Door leaf for passenger transport vehicle with improved sound insulation properties, door and vehicle with it

Description

Technical field of the invention

[0001] The present invention relates to the technical field of doors intended to equip passenger transport vehicles, in particular of the train, tram, metro or even trolleybus or bus type. The invention relates more specifically to such doors, which are provided with at least one leaf having improved acoustic insulation properties. State of the art

[0002] Typically, a door leaf for a passenger transport vehicle first comprises two facings, intended to be placed on the inner and outer sides of the vehicle body respectively. These facings thus delimit an internal space, which is occupied by a filling made essentially of a rigid material, glued to the facings, the whole forming a sandwich.

[0003] The technical problem, targeted more specifically by the present invention, is that of sound insulation on board passenger transport vehicles, of the aforementioned type. This problem is increasingly acute, particularly in view of the comfort requirements implemented on board these vehicles. For example, for mainline trains, it is now required that passengers wishing to make telephone calls use the access platforms. Under these conditions, it is understood that the leaves, equipping the train access doors, must have significant sound insulation properties.

[0004] We already know of doors with a structural thickness typically between 25 and 50 millimeters, whose sandwich core is glued and made from rigid foam or honeycomb. The use of this sandwich is a disadvantage in terms of acoustic performance. Indeed, this type of sandwich has an unsatisfactory weighted sound reduction index Rw, of the order of 25 to 32 dB according to the ISO 717-1 standard depending on the configuration.

[0005] To improve these acoustic performances, it has been proposed to increase the surface mass of the panel. To this end, for example, sheets of bituminous products are added to the sandwich described above, or the thickness or density of the facings is increased. Alternatively, a complete acoustic shell is used, decoupled from the structure.

[0006] This latter solution, however, has the following drawbacks. Indeed, to be truly effective, the acoustic shell must have a thickness of around 20 millimeters. The presence of this shell therefore requires reducing the thickness of the structural zone of the leaf, given that the total thickness of the latter must be substantially invariant. This has the effect of significantly increasing the mass of this leaf, to maintain the same behavior under mechanical stresses. In addition, the door thus produced presents the traveler with a non-structural surface. Consequently, the latter is more sensitive to the effects of punching, due for example to a suitcase blow.

[0007] Furthermore, noise barriers are known, placed in particular near road infrastructures in order to protect local residents from noise pollution. The teaching of these noise barriers cannot be transposed, in a simple manner, to a door leaf as targeted by the invention. Indeed, these walls are fixed, heavy and bulky constructions, the constituent materials and mechanical characteristics of which are not adapted to a leaf fitted to a mobile vehicle, most often moving at high speeds. Furthermore, in the case of a noise barrier, the noise to be attenuated is of external origin whereas, in the case of a vehicle leaf, the sound source is essentially generated by the actual movement of the vehicle.

[0008] In order to overcome the drawbacks detailed above, the applicant proposed, in French patent 3,072,333, to arrange the filling of the leaf in a specific manner. In essence, a filling body made of a rigid material is provided, as well as at least one block formed of an acoustic insulating material. This solution makes it possible to significantly reduce the noise pollution suffered by the passengers of the transport vehicle equipped with this leaf. Furthermore, the latter benefits from satisfactory mechanical behavior, in particular in terms of overall rigidity.

[0009] Also worth mentioning is document DE 10 2014 210771, which discloses an exterior door for a railway vehicle, the leaf of which is equipped with a thermal insulation material. Such material is in this case formed by a layer comprising an aerogel. The teaching of this document, which focuses essentially on the thermal aspect, is not promising in the context of the present invention, which is primarily aimed at the acoustic aspect.

[0010] Finally, we will mention document DE 699 36 046, which relates to a multi-layer sound insulation element, comprising external layers and a central layer made of plastic. This document deals more specifically with the field of building construction, and not with vehicle door leaves like the present invention. Furthermore, the preferred embodiment consists of a succession of continuous layers. Consequently, the teaching of this document is not applicable to a transport vehicle door leaf. Indeed, according to the legislation, such a leaf must necessarily be provided with a window, as part of a security-type obligation. This window thus allows passengers to benefit from a visual view of the outside, in order to identify the presence or absence of a platform.

