WO2024218343A1

WO2024218343A1 - Glazing unit for transmitting and/or receiving a vibro-acoustic wave

Info

Publication number: WO2024218343A1
Application number: PCT/EP2024/060803
Authority: WO
Inventors: Shuibao Qi; Xuejuan XU
Original assignee: Saint-Gobain Glass France
Priority date: 2023-04-20
Filing date: 2024-04-19
Publication date: 2024-10-24
Also published as: FR3147985A1

Abstract

The present invention relates to a vehicle glazing unit suitable for vibro-acoustic transmission and/or reception, the glazing unit comprising an electromechanical transducer and a glazed assembly, the transducer being fixedly mounted on the glazed assembly, the transducer comprising a moving element, the glazing comprising a first cavity formed at least by a first wall, the moving element comprising an attachment portion and a moving portion, the attachment portion being fixedly mounted on the glazed assembly and the moving portion forming a suspended free membrane, the free membrane forming the first wall.

Description

glazing for emission and/or reception of a vibro-acoustic wave

Field of invention

The present invention relates to the field of vehicle glazing, and particularly glazing adapted to emit or receive acoustic waves.

State of the art

It is known to use vehicle glazing as an acoustic transducer. For this purpose, document WO202189457 describes glazing, for example forming the roof of a motor vehicle, comprising an exciter. The glazing is used as a membrane that can be set in motion by the exciter so as to emit acoustic waves. Thus, it is possible to reduce the weight and volume of the acoustic equipment compared to existing equipment and, in particular, to replace a subwoofer traditionally installed in a motor vehicle. However, such glazing forming an acoustic transducer does not have a satisfactory acoustic spectrum in the medium and high frequencies, i.e. for frequencies above 500 Hz. Traditional acoustic transducers, i.e. not integrated into the glazing, must supplement the vehicle's acoustic equipment to allow satisfactory restitution or capture of an acoustic wave in the passenger compartment of the vehicle.

One aim of the invention is to propose a solution for capturing or restoring vibro-acoustic waves in the passenger compartment of a vehicle at least in the audible frequency range.

This aim is achieved, at least partially, within the framework of the present invention by means of a vehicle glazing adapted for vibro-acoustic emission and/or reception, comprising an electromechanical transducer and a glazed assembly, the transducer being fixedly mounted on the glazed assembly, the transducer comprising a movable element, the glazing comprising a first cavity formed at least by a first wall, the movable element comprising a fixing part and a movable part, the fixing part being fixedly mounted on the glazed assembly and the movable part forming a suspended free membrane, the free membrane forming the first wall.

The present invention is advantageously supplemented by the following features, taken individually or in any of their technically possible combinations:

– the transducer comprises a fixing element, the fixing element being fixedly mounted to the glass assembly, the fixing portion being fixedly mounted to the fixing element, the first cavity also being formed by a side wall, the side wall being formed by the fixing element,

- the fixing part is in direct contact with the glass assembly,

- the first cavity is also formed by a second wall, the glazed element forming the second wall, the second wall being arranged opposite the first wall relative to the first cavity,

- the first cavity is a closed cavity,

- the fixing element is formed by a first layer and by a second layer, the fixing part being interposed between the first layer and the second layer, the first layer being fixedly mounted on the glazed assembly,

- the first layer is formed by a material having a modulus of elasticity E between 100 MPa and 10 GPa,

- the second layer forms a second cavity, preferably open, the free membrane forming a wall of the second cavity,

- the free membrane has a convex shape,

- the movable element comprises a piezoelectric layer, the piezoelectric layer being formed by a piezoelectric polymer, preferably by polyvinylidene fluoride,

- the movable element comprises two electrically conductive layers, the piezoelectric layer being arranged between the two electrically conductive layers,

- the piezoelectric layer and the two electrically conductive layers form the assembly of the fixed part(s) and the moving part(s) of the moving element,

- the glazed element comprises an opaque part, the opaque part preferably comprising a layer of enamel, the transducer being fixedly mounted on the opaque part,

– the glazing includes a network of transducers,

- at least two free membranes of two transducers have different diameters,

- each transducer comprises a fixing element, the fixing element being fixedly mounted to the glazed assembly, the fixing part of each transducer being fixedly mounted to the fixing element of each transducer, each first cavity also being formed by a side wall of each transducer, the side wall being formed by the fixing element of each transducer, each fixing element being formed by the same first layer and by the same second layer, each fixing part being arranged between the first layer and the second layer, the first layer forming side walls of the first cavities of each of the transducers,

- a diameter of each free membrane is between 10 µm and 10 mm, preferably between 500 µm and 5 mm,

- the glazing forms an element chosen from a vehicle windshield, a vehicle roof, a vehicle side window and a vehicle rear window,

– the glazing comprises a control unit configured to apply and/or measure an electrical voltage between the two electrically conductive layers.

