MXPA98008233A - Fixed glass of improved acoustic protection in contact with a periper gasket - Google Patents

Abstract

The present invention relates to: A window pane fixed to a vehicle through a peripheral joint and forming at least a part of a wall defining a vehicle cabin, wherein the window pane, at the peripheral junction, comprises means for locally modifying the window pane at the peripheral junction to eliminate at least one mode of acoustic radiation from the window pane to a cavity defined by the cabin when the window pane is excited by an acoustic field.

Description

FIXED GLASS OF IMPROVED ACOUSTIC PROTECTION IN CONTACT WITH A PERIPHERAL GASKET DESCRIPTION OF THE INVENTION The invention relates to a fixed acoustic protection glazing improved for vehicle and particularly for automotive vehicle, in contact with a peripheral joint. Through all the qualities that concern comfort in modern means of transport such as trains and automobiles, silence becomes decisive. In effect, the other sources of disintegration of mechanical, thermal, visibility, etc. origin have been almost dominated. However, the improvement of acoustic comfort presents new difficulties. Noises of aerodynamic origin, that is, created by the friction of the air with the vehicle in motion, can be treated, at least in part, from its origin. That is, to save energy, shapes were modified, air penetration was improved and the turbulence that is the origin of noise was reduced. Between the body of a vehicle that separates the origin of the exterior aerodynamic noise, the interior space where the passenger is, the glasses are obviously the most difficult to deal with. It is not possible to use two pasty or fibrous absorbents reserved in the opaque bodies, and for reasons of weight, the thicknesses can not be increased in an inconsiderable manner. European patent EP-B1-0 387 148 proposes glasses that perform a good insulation against noise of aerodynamic origin without their weight and / or their thickness being increased too much. The patent also proposes a laminated glass where the intercalation contains good damping properties. Therefore, the noise itself, such as engine noise, rolling noise or suspension noise, must be treated at the same time. Such noises have already been treated from their origin or, in part in the course of their propagation, either air (absorbing coating in particular) or in solids (junction pieces in elastomer for example). In contrast, the treatment of glass against noise that originates in the vehicle itself, that is, noise transmitted by air or through solids, is more difficult to carry out and is not yet fully dominated till the date. Glasses constitute an important area of the vehicle's cabin, and consequently, an important radiation surface. It is proved that the use of the adapted connecting pieces are insufficient to prevent the propagation of noise by means of the vibration of the glasses and that in particular at certain speeds of rotation of the engine, a sound perceptible by the passenger also seems to be the cause from a source of disagreement. In effect, the rotation of the motor leads to a creation of vibrations that are transmitted to the glass by air or through solids. The main parameters that influence the vibro-acoustic behavior of glasses in this domain reside in the shape of the glass, in its structure, in the glass / cabin interface, in the exciter source and in the propagation mode. Similarly, for a given vehicle, the action parameters to improve the behavior of the radiation panel that constitute the glasses that are in the glass structure, as well as the glass / cabin interface. Several efforts have been made in the structure of the glass in order to improve the effect of sound reduction inside the cabin. One can cite in a general way the production of laminated glass where the interlayer has original properties that give the glasses a good protection against aerodynamic noise and / or noise of air origin and / or noise of solid origin as well as the realization of multiple glasses. In contrast, the use of such glasses in the bodywork of a vehicle considerably increases the cost of the vehicle. The invention is provided for the task of supplying a fixed glass in contact with a peripheral joint for a vehicle in particular, for a motor vehicle having good acoustic protection against noise, in particular against noise of air origin and of solid origin and without thereby considerably increasing the cost of the vehicle. Such an objective is achievable according to the invention for a fixed glass in contact with a peripheral joint for vehicle and particularly for automotive vehicle, such glass is provided at least with radiation modes which are coupled with a variety of cavity modes of the vehicle cabin until such a glass is excited by an acoustic field. Acoustic field is understood as the union of vibrations created by the aerial and solid propagation of noise. The structure of the glass is not limited to monolithic glasses, all types of laminated glass and multiple crystals also fall within the scope of the invention, in the same way that glass is not a limiting parameter of the invention, all possible forms for a fixed glass intended for a vehicle that enters the field of the invention. The fixed glass according to the invention makes it possible to reduce the buzz effect perceptible by the passenger at certain speeds of rotation of the engine, thanks to the elimination of the radiation modes that are coupled with the cavity modes of the vehicle cabin. Indeed, at certain frequencies of engine vibrations *, at certain speeds of rotation of the engine, the windows and the vehicle cabin have radiation and cavity modes where the coupling amplifies the hum of noise radiation coming from the juncture of the engine by the crystals. Likewise, by eliminating such radiation modes, the amplified effect of the buzz is eliminated and the passenger's acoustic comfort is increased. A modal analysis of the vehicle cabin allows determining the frequency with which the effect of the buzzing caused by the coupling of a radiation mode of a vehicle glass with a cavity mode of the cabin appears. For this reason, an assembly is made in engine mode the vehicle relay the curve of the cavity modes of the cabin volume. The frequency called "bothersome" appears due to the formation of an important peak with an accuracy of the order of + 5%. Thanks to the fixed glass according to the invention, it is possible to eliminate the so-called "annoying" radiation mode. According to a variant of the invention, the fixed crystal is devoid of at least a first odd radiation mode. For odd mode, the number of radiation zones is defined and, on the other hand, the even number of radiation zones is defined by even mode. In this way, a single radiation zone is defined by the first odd mode. In this way while the glass according to the invention exists by an acoustic field which has at least two radiation zones.

