM PANEL FOR MOTOR VEHICLE

Description

[0001] The invention relates to an interior trim panel of a motor vehicle provided with an electrodynamic or magnetostrictive transducer.

[0002] It is known to produce such a panel making it possible to propagate within a motor vehicle interior the signal coming from an amplifier, the use of a transducer instead of a loudspeaker allowing in particular a saving of weight and space. Document EP1007390A1 discloses an interior trim panel for a motor vehicle, said panel comprising a molded core, said panel further comprising: a base overmolded by said core in a fixing zone, an electrodynamic or magnetostrictive transducer, said transducer being further provided with two electrical connectors,

[0003] Various problems arise when such an arrangement is implemented: simplifying the assembly, optimizing the transmission of the signal from the amplifier to the panel (via the transducer), ensuring the reliability of the electrical contacts, eliminating the risk of parasitic vibrations.

[0004] The aim of the invention is to propose a panel which makes it possible to reconcile these various requirements.

[0005] To this end, the invention proposes an interior trim panel for a motor vehicle, said panel comprising a molded core, said panel further comprising: a base overmolded by said core in a fixing zone, said base being provided with harpoons projecting from said core, a ring provided with means for receiving said harpoons in an interlocking manner, so as to associate said ring with said base, said ring being further provided with two electrical connectors intended to be connected to the outputs of an amplifier, the central orifice of said ring being provided with a thread, an electrodynamic or magnetostrictive transducer which is provided with a fixing part in the general shape of a threaded cylinder screwed into said orifice, the free end of said fixing part bearing in said zone so as to create a separation force between said ring and said base ensuring a tight contact between said harpoons and said receiving means, said transducer being further provided with two reciprocal electrical connectors on which each of said connectors bears respectively.

[0006] With the proposed layout: the mounting of the transducer on the panel is very simple since it is limited to the fitting of the ring and the screwing of the transducer onto the latter, the rotation stroke can be defined as a small angular sector in order to further simplify the mounting, the fact of embedding the base in the core makes it possible to ensure a continuous surface contact, and not a point contact (as would be the case for example in a fixing of the base by screw creating an air gap between said base and said core), between said base and the panel, and thus to optimize the transmission of the signal from the amplifier to the panel via the transducer, optimal electrical contacts result from the screwing operation which makes it possible to put the contactors and reciprocal contactors in reciprocal support,the free end of the fixing part bearing in the fixing zone makes it possible to create a separation force between the ring and the base and thus to ensure tight contact between said harpoons and said receiving means, which makes it possible to avoid play between the base and the ring and between the ring and the transducer, and therefore to avoid parasitic vibrations.

[0007] Other features and advantages of the invention will appear in the following description, given with reference to the attached figures, in which: [ Fig.1 ] is a schematic view in partial exploded perspective and in semi-transparent of a panel according to one embodiment, [ Fig.2 ] is a schematic, partially exploded sectional view of the panel of the figure 1 , [ Fig.3 ] is a schematic front view of the base, ring and transducer of the panel of the figure 1 , Fig.4 ] is a schematic view in partial section, not exploded, of the panel of the figure 1 , [ Fig.5 ] is a schematic front view corresponding to the figure 4 .

[0008] With reference to the figures, a motor vehicle interior trim panel 1 is described - for example a luggage compartment cover shelf, a storage bin cover or a backrest shell -, said panel comprising a molded core 2, said panel further comprising: a base 3 - in particular made of molded plastic material - overmolded by said core in a fixing zone 4, said base being provided with harpoons 5 projecting from said core, a ring 6 - in particular made of molded plastic material - provided with means - arranged here on the periphery of said ring - for receiving 7 in fitting of said harpoons - said means being arranged here on the periphery of said ring -, so as to associate said ring with said base, said ring being further provided with two electrical connectors 8 intended to be connected to the outputs of an amplifier, the central orifice 9 of said ring being provided with a thread 10, an electrodynamic or magnetostrictive transducer 11 which is provided with a fixing part 12 - in particular made of molded plastic material - in the general shape of a threaded cylinder screwed into said orifice, the free end 13 of said fixing part bearing in said zone - on said base in the embodiment shown,or even on the core in an embodiment not shown when said base is embedded in said core - so as to create a separation force between said ring and said base ensuring a tight contact between said harpoons and said receiving means, said transducer being further provided with two reciprocal electrical connectors 14 on which each of said connectors bears respectively.

[0009] Core 2 is in particular based on rigid or semi-rigid polyurethane foam, i.e. a non-elastically compressible foam (unlike the foams used, for example, to make seat cushions), said foam not being able to return to its initial geometry after having been compressed by 50% of its initial thickness.