Another aspect of the invention is a method of manufacturing glazing according to an embodiment of the invention, comprising a step of embossing the movable element by applying a layer against a mold having a concave part, then by suctioning a part of the layer into the concave part so as to form a convex movable part.

Another aspect of the invention is a method of vibro-acoustic emission and/or reception implemented by glazing according to an embodiment of the invention, the method comprising a step of applying and/or measuring an electrical voltage between the two electrically conductive layers.

Description of figures

Other characteristics, aims and advantages of the invention will emerge from the description which follows, which is purely illustrative and non-limiting, and which must be read in conjunction with the appended drawings in which:

- there schematically illustrates a glazing according to an embodiment of the invention comprising a network of transducers,

- there schematically illustrates a free membrane of a transducer according to an embodiment of the invention,

- there schematically illustrates a transducer network according to an embodiment of the invention in top view,

- there schematically illustrates a motor vehicle roof according to one embodiment of the invention,

- there schematically illustrates a motor vehicle windshield according to one embodiment of the invention,

- there schematically illustrates a glazing according to an embodiment of the invention in which the transducer is integrated inside a laminate,

- there schematically illustrates glazing according to an embodiment of the invention in which the transducer is integrated inside a laminate.

In all figures, similar elements bear identical references.

Definitions and measurements

The modulus of elasticity E of a material, or Young's modulus, can be measured by the international standard ASTM E111.

By " convex ", when characterizing the shape of a membrane, is meant that the membrane has a shape extending along a surface forming a spherical curvature and extending on the side opposite the glazed assembly relative to the plane defined by the periphery of the membrane.

“ Opaque part ” means a part of a glazing having a light transmission coefficient of less than 5%, in particular less than 1%.

The term “ transparent part ” of a glazing means a part having a light transmission coefficient greater than 30%, preferably greater than 50%, in particular greater than 70%.

Direct mounting of two elements to each other means that the two elements are in contact or connected by an adhesive layer. The adhesive may be a transparent optical glue. In the case of contact between the two elements, one of the elements may be connected to the other by electrostatic forces.

" Vibro-acoustic waves " means a set of waves formed by acoustic waves, propagated by a fluid, and/or by vibratory waves, which are propagated by a solid.

Detailed description of the invention

Description générale de l’architecture du vitrage 1General description of the glazing architecture 1

In reference to the , to the , to the , and to the , one aspect of the invention is a vehicle glazing 1 adapted for vibro-acoustic emission and/or reception. The glazing 1 comprises at least one electromechanical transducer 2 and a glazed assembly 3. The transducer 2 is fixedly mounted on the glazed assembly 3. The transducer 2 comprises a movable element 4. The movable element 4 comprises a fixing part 7 and a movable part 8. The fixing part 7 is fixedly mounted to the glazed assembly 3. This mounting can be direct or indirect. In the case of indirect mounting, a fixing element can make it possible to fixedly mount the fixing part 7 to the glazed assembly 3. The movable part 8 forms a suspended free membrane. The movable part 8 is adapted to emit and/or receive a vibro-acoustic wave. The glazing 1 comprises a first cavity 5. The cavity 5 is formed at least by a first wall 6. The free membrane forms the first wall 6. Thus, it is possible to integrate into the glazing a transducer 2, adapted for vibro-acoustic emission and/or reception, comprising a membrane whose size is independent of the size of the glazing. This makes it possible to adapt the transducer 2 to a predetermined frequency range independent of the size of the glazed assembly.

The glazing 1 may form an element selected from a vehicle windshield, a vehicle roof, a vehicle side window and a vehicle rear window. In particular, the glazing 1 may comprise a transducer 2 arranged on a transparent part of the glazed assembly 3, the glazing 1 being a vehicle side window or roof.