[0011] It should also be noted that, more generally, the person skilled in the art is not encouraged to take this document DE 699 36 046 into account, given that its teaching goes against certain essential objectives of a passenger transport vehicle door. DE 699 36 046 thus describes, among other things, very thick concrete walls. On the contrary, the leaf of a vehicle door must be as thin as possible in order to provide as much space as possible for passengers, while encroaching as little as possible on the external clearance. Furthermore, DE 699 36 046 discloses examples of fixed buildings, the construction of which is not compatible with a leaf which is on the one hand mobile relative to the door frame, the latter being on the other hand in motion relative to the terrestrial reference frame.

[0012] Although the leaf which is the subject of this French patent 3,072,333 provides significant advantages over the state of the art, the applicant wishes to further improve the performance of this leaf.

[0013] Under these conditions, a first objective of the present invention is to propose a leaf with very high acoustic performance, in particular superior to that provided by the solution described in French patent 3,072,333.

[0014] Another objective of the invention is to provide such a leaf having satisfactory rigidity.

[0015] Another objective of the invention is to provide such a leaf, the cost price of which is reasonable and the construction of which can be implemented conveniently. Objects of the invention

[0016] According to the invention, at least one of the above objectives is achieved by means of a door leaf (1; 101) for a passenger transport vehicle, according to the appended claim 1.

[0017] Other advantageous characteristics of the leaf according to the invention are the subject of claims 2 to 12 attached.

[0018] The invention also relates to a door for a transport vehicle, in particular of the train, tram, metro or even trolleybus or bus type, comprising a frame secured to the frame of said vehicle, as well as at least one leaf (1; 101) as defined above, mounted to move relative to said frame.

[0019] The invention finally relates to a transport vehicle, in particular of the train, tram, metro or even trolleybus or bus type, comprising at least one door as defined above. Description of figures

[0020] The invention will be described below, with reference to the appended drawings, given solely as non-limiting examples, in which: [ Fig. 1 ] is a perspective view, illustrating a leaf for a vehicle door according to a first embodiment of the invention, the interior facing of this leaf not appearing in this view. Fig. 2 ] is a perspective view illustrating more particularly a rigid filling plate, belonging to the leaf of the figure 1 . [ Fig. 3 ] is a perspective view, illustrating more particularly different acoustic paving stones equipping the leaf of the figure 1 . [ Fig. 4 ] is a sectional view, along line IV-IV of the figure 1 . [ Fig. 5 ] is a front view, on a larger scale, illustrating detail V of the figure 1 . [ Fig. 6 ] is a front view, on a larger scale, illustrating detail VI of the figure 1 . [ Fig. 7] is a sectional view, similar to the figure 4 , illustrating a variant of the leaf conforming to the first embodiment of the invention. Fig. 8 ] is a front view, partially illustrating a leaf according to a second embodiment of the invention. Fig. 9 ] is a perspective view, illustrating in an exploded manner the different constituent elements illustrated on the figure 8 . [ Fig. 10 ] is a sectional view, along line XX of the figure 8 . [ Fig. 11 ] is a perspective view, on a larger scale, illustrating detail XI of the figure 9 . [ Fig. 12 ] is a sectional view, analogous to the figure 10 , illustrating a variant of the leaf conforming to the second embodiment of the invention.