According to the invention, the fixed crystals make it possible to reduce the elimination of the first odd radiation mode in order to reduce the radiation to the crystal. In effect, the first odd mode is the way to increase the rays made of noise from the single radiation zone. In this way, the elimination of the radiation mode diminishes the overall glass radiation by the presence of at least two radiation zones. According to a preferred embodiment of the invention, the fixed crystal is devoid of all odd modes of radiation until they are excited by an acoustic field. In this way, the crystal is excited by an acoustic field, it has an even number of radiation zones, that is, of radiation zones in phase opposition. The fixed glass according to the invention allows to reduce the overall radiation * of the crystal thanks to the radiation zones in phase opposition. In effect, the lag of the zones allows to obtain an effect of compensation of the zones among themselves. Graphically, while one zone pulls to one side, the other zone pushes in the reverse direction, so that the vibrational effect of the sum of the zones that is either a null effect and the active radiation is greatly diminished. By decreasing the radiation, the transmission of noise is reduced and the acoustic comfort inside the cabin is improved accordingly. According to the preferred embodiment of the fixed glass according to the invention, the crystal displacement in the peripheral joint is locally decreased. The inventors show that by locally modifying the fixed glass / cabin connection at the level of the peripheral joint, a modification of the crystal radiation is carried out and in particular a decrease in radiation can be realized. In this way, the reduction of the displacement of the crystal in the peripheral joint only in a limited part of the periphery of the crystal makes it possible to make a crystal devoid of at least one first odd mode of radiation until it is excited by an acoustic field. For each well-defined type of crystal, it is necessary to determine the zone (s) of the crystal where the displacement in the peripheral joint will decrease. For this reason, a series of measurements is made according to which one or several wedges are distributed along the periphery of the glass between the peripheral joint and the edge of the glass, the displacement being ordered according to a pitch of 5 cm and for each position of the wedges the radiation modes of the crystal are raised from a modal analysis. Similarly, the curves make it possible to determine for which positions of the wedges such a crystal is devoid of radiation mode called "annoying" until they are excited by an acoustic field. Accordingly, with one embodiment of the invention, the fixed window has at least one point of transparency at the level of its contact with the peripheral seal. By point of transparency is meant a strut deformation of the crystal. Such a puncture deformation allows to locally increase the conservation of the glass in the peripheral joint that oppresses it, decreasing the possibility of displacement accordingly. According to another embodiment of the invention, the fixed glass has at least one overweight at the level of its contact with the peripheral seal. Such overweight of the crystal can be carried out by any means known to the skilled person by means of the aid of a tablet which is placed on the edge of the glass, for example, by encapsulation or extrusion, or with the help of a peripheral frame of the glass. glass where the thickness varies along. Any other means that aims to perform an overweight of the crystal at the level of its contact with the peripheral seal within the scope of the invention. The function of such local overweight is identical to that of the transparency point. According to the other embodiments of the invention, the peripheral seal has at least one clip or clasp that comes into contact with the fixed glass. A clip or snap means any element that can be integrated into a joint and exerts a compressive force on the upper pane of the joint. SimilarlyThanks to its elements, the preservation of the glass in the peripheral joint is increased locally. The integration of such elements in the peripheral joint can be carried out by all means known to the person skilled in the art. According to another embodiment of the invention, the peripheral seal is forged at least a part of its length. Forcing means the fact of modifying the joint in at least a part of its length so that its contact with the glass is modified, as well as the displacement of the glass in the joint is not identical throughout the length of the joint. Preferably, forcing is understood to locally increase the pressure forces exerted by the peripheral seal on the edge of the glass and thus locally increase the preservation of the glass in the glue. The invention also relates to a peripheral joint designed to receive an improved acoustic protection fixed glass for vehicles and particularly for motor vehicles. According to the invention, such a peripheral seal locally decreases the displacement of the fixed glass in contact with it. A local decrease in the displacement of the fixed crystal in the joint makes it possible to define the radiation of the crystal thanks to the suppression of at least the first odd radiation mode. In accordance with one embodiment of the invention. The peripheral joint presents a differentiated rigidity. In this way, the displacement of the fixed glass in the joint is modified, which is identical to the entire length of the joint and the radiation of the glass is modified.