In reference to the , the transducer 2 may comprise a fixing element 10. The fixing element 10 is fixedly mounted to the glazed assembly 3. The fixing part 7 is fixedly mounted to the fixing element 10. The first cavity 5 is formed, in addition to a first wall, by a side wall 11. The side wall 11 is formed by the fixing element 10. Thus, it is possible to fixedly mount the movable element 4 to the glazed assembly 3 while choosing the geometry of the cavity 5, which makes it possible to increase the efficiency of the vibro-acoustic emission and/or reception of the glazing 1.

In reference to the , the fixing element 10 can form both a side wall 11 and a second wall of the cavity 5, the second wall being opposite the first wall with respect to the cavity 5.

In reference to the , the fixing part 7 can be in direct contact with the glass assembly 3. Thus, the thickness of the transducer 2 can be minimized.

In reference to the , the first cavity 5 can also be formed by a second wall 12 formed by the glazed element 3. The second wall 12 can be arranged opposite the first wall 6 relative to the first cavity 5. Thus, it is possible to simplify the manufacture of the cavity 5 by using a fixing element 10 comprising an opening between the movable part 8 and the glazed element 3.

The cavity 5 may be a closed cavity. Alternatively, a glazing 1, comprising a plurality of transducers 2, comprises a plurality of cavities 5 which may form a closed assembly. By “ closed ”, it is meant that there is no passage arranged between the cavity(ies) and the exterior of the glazing 1. Thus, an acoustic resonance caused by a cavity 5 can be controlled.

Elément de fixation 10Fastening element 10

The fixing element 10 may be formed by a first layer 13 and, preferably, by a second layer 14. The first layer 13 is fixedly mounted on the glazed assembly 3. The fixing part 7 may be fixedly mounted on the first layer 14. Preferably, the fixing part 7 is interposed between the first layer 13 and the second layer 14.

The first layer 13 may be formed by a material having a modulus of elasticity E of between 100 MPa and 10 GPa. Thus, the efficiency of the emission and/or reception of a vibro-acoustic wave by the movable part 8 may be increased with respect to a glazing in which the fixing part 7 is fixedly mounted to the glazed element 3 directly or by means of a part formed by a more rigid material. In particular, the inventors have surprisingly discovered that the efficiency of the emission and/or reception of a vibro-acoustic wave by the movable part 8 is greater for this range of rigidity of the material with respect to the efficiency for rigidities greater than 10 GPa. For a material rigidity lower than the rigidities of the previously defined range, interferences between the mobility of the mobile part 8 and the fixing part 7 may appear during the use of the glazing 1, which leads to a deterioration in the efficiency of the transducer formed by the mobile part 8. The first layer 13 may be formed for example from polyethylene terephthalate (PET), having a modulus of elasticity between 2800 MPa and 3100 MPa.

The second layer 14 can form a second cavity 15. The second cavity 15 is preferably open. The free membrane forms a wall of the second cavity 15. Thus, the free membrane is protected from external mechanical aggression by the second layer 14.

Elément mobile 4 Mobile element 4

The movable element 4 comprises a movable part 8 which forms the free membrane. The free membrane allows the transduction of a vibro-acoustic wave. The free membrane is preferably convex in shape. Thus, the membrane is suitable for emitting or receiving vibro-acoustic waves having medium or high frequencies, preferably frequencies greater than 500 Hz.

One aspect of the invention is a method for manufacturing the glazing 1. The method comprises a step of embossing the movable element 4 by applying a layer against a mold having a concave portion, then by suctioning a portion of the layer into the concave portion so as to form a convex movable portion 8. The movable element 4 is fixedly mounted to the glazed element 3 during a subsequent step. Thus, it is possible to form a convex movable portion 8 on a portion of an initially flat layer from a predefined geometry. In the case of a glazing unit comprising a plurality of transducers 2, it is possible to form all of the convex movable portions 8 in a single step by suction.

In reference to the , the movable element 4 may comprise a piezoelectric layer 16. The piezoelectric layer 16 may be formed by a piezoelectric polymer. The piezoelectric polymer may be selected from polyvinylidene fluoride (PVDF), polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE) and a ferroelectric polymer.