[0021] The following reference numerals are used in this description: 1 Leaf 10.12 Facings 11, 13 openings of 10,12 14 Glass 20 Filling 25 Separation strips 30 Rigid Fill Region E30 Thickness of 30 31,32 Front faces of 30 34 Cut of 30 36 Recesses 38, 39 Notches of 30 35 plots of 30 40 Paving Stones 40lnf,40Lat groups of paving stones 41, 42 Front faces of 40 43, 44 Upper / lower faces of 40 45, 46 Rear / Front faces of 40 47 High density layer 48 Hollows 50 Intermediate space 50Inf,50Lat space groups 50 52-56 Intervals 40-50 55 Interstitial zone d52-d56 Distance of 52-56 90.92 Sleepers 94.96 Amounts Fig 7 = same ref with “'” P30 median plane 30a, 30b half-plates 42', 43' Ribs Fig 8 to 11 = same ref + 100 154,164 cuts in 130,140 170, 180 Lattice 150 intercalary spaces 150Inf,150Lat space groups 150 160 intercalary spaces 160Inf,160Lat space groups 160 172, 174 Strips of 170 182, 184 Strips of 180 176, 186 Junctions between bands Cx Center of x (150, 160, 176, 186) 177, 187 Partial recesses 178, 188 Projections 152 Paving ( fig 12 ) 158 Interstitial zone Detailed description

[0022] The attached figures illustrate a leaf according to a first embodiment of the invention, which is designated as a whole by the reference 1. This leaf forms the opening of a door, equipping a transport vehicle. This door also comprises a frame of conventional type, not shown in the figures, which is arranged at the periphery of an opening made in the body of this vehicle. This door can be provided with a single leaf according to the invention, or with at least two such leaves.

[0023] In the various figures, the actual proportions of the various constituent parts are not necessarily represented to scale, for the sake of clarity of the drawings. Furthermore, these proportions may vary from one figure to another, in order to better emphasize the various characteristics of the invention.

[0024] In the example illustrated, the leaf 1 equips a transport vehicle, of the suburban train type. The invention, however, finds its application to leaves intended to equip other transport vehicles such as in particular trams, trolleybuses, buses, metros, or even trains other than that mentioned above. In the following, it is assumed that the leaf 1 is vertical, in particular with reference to the figure 1 Furthermore, the terms “interior” and “exterior” are used in reference to the body of the transport vehicle equipped with this leaf.

[0025] Leaf 1 essentially comprises: an interior facing 10; an exterior facing 12; a filling 20 occupying part of the interior volume, delimited by the two facings 10 and 12. This filling, which constitutes an essential element of the invention, will be detailed in more detail in the following. peripheral mechanical elements 90 to 96, ensuring in particular structural and sealing functions.

[0026] Each facing 10 or 12, of a type known per se, is made of any suitable material. It is typically formed by a metal sheet, preferably made of aluminum alloy, stainless steel or composite material, in which a respective opening 11 or 13 is provided for the installation of a window 14 (see figure 1). These facings 10 and 12 have substantially identical dimensions. By way of non-limiting example, their height is between 1,900 and 2,500 millimeters, their width is between 600 and 1,200 millimeters, while their thickness is between 25 and 60 millimeters.

[0027] As shown in particular in figure 2, the filling 20 firstly comprises a first region 30, called rigid filling, which is formed by a plate produced for example by machining or molding. For the purposes of the invention, the term rigid means that the Young's modulus of the plate 30 has a relatively high value, which allows it to withstand the usual stresses undergone by the leaf. Advantageously, this Young's modulus is greater than 50 MPa (megapascals), in particular 60 MPa, typically being between 80 and 120 MPa. In the example illustrated, this plate is a single-piece, i.e. formed from a single piece. However, as a variant not shown, it is possible to use several plates of smaller frontal dimensions, arranged next to each other.

[0028] The rigid filling plate 30 is made of a first material, which has relatively high rigidity characteristics, but on the other hand relatively low acoustic properties. This first material, of a conventional type, is, among others, a polyurethane foam (PU), a polyethylene terephthalate foam (PET) or any other suitable material, of a conventional type. For example, the typical density of this first material is close to 100 kg per cubic meter.

[0029] This plate 30 has a maximum thickness, noted E30 ( figure 4), which corresponds substantially to the spacing between the two facings 10 and 12. For example, this thickness is therefore between 20 and 60 millimeters. 31 and 32 denote the two front faces of this plate, respectively interior and exterior, which are fixed against the respective facings 10 and 12. Preferably, this fixing is of the permanent type, in particular by gluing.

