Automotive seat trim element
A sealed acoustic insulation wall with a compressible material addresses the challenge of optimizing acoustic wave transmission and comfort in seat upholstery elements by channeling waves through an opening, enhancing both sound quality and seating comfort.
Patent Information
- Application Number
- FR2024001667
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2024-02-20
- Publication Date
- 2026-02-27
- Estimated Expiration
- 2044-02-20
Smart Images
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Abstract
Description
Title of the invention: Motor vehicle seat upholstery element
[0001] The invention relates to a seat upholstery element for a motor vehicle.
[0002] It is known to produce a trim element - such as a headrest, a backrest or part of a backrest - for a motor vehicle seat, said element comprising: • a padding block made of elastically compressible, porous material, said block having a face for receiving an occupant of said seat, said block being provided with a cavity having an opening leading to said receiving face, • a rigid plate fixed at its periphery, by means of a decoupling means, at the periphery of said opening so as to obscure it, said plate having an inner face turned towards said cavity, • an inertial electrodynamic transducer comprising a coil and a magnet fixed on a support, said support being mounted by means of a suspension means attached to said coil, so that said plate vibrates when said transducer is powered, said coil being fixed on said inner face.
[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, for example acoustic.
[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 comprises 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] However, with the realization of the prior art described above, the problem arises of having a closed "acoustic loading cavity" - that is to say a cavity where the acoustic waves from the transducer are channeled through the opening of said cavity - in order to allow optimization of the transmission of said acoustic waves.
[0009] In addition, it is imperative to preserve the comfort of a seat occupant with regard to the receiving face of the block.
[0010] The invention aims to provide an arrangement that meets these expectations.
[0011] To this end, the invention proposes a seat upholstery element for a motor vehicle, said element comprising: • a padding block made of elastically compressible, porous material, said block having a face for receiving an occupant of said seat, said block being provided with a cavity having an opening leading to said receiving face, • a rigid plate fixed at its periphery, by means of a decoupling means, at the periphery of said opening so as to obscure it, said plate having an inner face turned towards said cavity, • an inertial electrodynamic transducer comprising a coil and a magnet fixed on a support, said support being mounted by means of a suspension system attached to said coil, such that said plate vibrates when said transducer is powered, said coil being fixed on said inner face,
[0012] said element further having the following characteristics: • it further comprises a sealed acoustic insulation wall disposed over the entire external surface of said block, so as to channel the passage of acoustic waves from said transducer through said opening, said wall having a receiving portion extending opposite said receiving face, the remainder of said wall forming a complementary part of said receiving portion, • the material of said receiving part is elastically compressible, its shore hardness being less than 25 shore A and its Young’s modulus in compression being less than 5 MPa.
[0013] It is specified here that when it is said that the airtight acoustic insulation wall is arranged over the entire external surface of the block, it should be understood that said wall does not extend over the opening of the cavity.
[0014] With the proposed arrangement, the presence of the airtight acoustic insulation wall arranged over the entire external surface of the block makes it possible to channel the passage of acoustic waves from said transducer through the opening, in other words to close the "acoustic loading cavity".
[0015] Furthermore, the use of a material such as defined above to make the receiving part is conducive, due to the flexibility of said material, to the optimization of the comfort of a seat occupant.
[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 schematic cross-sectional view of an embodiment of a seat back provided with two upholstery elements arranged laterally on either side,
[0018] [Fig.2] is a detail view of [Fig.1],
[0019] [Fig.3] is a schematic cross-sectional view of a transducer according to one embodiment, said transducer being fixed on a plate.
[0020] With reference to the figures, a motor vehicle seat upholstery element 1 is described, said element comprising: • a block 2 of padding made of elastically compressible, porous material, said block having a receiving face 3 for an occupant of said seat, said block being provided with a cavity 4 having an opening 5 leading to said receiving face, • a rigid plate 6 fixed at its periphery, by means of a decoupling means 7 - for example in the form of a rubber or flexible foam seal -, at the periphery of said opening so as to obscure it, said plate having an inner face 8 facing said cavity, • an inertial electrodynamic transducer 9 comprising a coil 10 and a magnet 11 fixed on a support 12 - in particular made of molded plastic material -, said support being mounted by means of a suspension means 13 integrally to said coil, so that said plate vibrates when said transducer is powered, said coil being fixed on said inner face,
[0021] said element further having the following characteristics: • it further comprises a soundproof wall 17 arranged over the entire external surface of said block - said wall being for example glued to said block or inserted between said block and a cap as described later - so as to channel the passage of acoustic waves from said transducer through said opening, said wall having a receiving part 14 extending opposite said receiving face, the remainder of said wall forming a complementary part 15 of said receiving part, • the material of said receiving part is elastically compressible, its shore hardness being less than 25 shore A and its Young’s modulus in compression being less than 5 MPa.