The movable element 4 may comprise two electrically conductive layers 17. The piezoelectric layer 16 may be arranged between the two electrically conductive layers 17. Thus, it is possible to actuate the membrane without using an actuator external to the movable element 4.

One aspect of the invention is a method of vibro-acoustic emission and/or reception implemented by a glazing 1. The method comprises a step of applying and/or measuring an electrical voltage between the two electrically conductive layers 17. Thus, it is possible to control the vibrations of the free membrane, and/or to measure the vibrations of the free membrane.

Réseau de transducteurs 2 Transducer network 2

In reference to the , the glazing 1 may comprise an array of transducers 2. At least two free membranes of two different transducers 2 may have different diameters. Thus, the glazing 1 may be adapted to emit and/or receive vibro-acoustic waves over a wider frequency range than the frequency range of known glazings. At least one free membrane may have a diameter of less than 2 mm, preferably less than 1 mm. Thus, the transducer 2 is adapted to emit and/or receive vibro-acoustic waves in the medium or high frequencies. For example, some of the diameters may be adapted to low frequencies, other diameters to medium frequencies, and other diameters to high frequencies. The different diameters of the free membranes may be chosen according to a Fibonacci growth. Preferably, a diameter of each free membrane is between 10 µm and 10 mm, in particular between 500 µm and 5 mm. Thus, the glazing 1 may comprise a network of transducers 2 arranged on a portion of the glazing 1 having a surface area of less than 10% of the total surface area of the glazing 1, preferably less than 5% of the total surface area of the glazing 1.

The first layer 13 can form all of the side walls 11 of the first cavities 5. Thus, the manufacture of the transducer array 2 can be simplified. The manufacture of the transducer array 2 can comprise a step of forming a plurality of openings, so as to form the side walls 11 of the first cavities 5. Alternatively, the manufacture of the transducer array 2 can comprise a step of molding, for example by embossing, the first layer 13, without forming an opening through the first layer 13, and so as to form the side walls 11 of the first cavities 5.

Dissimulation des transducteurs 2Concealing the transducers 2

In reference to the and to the , the glazed element 3 may comprise an opaque part 18. The opaque part 18 may comprise a layer of enamel. The transducer(s) 2 may be fixedly mounted on the opaque part 18. Thus, the transducer(s) 2 do not obstruct the user's field of vision through the glazing 1.

Elements forming the transducer 2 may be transparent. Preferably, the first layer 13 and the movable element 4 may be transparent. A thickness of the first layer 13 may be chosen such that the light transmission coefficient through the first layer 13 is greater than 5%, preferably greater than 10%, preferably greater than 20%. For example, the first layer 13 may be formed of PET and have a thickness of 50 µm. The second layer 14 may be formed of PET and have a thickness of 30 µm. The piezoelectric layer 16 may be formed of PVDF. The thickness of a piezoelectric layer 16 formed of PVDF may be less than 80 µm, in particular less than 50 µm. The electrically conductive layers 17 may be formed of indium tin oxide (ITO). Thus, it is possible to arrange the transducer(s) 2 on a transparent part of the glass assembly 3 without obstructing the field of vision of the user of the glazing 1.

In reference to the and to the , the glazing 1 may comprise another glazed assembly 3 and an interlayer 21, preferably a viscoelastic interlayer. The viscoelastic interlayer 21 is arranged on the glazed assembly 3. The viscoelastic interlayer 21 may comprise an opening, in which the transducers 2 are mounted. The other glazed assembly 3 may be mounted on the viscoelastic interlayer 21 and on the set of transducers 2 so as to form a laminated glazing 1 in which the transducers 2 are integrated. With reference to the , an opening may be formed in the glazed assembly 3 mounted on the viscoelastic interlayer 21 and on the transducers 2 above the transducers 2. Thus, it is possible to have a passage between the free membrane and the outside of the glazing 1. The glazing 1 may be used to measure vibrations and/or acceleration of the glazing 1. The glazing 1 may also be used to facilitate the removal of raindrops or snowflakes deposited on an outer face of a glazed assembly 3. The transducers 2 may cause vibrations for this purpose. Finally, the glazing 1 may allow easier cleaning of one of the outer faces of one of the glazed assemblies 3. Indeed, the vibrations caused by the transducer(s) 2 may facilitate such cleaning.