[0030] The plate 30 is first hollowed out with a cutout 34, which is said to be through insofar as it opens onto the opposite front faces 31 and 32. This cutout allows clearance for the aforementioned window 14. Furthermore, this plate 30 has several recesses 36, forming receiving housings for second regions 40 belonging to the filling 20, which will be detailed below. These housings are blind, insofar as they open only onto the inner front face 31 of the plate 30. Finally, this plate is hollowed out by means of lateral notches 38 and 39, which allow the insertion of conventional components not shown, such as handles or locks of types known per se.

[0031] In this first embodiment, each second region, which is said to be acoustically insulating, is formed by a parallelepiped-shaped block. In the illustrated example, there are first of all two lines of blocks 40a to 40d, as well as 40e to 40h, which are located below the window 14. These two lines form a first group of blocks, also called the lower group 40lnf, as referenced on the figure 3 . There is also a row of additional blocks 40i to 40l, which extend along the side of the aforementioned window. This row forms a second group of blocks, also called the lateral group 40Lat, as referenced on the same figure 3 . On the figure 2 , we note 36a to 36l the different recesses, which are intended to receive the paving stones described above.

[0032] In the embodiment illustrated in particular on the figure 1, the blocks 40a, 40c, 40d, 40e as well as 40g and 40h are substantially identical. In this spirit, it can be considered that the dimension of these different blocks constitutes a so-called standardized size, it being understood that it is preferable to manufacture as few different block sizes as possible, for reasons of simplicity. Nevertheless, the size and shape of certain blocks can be adapted locally to the presence of certain components, such as push buttons, locks or even handles. Thus, in the present embodiment, the blocks 40b and 40f have a width slightly greater than that of the blocks above. Furthermore, the blocks 40i to 40k are substantially identical, while the block 40l has a slightly smaller width due to the presence of a component such as a handle.

[0033] As is clear from the above, the number, size and arrangement of the different paving stones are given for information purposes only. In other words, these different parameters, characteristics of the paving stones 40, are likely to vary from one leaf to another without, however, departing from the scope of the invention.

[0034] The above blocks are made of a second material, in particular an open-cell foam having a low density, a glass wool, or a mineral wool having absorption characteristics. This material can be of the woven or non-woven type. This second material, which is called an acoustic material within the meaning of the invention, is different from the first material constituting the plate 30 in that it has sound insulation properties that are significantly superior to those of the first material. To this end, this second material has a flexibility that is significantly greater than that of the first material, namely that the Young's modulus of this second material is significantly lower than that of the first material. Advantageously, the so-called apparent Young's modulus of this second material is typically less than 50 kPa (kilopascals), in particular less than 10 kPa.

[0035] According to the invention, the various housings have dimensions greater than those of the paving stones received therein. With reference to the figures 4 to 6 , we call the six peripheral faces of a block 40. We thus note 41 and 42 the opposite frontal faces, as well as 43 and 44 the lateral faces respectively upper and lower ( figure 4 ). On the Figures 5 and 6 we note 45 and 46 the rear and front lateral faces respectively of block 40, in reference to the direction of travel of the vehicle.

[0036] Each paving stone is fixed, on the inner facing, at its first front face 41. Advantageously, a layer 47 of a high-density material is interposed between this front face and this inner facing. This layer 47 is typically formed by a bituminous product or even of a viscoelastic nature, having damping characteristics. In the example illustrated, there are two layers of adhesive not shown, one of which allows the paving stone to be fixed on the layer 47, and the other of which allows this layer 47 to be fixed on the inner facing.

[0037] With particular reference to figures 4 to 6, the faces 42 to 46 of the block 40 delimit, with the facing walls of the plate 30, an intermediate space designated as a whole by the reference 50. This space 50 is formed by different intervals 52 to 56, extending between the plate and the aforementioned faces 42 to 46. It will be noted that the block 40 is in contact, by only one of its faces, with the interior facing. On the other hand, its five other faces are distant from the plate 30 which, as will be seen in the following, is particularly advantageous from an acoustic point of view.