[0010] Soul 2 is for example in the form: a block of polyurethane foam reinforced with glass fibers, or a "honeycomb" plate, particularly made of cardboard, the two sides of which are each covered with a layer of glass fibers embedded in rigid polyurethane foam.

[0011] According to the embodiment shown, the free end 13 is inscribed in a plane bearing in the fixing zone 4 inscribed in the same plane, so as to ensure surface contact between the two making it possible to optimize the transmission of the signal from the amplifier.

[0012] According to the embodiment shown, the connectors 8 - respectively or the reciprocal connectors 14 in a variant not shown - are in the form of terminals and the reciprocal connectors 14 - respectively or the connectors 8 in a variant not shown - in the form of concentric tracks, which makes it possible to guarantee electrical contact between the two regardless of the angular travel carried out to finalize the screwing of the transducer 11.

[0013] According to the embodiment shown, the terminals are in the form of pads 19 mounted on springs 20, so as to guarantee electrical contact with each corresponding track.

[0014] In a variant not shown, the terminals may be in the form of spring-loaded metal blades which press against the corresponding tracks, so as to guarantee electrical contact with said tracks.

[0015] In particular, the tracks extend to the choice: either, in the embodiment shown, according to two parallel angular sectors - which extend over 360° in the embodiment shown -, the terminals being arranged at radial dimensions - relative to the screwing axis 15 - corresponding to those of each of said sectors, or, in an embodiment not shown, according to two angular sectors arranged in the extension of one another, said terminals being arranged according to two different angular positions and according to the radial dimension of said sectors.

[0016] According to the embodiment shown, the transducer 11 - respectively or the ring 6 in a variant not shown - is provided with a circular rack cooperating with a lug 17 coming from the ring 6 - respectively or from the transducer 11 in a variant not shown -, said lug being arranged so that the screwing of the fixing part 12 requires a threshold force for said lug to pass from one notch 18 to the other of said rack, in order to prevent untimely unscrewing of said transducer.

[0017] According to a partially shown embodiment, the panel 1 further comprises two cables 21 for connection to an amplifier, said cables being connected to the connectors 8, said panel further comprising a trench for passage of said cables formed in the core 2.

Claims

1. A motor vehicle inner trim panel (1), said panel comprising a moulded core (2), said panel further comprising: • a base (3) overmoulded by said core in an fixing zone (4), said base being provided with harpoon (5) projecting from said core, • a ring (6) provided with receiving means (7) interlocking with said harpoon, so as to associate said ring with said base, said ring being further provided with two electric connectors (8) intended to be connected to the outputs of an amplifier, the central opening (9) of said ring being provided with a thread (10), • an electrodynamic or magnetostrictive transducer (11) which is provided with an attachment portion (12) in the general form of a threaded cylinder screwed into said opening, the free end (13) of said attachment portion bearing in said zone so as to create a separation force between said ring and said base ensuring gripping contact between said harpoon and said receiving means, said transducer being further provided with two reciprocal electric connectors (14) on which each of said connectors bears respectively.

2. The panel according to claim 1, characterized in that the core (2) is based on rigid or semi-rigid polyurethane foam.

3. The panel according to one of claims 1 or 2, characterized in that the free end (13) is inscribed in a plane bearing in the fixing zone (4) lying in the same plane, so as to ensure surface contact between the two to optimise the transmission of the signal derived from the amplifier.

4. The panel according to any one of claims 1 to 3, characterized in that the connectors (8) - respectively or the reciprocal connectors (14) - are in the form of terminals and the reciprocal connectors (14) - respectively or the connectors (8) - in the form of concentric tracks.

5. The panel according to claim 4, characterized in that the terminals are in the form of studs (19) mounted on a spring (20), so as to ensure electrical contact with each corresponding track.

6. The panel according to claim 4, characterized in that the terminals are in the form of blades made of spring metal pressing against the corresponding tracks, so as to ensure electrical contact with said tracks.

7. The panel according to any one of claims 4 to 6, characterized in that the tracks extend: • either according to two parallel angular sectors, the terminals being disposed at radial dimensions corresponding to those of each of said sectors, • or according to two angular sectors disposed in the extension of one another, said terminals being disposed according to two different angular positions and according to the radial dimension of said sectors.

8. The panel according to any one of the preceding claims, characterized in that the transducer (11) - respectively or the ring (6) - is provided with a circular rack (16) cooperating with a lug (17) projecting from the ring - respectively or the transducer (11) -, said lug being arranged so that screwing of the attachment portion (12) requires a threshold force for said lug to pass from one notch (18) to another of said rack, in order to prevent inadvertent unscrewing of said transducer.

9. The panel according to any one of the preceding claims, characterized in that it further comprises two cables (21) for connection to an amplifier, said cables being connected to the connectors (8), said panel further comprising a trench for the passage of said cables formed in the core (2) .