According to another embodiment of the invention, a clip or clasp is fixed on the peripheral joint and is in contact with the glass until it is placed on the joint. The clip then exerts a pressure on the fixed glass and decreases the displacement of the glass. The fixed glass according to the invention has good acoustic protection against noise and in particular noise of air origin and solid origin. The fixed glass according to the invention as well as the peripheral seal according to the invention make it possible to substantially improve the effect of sound weakening of the glass in consequence and where the comfort in the vehicle is, so that it is well known that it increases the capacity of the glass. concentration of duct and diminishes its wear. In such a way that the fixed glass and the peripheral seal activate safety in general in a "favorable manner." The description and the figures make it possible to understand the operation of the invention and take all the advantages In the Figures: Figure 1: represents the radiation from a classic car fixed side glass; Figure 2: represents the radiation of a fixed side window according to the invention; Figure 3: represents the edge of a fixed side window according to the invention; Figure 4: represents the edge of a crystal of yet another fixed side window according to the invention; Figure 5: represents the edge of a glass of a fixed side glass in contact with a peripheral joint according to the invention; FIGS. 1 and 2 respectively represent a fixed side window 1 and 2 of a car which is constituted of the two, for example of a monolithic glass soaked in thickness of 3 mm on the basis of sprinkling if only one or Calc co in contact with a peripheral joint 3, such crystal is excited by an acoustic field. The two figures allow to understand the acoustic improvement contributed by the invention. In Figure 1, the fixed side glass 1 in contact with the peripheral joint 3 shows the radiation of a conventional fixed crystal. Classical glass means a crystal that is generally found in current vehicles and is not limited to the invention. The fixed side window 1 excited by an acoustic field has a single radiation area 4. Such zone 4 is represented by several closed curves that are joined together. Such representation is equivalent to those level curves, the different levels corresponding to the displacements of the vibrations of the crystal. The symbol "+" represents the positive phase of radiation and the sign "-" in the following figure represents the negative phase. In this way, it is represented with the signs "+" and "-" the zones in opposition of phase. Figure 1 shows, thanks to the radiation zone 4, that the entire surface of the radiation crystal in phase, in fact, moves in the same way. In this way, the active radiation of the crystal encompasses the entire surface of the crystal. Figure 2, the fixed side glass 2 in contact with the peripheral joint 3 * shows the radiation of a fixed glass according to the invention. Two radiation zones 5 and 6 are observed in phase opposition replacing the radiation area 4. The curves represent the displacement, it is then understood that the zone 5 moves in one direction, the zone 6 moves in the opposite direction. In this way a compensation structure appears and the active radiation, which is strongly diminished in relation to that of figure 1. Thanks to such a decrease in active radiation, the transmission of noise is decreased, and then the weakening effect is improved sound inside the vehicle cabin. The representation to figures 1 and 2 are not given to the explanatory title and do not represent "any value of particular measurements. In effect, the presentations of measurements will have no interest for the description because such measurements are particular to each type of vehicle and to each fixed glass of such vehicles. Figures 3 and 4 represent the edge (7; 8) of a monolithic crystal (9; 10) of a fixed side window 2 according to the invention, such edge (7; 8) is brought into contact with a peripheral joint that does not represent. According to the representation of FIG. 3, the edge 7 of the crystal 9 has a point of transparency 11, that is to say a local deformation of the contour of the crystal. A point of transparency 11 can be obtained, for example with the aid of a pressure form up to the formation of the crystal, or with the aid of a differential blow over said area up to the formation or wetting of such crystal. The transparency point 11 preferably has a thickness of the order of a millimeter. In such a way that the glass 9 is in contact with the peripheral seal, the preservation of the glass 9 in the peripheral joint increases locally thanks to the point of transparency 11 which locally decreases the displacement of the crystal 9 in the peri-organic joint. According to the representation of FIG. 4, the edge 8 of the glass 10 has a local overweight 12, such an overweight 12 can be obtained, for example, by placing a plastic tablet, or in addition to screen printing a tin tablet on each crystal . Such pellets 12 preferably have the dimensions 5 mm × 10 mm × 1 mm. In such a way, as by "the point of transparency 11, the displacement of the crystal 10 in the peripheral joint is locally diminished. Figure 5 represents the edge 13 of a monolithic crystal 14 of a fixed side window, in contact with a peripheral joint 15 in which the radiation is punctually modified in order to decrease the lateral displacement of the fixed side window in contact with the joint peripheral 15. The peripheral joint 15 is made from a standard peripheral joint of a second mold that is usually found in the fixed windows of the vehicles. According to the representation of Figure 5, the peripheral seal 15 has an insert 16 submergible in thickness. An insert 16 has a greater hardness than that of the peripheral joint 15 and for example it is in a metal or a plastic. According to the representation, it integrates in the joint 15 in an outward manner to an outer cut of the joint 15, it can also be exposed to the edge of the glass or completely submerged in the thickness of the joint 15. The realization of such joint 15 comprises an insert 16 which presents no difficulty for the person skilled in the art; Prior to the invention of the material, the insert is positioned inside the mold or the edge of the glass so that it is in place during the injection of the material, then it is immersed in the hard material until the opening of the material. mold. In this way, the obtained joint makes it possible to decrease the lateral displacement of the crystal at the level of the insert 16. The invention is not limited to these types of embodiment, all types of fixed glass in contact with the peripheral seal are devoid of at least the modes of radiation which are coupled with one or more cavity modes of the vehicle cabin until the crystal is excited by an acoustic field, which enters the field of the invention. The advantages presented by the crystal according to the invention are manifested; in the acoustic protection that is significantly improved without it being necessary to modify the structure of all the glass surfaces of the vehicle, consequently decreasing the cost.

