Mounting architecture of an inertial electrodynamic transducer under a vehicle seat

Abstract

The invention relates to an architecture (1) for mounting an inertial electrodynamic transducer (2) under a seat (3) of a motor vehicle, comprising: a box (4) having an opening (5), a rigid plate (6), at least one electrodynamic transducer (2), a floor panel (12) of said vehicle having an upper face receiving said box, a floor mat (13) covering said panel, said box extending in front of and / or behind said seat, so as to present at least one extension zone (14) located directly below the feet of an occupant of said vehicle, said zone being covered by said mat, said mat resting in said zone on a rigid plate (15) covering said zone without being in contact with it, so as to prevent transmission of sound vibrations from said transducer to the feet of said passenger. Figure 1

Description

Title of the invention: Mounting architecture for an inertial electrodynamic transducer under a motor vehicle seat

[0001] The invention relates to a mounting architecture for an inertial electrodynamic transducer under a motor vehicle seat.

[0002] It is known to implement a mounting architecture for an inertial electrodynamic transducer under a motor vehicle seat, said architecture comprising: • a box defining an acoustic volume, said box having an opening facing upwards, • a rigid plate fixed at its periphery to the periphery of said opening by means of a decoupling means allowing its movement relative to said box so as to allow it to vibrate, • at least one electrodynamic transducer comprising a coil fixed under said plate, said transducer further comprising a magnet housed in a casing, said casing being mounted by means of a suspension device on said coil, so that said plate vibrates when said transducer is powered, • a floor panel of said vehicle, said panel having an upper surface receiving said box, • a floor mat covering said wall.

[0003] For the record, transduction is the operation that transforms one physical quantity into another, by means of a transducer which transforms the energy received in a given form, for example electrical energy, into usable energy in a different form.

[0004] In the context of the invention, it is a question of transforming an electrical signal into an acoustic signal by using as a radiating surface the rigid plate on which the transducer is fixed, for example in order to deliver a sound audible to an occupant of the seat (music, message, ...) or a sound signal in opposite phase with the sound signal corresponding to the noise in the passenger compartment when the vehicle is in motion.

[0005] It is recalled here that a transducer differs from a loudspeaker in the following way: • A loudspeaker comprises a magnet fixedly mounted on a support and a flexible diaphragm attached to a coil, said diaphragm vibrating when said loudspeaker is powered, • a transducer includes a coil fixedly mounted on a rigid plate and a magnet mounted by means of a suspension on said coil, so that said plate vibrates when said transducer is powered.

[0006] Ultimately, a loudspeaker is an autonomous system generating sound independently of the environment in which it is mounted, whereas a transducer uses the support on which it is fixed, in this case a rigid plate, to generate the expected sound.

[0007] In addition, the use of a transducer is advantageous because of its smaller size and lighter weight compared to a loudspeaker.

[0008] With the known embodiment, it may be desirable to extend the volume of the box, in particular in order to increase the level of sound pressure in low frequencies, in order to optimize sound transmission in said frequencies.

[0009] In order to achieve this, it may be necessary to extend the coverage of the floor wall by the box, said box then being able to present a part located directly under the feet of an occupant of the vehicle.

[0010] In such a configuration, the vibrations are then transmitted directly into the occupant's feet, which gives him an unpleasant sensation.

[0011] The invention aims to overcome this drawback.

[0012] To this end, the invention proposes a mounting architecture for an inertial electrodynamic transducer under a motor vehicle seat, said architecture comprising: • a box defining an acoustic volume, said box having an opening facing upwards, • a rigid plate fixed at its periphery to the periphery of said opening by means of a decoupling means allowing its movement relative to said box so as to allow it to vibrate, • at least one electrodynamic transducer comprising a coil fixed under said plate, said transducer further comprising a magnet housed in a casing, said casing being mounted by means of a suspension device on said coil, so that said plate vibrates when said transducer is powered, • a floor panel of said vehicle, said panel having an upper surface receiving said box, • a floor mat covering said wall,

[0013] said architecture further having the following characteristics: • said box extends in front of and / or behind said seat, so as to present at least one extension area located directly below the feet of an occupant of said vehicle, • said area is covered by said carpet, • said carpet rests in said area on a rigid platform covering said area without being in contact with it, so as to avoid transmission of sound vibrations from said transducer to the feet of said passenger.

[0014] In this description, the terms of positioning in space (top, upper, lower, front, rear, ...) are taken with reference to the vehicle, said vehicle extending longitudinally (X axis) according to its length, transversely (Y axis) according to its width and vertically (Z axis) according to its height.

[0015] With the proposed arrangement, a vehicle occupant whose feet are located directly above the extension part of the box is not subject to an unpleasant sensation, due to the absence of contact between the platform and the extension area of ​​the box.

[0016] Other features and advantages of the invention will become apparent from the following description, made with reference to the accompanying figures, in which:

[0017] [Fig-1] is a general schematic view along a transverse direction of a architecture according to a specific design

[0018] [Fig.2] is a schematic view of an inertial electrodynamic transducer arranged in the architecture represented in [Fig.1].