[0038] Since each interspace surrounds a respective paving stone, there are two groups of interspaces corresponding to the groups of paving stones as illustrated in figure 3 . We thus note, in a manner analogous to what was described above, a lower group 50Inf of intercalary spaces, formed by the intercalary spaces 50a to 50h of the figure 1. Furthermore, the lateral group 50Lat is formed by the intercalary spaces 50i to 50l of the figure 1 . It will be noted that, on this figure 1 , we have not referenced all of these intercalary spaces, in order not to overload the drawing. Adjacent intercalary spaces are mutually separated by a strip, made of rigid material. On the figure 4 , one of these bands has been shown, which separates the block 40b and its intercalary space 50b, relative to the block 40f and its intercalary space 50f.

[0039] The dimension of each interval is denoted d52 to d56, namely the smallest distance separating the plate from a respective face 42 to 46. A person skilled in the art will choose each dimension so that, during any deformations undergone by the paving stone in service, the aforementioned faces do not come into contact with the plate. In this spirit, each of the above dimensions, which define what is called the “thickness” of the intermediate space 50, is typically between 3 mm and 8 mm. In particular, these different dimensions d52 to d56 are substantially equal to each other.

[0040] Furthermore, as shown in particular by the figure 4, the plate 30 is advantageously provided with different studs 35a to 35l, which project from the bottom of each housing towards the interior facing. Under these conditions, each stud extends through a central recess 48a to 48l, provided in a respective paving stone. In service, these studs provide a reinforcing function, in particular by opposing any possible subsidence of the paving stones. It will be noted that the studs are not in contact with the paving stones, through which they extend. Thus, with reference to the figure 4 , the peripheral faces of each pad 35 delimit, with the walls of the corresponding recess 48, an interstitial zone 58. The dimensions of the latter are close to those of the intermediate space 50, as described above, in order to avoid any contact in service between the facing faces of the pad and the paving stone.

[0041] It is understood that, due to the presence of the interlayer space 50, the filling delimited between the facings is not entirely occupied by a solid material. Thus, this interlayer space is filled by means of a gas. In the absence of additional operations, this gas is naturally formed by the ambient air. However, as a variant, it is possible to inject another type of gas into the interlayer space.

[0042] A frame, formed by two crosspieces 90 and 92 and two uprights 94 and 96, is fixed on the facings 10 and 12, on the periphery of the plate 30 (see in particular the figure 1). This fixing is ensured in a conventional manner, in particular by gluing. These crosspieces and uprights are first hollowed out with respective grooves, allowing the reception of sealing joints not shown. Furthermore, these crosspieces and uprights carry additional elements, also not shown, ensuring mechanical connections with the vehicle frame. The various mechanical means, to which reference is made in this paragraph, are of the conventional type so that they are not described in more detail in what follows.

[0043] It should be noted that the invention is particularly aimed at vehicles equipped with air-tightness means, in particular as described in the preceding paragraph for the door. Indeed, in the absence of such means, the sound insulation of the vehicle is very seriously penalized.

[0044] The dimensioning of the leaf 1 above, in particular of the plate 30 and its recesses 36, as well as the paving stones 40, is similar to that described in French patent 3,072,333 discussed above. In general, those skilled in the art will ensure that satisfactory acoustic attenuation is obtained, while preserving the overall mechanical strength of the leaf. In particular, those skilled in the art will advantageously choose a range between 0.25 and 0.7, in particular between 0.4 and 0.6, for the ratio between the total frontal surface of the paving stones 40 and the frontal surface of the plate 30 (not taking into account the surface of the cutout 34). The positioning of the various paving stones will also take into account the constraints due to the actual geometry of the leaf.

[0045] There figure 7 illustrates a variant of the first embodiment, described above. In this figure 7 mechanical elements similar to those of figures 1 to 6are assigned the same reference numbers, to which the sign “'” is added.