Claims

Vehicle glazing (1) adapted for vibro-acoustic transmission and/or reception, comprising an electromechanical transducer (2) and a glazed assembly (3), the transducer (2) being fixedly mounted on the glazed assembly (3), the transducer (2) comprising a movable element (4),
characterized in that the glazing (1) comprises a first cavity (5) formed at least by a first wall (6), the movable element (4) comprising a fixing part (7) and a movable part (8), the fixing part (7) being fixedly mounted to the glazed assembly (3) and the movable part (8) forming a suspended free membrane, the free membrane forming the first wall (6).
Glazing (1) according to claim 1, wherein the transducer (2) comprises a fixing element (10), the fixing element (10) being fixedly mounted to the glazed assembly (3), the fixing portion (7) being fixedly mounted to the fixing element (10), the first cavity (5) also being formed by a side wall (11), the side wall (11) being formed by the fixing element (10).
Glazing (1) according to claim 1, in which the fixing part (7) is in direct contact with the glazed assembly (3).
Glazing (1) according to claim 1, in which the first cavity (5) is also formed by a second wall (12), the glazed element (3) forming the second wall (12), the second wall (12) being arranged opposite the first wall (6) relative to the first cavity (5).
Glazing (1) according to one of the preceding claims, in which the first cavity (5) is a closed cavity.
Glazing (1) according to one of the preceding claims, in which the fixing element (10) is formed by a first layer (13) and by a second layer (14), the fixing part (7) being interposed between the first layer (13) and the second layer (14), the first layer (13) being fixedly mounted on the glazed assembly (3).
Glazing (1) according to the preceding claim, in which the first layer (13) is formed by a material having a modulus of elasticity E of between 100 MPa and 10 GPa.
Glazing (1) according to the preceding claim, in which the second layer (14) forms a second cavity (15), preferably open, the free membrane forming a wall of the second cavity (15).
Glazing (1) according to one of the preceding claims, in which the free membrane has a convex shape.
Glazing (1) according to one of the preceding claims, in which the movable element (4) comprises a piezoelectric layer (16), the piezoelectric layer (16) being formed by a piezoelectric polymer, preferably by polyvinylidene fluoride.
Glazing (1) according to the preceding claim, in which the movable element (4) comprises two electrically conductive layers (17), the piezoelectric layer (16) being arranged between the two electrically conductive layers (17).
Glazing (1) according to one of the preceding claims, in which the glazed element (3) comprises an opaque part (18), the opaque part (18) preferably comprising a layer of enamel, the transducer (2) being fixedly mounted on the opaque part (18).
Glazing (1) according to one of the preceding claims, comprising a network of transducers (2).
Glazing according to claim 13, in which at least two free membranes of two transducers (2) have different diameters.
Glazing (1) according to the preceding claim, in which each transducer (2) comprises a fixing element (10), the fixing element (10) being fixedly mounted to the glazed assembly (3), the fixing part (7) of each transducer (2) being fixedly mounted to the fixing element (10) of each transducer (2), each first cavity (5) also being formed by a side wall (11) of each transducer (2), the side wall (11) being formed by the fixing element (10) of each transducer (2), each fixing element (10) being formed by the same first layer (13) and by the same second layer (14), each fixing part (7) being arranged between the first layer (13) and the second layer (14), the first layer (13) forming side walls (11) of the first cavities (5) of each of the transducers (2).
Glazing (1) according to one of the preceding claims, in which a diameter of each free membrane is between 10 µm and 10 mm.
Glazing (1) according to one of the preceding claims, forming a vehicle windshield or a vehicle roof.
Glazing (1) according to one of claims 11 to 17, comprising a control unit (19) configured to apply and/or measure an electrical voltage between the two electrically conductive layers (17).
Method (100) for manufacturing glazing (1) according to one of claims 9 to 18, comprising a step of embossing the movable element (4) by applying a layer against a mold having a concave part, then by suction of a part of the layer into the concave part so as to form a convex movable part (8).
Method (200) of vibro-acoustic emission and/or reception implemented by a glazing (1) according to one of claims 1 to 18, the method (200) comprising a step of applying and/or measuring an electrical voltage between the two electrically conductive layers (17).