[0019] With reference to the figures, a transducer mounting architecture 1 is described. 2. Inertial electrodynamics under a seat 3 of a motor vehicle, said architecture comprising: • a box 4 defining an acoustic volume, said box having an opening 5 opening upwards, • a rigid plate 6 fixed at its periphery to the periphery of said opening by means of a decoupling means 7 allowing its movement relative to said box so as to allow it to vibrate, • at least one electrodynamic transducer 2 comprising a coil 8 fixed under said plate, said transducer further comprising a magnet 9 housed in a casing 10, said casing being mounted by means of a suspension means 11 on said coil, so that said plate vibrates when said transducer is powered, • a floor panel 12 of said vehicle - in particular made of sheet metal - said panel having an upper face receiving said box, • a floor mat 13 - for example carpet, plastic sheeting, etc. - covering said wall,

[0020] said architecture further having the following characteristics: • said box extends in front of and / or behind said seat, so as to present at least one extension zone 14 located directly below the feet of an occupant of said vehicle, • said area is covered by said carpet, • The said mat rests in the said area on a rigid platform 15 covering the said area without being in contact with it, so as to prevent the transmission of sound vibrations from the said transducer to the feet of the said passenger.

[0021] According to the embodiment shown, the platform 15 rests on the floor wall 12 by means of a plurality of feet 16 extending from an underside of the platform.

[0022] According to one embodiment, the plate 15 is separated from the extension zone 14 of the box 4 by at least 4 mm, so as to guarantee the absence of contact between the two.

[0023] According to one embodiment, the tray 15 is made of molded plastic material, the feet 16 being molded in one piece with said tray.

[0024] According to another embodiment, the feet 16 are made from an underlayer of plastic material overmolding the underside of the carpet 13.

[0025] According to another embodiment, the feet 16 are independent added elements - being for example made of wood, plastic material, etc.

[0026] According to the embodiment shown, the feet 16 are located on the periphery of the platform 15.

[0027] According to the embodiment shown, the free end of the feet is provided with a pad 17 acoustic decoupling made of elastically compressible material - for example foam or felt - interposed between said end and the floor wall 12.

[0028] According to the embodiment shown, box 4 comprises: • a main part 18 located under the seat 3 of the vehicle, said main part being based on a first material - for example, agglomerated foam flakes which may be covered with a waterproof layer of thermoplastic elastomer, such as ethylene propylene diene monomer -, • and an extension part 19 located in the extension zone 14, said extension part being based on a second material - for example based on polyurethane foam - said extension part communicating with said main part by at least one ancillary opening 20.

[0029] According to an embodiment not shown, the extension part 19 is filled with a porous material - for example based on foam or felt - so as to reinforce its mechanical strength, in particular if said part is based on a material of insufficient rigidity, being for example based on ethylene propylene diene monomer or agglomerated foam.

[0030] According to one embodiment, plate 6 has a Young's modulus between 108 and 109Pa.

[0031] According to one embodiment, the decoupling means 7 is in the form of a rubber or elastically compressible foam seal.

Claims

1. Demands Architecture (1) for mounting an inertial electrodynamic transducer (2) under a seat (3) of a motor vehicle, said architecture comprising: • a box (4) defining an acoustic volume, said box having an opening (5) opening upwards, • a rigid plate (6) fixed at its periphery to the periphery of said opening by means of a decoupling means (7) allowing its movement relative to said box so as to allow it to vibrate, • at least one electrodynamic transducer (2) comprising a coil (8) fixed under said plate, said transducer further comprising a magnet (9) housed in a casing (10), said casing being mounted by means of a suspension means (11) on said coil, so that said plate vibrates when said transducer is powered, • a floor panel (12) of said vehicle, said panel having an upper face receiving said box, • a floor mat (13) covering said wall, said architecture being characterized in that: • said box extends forward and / or backward said seat, so as to present at least one extension zone (14) located directly below the feet of an occupant of said vehicle, • said area is covered by said carpet, • said carpet rests in said area on a rigid platform (15) covering said area without being in contact with it, so as to avoid transmission of sound vibrations from said transducer to the feet of said passenger.

2. Architecture (1) according to claim 1, characterized in that the tray (15) is separated from the extension zone (14) of the box (4) by at least 4 mm.

3. Architecture (1) according to any one of claims 1 or 2, characterized in that the platform (15) rests on the floor wall (12) by a plurality of feet (16) originating from an underside face of said platform.

4. Architecture (1) according to claim 3, characterized in that the tabletop (15) is made of molded plastic material, the legs (16) being molded in one piece with said tabletop.

5. Architecture (1) according to any one of claims 3 or 4, characterized in that the feet (16) are located on the periphery of the platform (15).

6. Architecture (1) according to any one of claims 3 to 5, characterized in that the free end of the feet (16) is provided with an acoustic decoupling pad (17) made of elastically compressible material interposed between said end and the floor wall (12).

7. Architecture (1) according to any one of the preceding claims, characterized in that the box (4) comprises: • a main part (18) located under the seat (3) of the vehicle, said main part being based on a first material, • and an extension part (19) located in the extension area (14), said extension part being based on a second material, said extension part communicating with said main part by at least one auxiliary opening (20).

8. Architecture (1) according to the preceding claim, characterized in that the extension part (19) is filled with a porous material.

9. Architecture (1) according to any one of the preceding claims, characterized in that the plate (6) has a Young's modulus between 108 and 109Pa.

10. Architecture (1) according to any one of the preceding claims, characterized in that the decoupling means (7) is in the form of a rubber or elastically compressible foam seal.

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