Claims (11)

1. An improved fixed acoustic protection glass for a vehicle and particularly for a motor vehicle, in contact with a peripheral joint, characterized in that the vehicle / cabin cockpit of the vehicle, at the level of the peripheral joint, is locally modified in a manner that the crystal is devoid of at least one of the radiation modes that are coupled with a variety of cavity modes of the vehicle cabin until the crystal is excited by an acoustic field.

2. The improved acoustic protection fixed glass according to claim 1, characterized in that the vehicle / vehicle cabin, at the level of the peripheral joint, is locally modified so that the glass is devoid of at least one first odd mold of radiation until it is excited by an acoustic field.

3. The improved fixed acoustic protection glass according to claim 1 or 2, characterized in that the glass / cabin connection of the vehicle, at the level of the peripheral joint, is locally modified so that the glass is devoid of all modes odd radiation until excited by an acoustic field.

4. The improved fixed acoustic protection glass according to one of claims 1 to 3, characterized in that the displacement of the glass in the peripheral joint is locally decreased.

5. The improved fixed acoustic protection glass according to claim 4, characterized in that the crystal has at least one point of transparency at the level of its contact with the peripheral joint.

6. The improved fixed acoustic protection glass according to claim 1, characterized in that the glass has at least one overweight at the level of its contact with the peri-gasket.

7. The improved fixed acoustic protection glass according to claim 4, characterized in that the peripheral seal has at least one clip or clasp that comes into contact with the glass.

8. The improved fixed acoustic protection glass according to claim 4, characterized in that the peripheral seal contracts at least a part of its length.

9. A peripheral joint designed to receive an improved fixed acoustic protection glass for a vehicle and particularly for a motor vehicle, characterized in that the seal locally decreases the displacement of the crystal.

10. The peripheral joint according to claim 9, characterized in that the joint has a differentiated rigidity.

11. The peripheral joint according to the rei indication 9, characterized by a clip or clasp is fixed and the board is in contact with the fixed glass.