[0046] Depending on the variant of the figure 7 , the acoustic paving stones 40 are not placed in contact with the interior facing. On the contrary, these paving stones 40' are distant from the interior facing, that is to say that they are provided in a so-called "middle" position, substantially in the middle of the facings 10 and 12. As in the main variant, these paving stones 40' are separated from the walls of their receiving housings, by an intermediate space 50'.

[0047] From a construction point of view, it is possible to provide for the plate 30' to be made in the form of two half-plates 30a and 30b, symmetrical with respect to the median vertical plane P30 of this plate. These half-plates are then fixed with respect to each other, in particular by gluing. In order to ensure the stability of each paving stone 40', it is provided that the plate 30' is provided with means for holding this paving stone in place. In the example illustrated, these holding means are made in the form of ribs 42' and 43', bearing against the upper and lower faces respectively of the paving stone.

[0048] THE figures 8 to 11 illustrate a leaf 101, which is in accordance with a second embodiment of the invention. In these figures 8 to 11 mechanical elements, similar to those illustrated on the figures 1 to 6 , are assigned the same reference numbers increased by the number 100. The figure 8illustrates, in part, the lower part of this leaf, namely the one located below the glass of this leaf. For this purpose, broken lines have been illustrated at the top of this figure 8 . On the other hand, the exploded perspective of the figure 9 illustrates, in part, the part of the leaf extending immediately above this window. Broken lines have also been illustrated at the top of this figure 9 .

[0049] This second embodiment differs from the first embodiment above, in particular with regard to the nature and structure of the second region 140 of the filling 120. Thus, this second region 140 is not made of a material whose acoustic insulation properties are superior to those of the material constituting the first region 130. In the example illustrated, these regions are substantially identical, namely that they are made in the form of two adjacent plates 130 and 140, symmetrical with respect to the median vertical plane P120 of the filling 120. Consequently, the thickness of each half-plate is equal to half that E30 of the plate of the first embodiment. As this is partially shown in the figure 9, the plates 130 and 140 are typically each hollowed out with a cutout 154 and 164 similar to that 34 of the plate 30. On the other hand, in order not to overload the drawing, the lateral notches, similar to those 36 of the plate 30, have not been shown.

[0050] Each plate 130, 140 comprises a respective lattice 170, 180, which is formed by a plurality of strips of material, respectively horizontal 172, 182 and vertical 174, 184. The strips of material, belonging to the same lattice, intersect at a multiplicity of junctions 176, 186. These strips are perforated by notches, which form intermediate spaces 150 and 160 within the meaning of the invention. In the example illustrated, each notch is said to be through, that is to say that it extends on either side of the lattice.

[0051] As in the first mode of regulation, there is a plurality of both intermediate spaces 150 and intermediate spaces 160. As shown more particularly in figure 9 , the intermediate spaces 150 are divided into a lower group 150Inf and a lateral group 150Lat. Furthermore, the intermediate spaces 160 are divided into a lower group 160lnf and a lateral group 160Lat. The distribution of these different groups of intermediate spaces is similar to that described above, with reference to the groups of paving stones 40lnf and 40Lat of the figure 3 . Each lateral group 150Lat and 160Lat is illustrated partially, it being understood that it has the same structure as the respective lower group 150Inf and 160Inf. Furthermore, each of these lateral groups is hatched for clarity, in order to better distinguish it from the adjacent structural elements.

[0052] In front view, as shown in the figure 8, these lattices 170,180 and, consequently, the intercalary spaces, are offset from each other. Let C150 and C160 denote the center of the notches, as well as C176 and C186 the center of the junctions. Each center C150 of a notch, belonging to the first plate 130, is merged with each center C186 of a junction, belonging to the other plate 140 while, in a conjugate manner, each center C160 is merged with each center C176. With reference to the figure 10 , seen from the side, each notch 150 communicates with an adjacent notch 160.