[0022] The Shore A hardness measurement is notably carried out according to ISO 7619-1.
[0023] According to various embodiments, the material of the supplementary part 15 is optional: • identical to that of the receiving section 14, • or partly identical to that of said receiving part and partly different – for example, being based on thermoplastic elastomer – from that of said receiving part, • or different - being for example based on thermoplastic elastomer - from that of said receiving part.
[0024] According to one embodiment, the receiving part 14 has a thickness between 1 and 20 mm, so as to ensure a suitable level of comfort for a seat occupant.
[0025] According to one embodiment, the material of the receiving part 14 is a closed-cell foam.
[0026] According to one embodiment, the foam forming the material of the receiving part 14 has a density between 100 and 1500 kg / m3.
[0027] According to an embodiment not shown, the padding block 2 provided with the sealing wall 17 is covered at least in part by a covering cap - for example based on textile or leather provided with a soft foam underlayer - said cap having, at least opposite the plate 6, a resistance to the passage of air less than 200 Nsrn3, so as to allow the propagation of acoustic waves.
[0028] According to the embodiment shown, the plate 6 is covered with a layer of comfort foam 16 with a resistance to air passage of less than 200 Nsrn3, so as to allow the propagation of acoustic waves; such a layer of comfort foam 16 can in particular be inserted between the plate 6 and a cap as described above.
[0029] According to one embodiment, the padding block 2 is made of molded foam - in particular polyurethane - with a density between 30 and 80 kg / m3.
Claims
Demands
1. Component (1) of motor vehicle seat upholstery, said component comprising: • a block (2) of padding made of elastically compressible, porous material, said block having a receiving face (3) for an occupant of said seat, said block being provided with a cavity (4) having an opening (5) leading to said receiving face, • a rigid plate (6) fixed at its periphery, by means of a decoupling means (7), at the periphery of said opening so as to obscure it, said plate having an inner face (8) facing said cavity, • an inertial electrodynamic transducer (9) comprising a coil (10) and a magnet (11) fixed on a support (12), said support being mounted by means of a suspension means (13) integrally to said coil, so that said plate vibrates when said transducer is powered, said coil being fixed on said inner face, said element being characterized in that: • it further comprises a sealed acoustic insulation wall (17) arranged over the entire external surface of said block, so as to channel the passage of acoustic waves from said transducer through said opening, said wall having a receiving portion (14) extending opposite said receiving face, the remainder of said wall forming a complementary portion (15) of said receiving portion, • the material of said receiving part is elastically compressible, its shore hardness being less than 25 shore A and its Young’s modulus in compression being less than 5 MPa.
2. Element (1) according to claim 1, characterized in that the material of the complementary part (15) is optional: • identical to that of the receiving section (14), • or partly identical to that of said receiving part and partly different from that of said receiving part, • or different from that of said receiving part.
3. Element (1) according to any one of the preceding claims, characterized in that the receiving part (14) has a thickness between 1 and 20 mm.
4. Element (1) according to any one of the preceding claims, characterized in that the material of the receiving part (14) is a closed-cell foam.
5. Element (1) according to the preceding claim, characterized in that the foam forming the material of the receiving part (14) has a density between 100 and 1500 kg / m3.
6. Element (1) according to any one of the preceding claims, characterized in that the padding block (2) provided with the airtight wall (17) is covered at least in part by a covering cap, said cap having, at least opposite the plate (6), a resistance to air passage of less than 200 Nsm 3, so as to allow the propagation of acoustic waves.
7. Element (1) according to any one of the preceding claims, characterized in that the plate (6) is covered with a layer of comfort foam (16) with an air resistance of less than 200 Nsm3, so as to allow the propagation of acoustic waves.
8. Element (1) according to any one of the preceding claims, characterized in that the padding block (2) is made of molded foam with a density between 30 and 80 kg / m3.