[0053] Furthermore, the different bands have partial recesses 177,187, which delimit projections 178,188. The figure 11illustrates, on a larger scale, certain recesses 187 and certain projections 188, it being understood that the recesses 177 and the projections 178 are analogous to them. These projections 178 and 188 form contact zones allowing fixing, in particular by gluing, between the plates 130 and 140. In front view, each projection is located at the level of a respective strip, substantially in the middle of two adjacent junctions.

[0054] In reference to the figure 8 , we note sfthe frontal surface of each contact and fixing zone, which corresponds substantially to the frontal contact surface between the adjacent projections 178, 188. Furthermore, SF denotes the sum of all the frontal surfaces sf. In the region formed by the lattices 170 and 180, the plates 130 and 140 are in contact only at their different fixing zones. Consequently, SF is also called the overall frontal contact surface between said plates. As shown in this figure 8 , this overall contact area is significantly less than the S170 area of ​​each lattice. Advantageously, on an industrial prototype, the SF / S170 ratio was less than 17%. In other words, in this example, more than 83% of the solid contact areas between adjacent lattices 170 and 180 were removed.

[0055] In this second embodiment, it is possible to provide lattices, similar to those described above, on one or even two lateral parts of the window of the leaf. Generally speaking, in either embodiment, it is advantageous to provide as many areas as possible whose acoustics are improved thanks to the presence of the interposed spaces. The total surface area of ​​these areas will be limited, on the one hand, by a concern for the overall mechanical strength of the leaf and, on the other hand, by taking into account the predefined location of the various usual elements of the leaf.

[0056] There figure 12illustrates a variant of the second embodiment, described above. According to this variant, at least one intercalary space 150 receives a paving stone 152, made of a material similar to that constituting a paving stone 40 of the first embodiment. This paving stone 152 is fixed by one of its faces on the facing facing, here that 112, while its other faces are separated from the facing faces, belonging to the respective plates 130 and 140. 158 denotes the interstitial zone thus formed, the dimensions of which are typically close to the intercalary space 50; or else to the interstitial zone 58 of the first embodiment. Provision may also be made, in a manner not shown, to fix at least one additional auxiliary paving stone on the other facing 110.

[0057] As a variation, not shown on this figure 12, it is first possible to provide that a layer of a high-density material, similar to that 47 of the first embodiment, is interposed between the auxiliary block 152 and the facing 112. As an additional variant, also not shown, it is possible to provide that the rigid filling region 140 is equipped with a reinforcing pad, similar to that 35 of the first embodiment, which extends through the auxiliary block. As in this first embodiment, the facing faces of the pad and the auxiliary block 152 are then separated by an interstitial zone, similar to that 58 described above.

[0058] The invention makes it possible to improve the acoustic insulation properties of the leaf, in accordance with the teaching of French patent 3,072,333 above. It will be recalled that, in this patent, acoustic paving stones are provided, received in respective housings, the dimensions of which are similar to those of the paving stones. It is even specified that, advantageously, the housing can be slightly smaller to promote slight compression of the paving stone.

[0059] Under these conditions, considering the leaf in side view, the entire filling present between the opposite facings is formed solely by a succession of layers of solid materials. However, the applicant has found that this continuous “entirely solid” filling does not, at least under certain conditions, ensure optimal sound attenuation. Despite the use of specific materials, this continuous filling does not contribute to resolving the problem of solid vibration transmission bridges between the opposite facings, which are encountered in the usual leaves of the state of the art.

[0060] On the contrary, the present invention provides for integrating, in a part of this filling, at least one intermediate space free of any solid material. Such an intermediate space, occupied by a gas such as air, makes it possible to improve the overall acoustic insulation of the leaf without significantly altering its overall mechanical strength. In particular, the presence of the intermediate spaces makes it possible to break, to a significant extent, the vibrational solid transmission bridges presented above. Under these conditions, the leaf 1 or 101 according to the invention has significantly superior acoustic insulation properties to that of a so-called control leaf, namely a similar leaf which would not integrate such intermediate spaces.In practice, the person skilled in the art, wishing to follow the teaching of the present invention, will remove as many solid transmission bridges as possible, while ensuring that the final leaf still has the necessary mechanical strength characteristics.

[0061] In more detail, the leaf 1 in accordance with the first embodiment of the invention includes intermediate spaces 50 allowing sound insulation properties much superior to those of a control leaf, which would be generally in accordance with the teaching of French patent 3,072,333. In substance, in this first embodiment, the paving stone has dimensions smaller than those of its housing, so as to delimit an intermediate space. Under these conditions, there is advantageously no contact between the paving stone and the walls of the housing, at least in the absence of constraints. Consequently, the applicant has noted that this play, deliberately provided between the paving stone and its housing, gives freedom to the material constituting this paving stone during vibrations and acoustic resonances. This contributes, to a significant extent, to improving the sound insulation performance of this leaf.

[0062] Furthermore, the leaf 101 according to the second embodiment includes intermediate spaces 150 and 160, which allow sound insulation properties much superior to those of a control leaf, the filling of which would be formed by two continuous plates attached to each other. The applicant has in particular noted that the presence of the lattices gives very high sound insulation performance to the leaf equipped with them, at least on certain frequency bands. Furthermore, thanks to the presence of the lattices, the leaf according to this second embodiment has a very satisfactory lightness.

[0063] The provision of a plurality of interposed spaces, both in the first and in the second embodiment, makes it possible to adapt as best as possible to the necessary presence of the glass. This adaptation is all the more satisfactory by providing, according to a particularly advantageous characteristic of the invention, a lower group combined with a lateral group of interposed spaces.

Claims

1. Door leaf (1; 101) for a passenger transport vehicle, in particular for a tram, trolleybus, bus, metro or train door, comprising: - a so-called interior facing (10; 110) intended to be placed on the interior side of the vehicle body and a so-called exterior facing (12; 112) intended to be placed on the exterior side of the vehicle body, said facings delimiting an interior volume of said leaf, each facing being hollowed out with an opening (11, 13, 111, 113) for receiving a window (14; 114) - a filling (20; 120) occupying this interior volume, this filling being hollowed out with at least one cutout (34; 134, 144) for receiving said window (14) - a structural frame (90, 92, 94, 96) extending to the periphery of the core of the leaf, - mounting means, allowing the mounting of the leaf on the frame of said door, characterized in that the filling comprises - at least one first region (30; 130), called rigid filling, made of a first material, called rigid filling material, having a Young's modulus greater than 50 MPa, in particular greater than 60 MPa, this first region covering at least part of a first facing, in particular of the external facing - at least one second region (40; 140), made of a second material - a plurality of interspaces (50; 150, 160) which are separated from each other by separation strips (25; 172, 174, 182, 184), made of said first material, each interspace being occupied by a gas, in particular air, each interspace being capable of breaking at least a part, advantageously at least a substantial part, of the solid vibratory transmission paths between the facings.

2. Leaf according to claim 1, characterized in that the interspaces comprise a first group, called lower, of interspaces (50Inf; 150Inf; 1601nf) extending below a respective cutout (34; 134, 144), as well as a second group, called lateral, of interspaces (50Lat; 150Lat; 160Lat) extending on the side of a respective cutout.

3. Leaf (1) according to one of the preceding claims, characterized in that the second material has acoustic insulation properties significantly superior to those of the first material, said second material having in particular a Young's modulus significantly lower than the Young's modulus of said first material, so that each second region (40) forms an acoustic insulating region, intended to oppose the vibrational solid transmission, each acoustic insulating region being for example constituted by a block (40), in particular of parallelepiped shape.

4. Leaf according to the preceding claim, in which each intermediate space (50) is provided between the facing faces of the rigid filling region (30) and a respective acoustic insulating region (40), a front face (41) of the acoustic insulating region (40) being in particular fixed against the interior facing (10), while the other faces of this acoustic insulating region are in particular distant from the walls of the first rigid filling region (30).

5. Leaf according to one of claims 3 to 4, in which the first rigid filling region (30) comprises at least one reinforcement stud (35), this stud projecting through the acoustic insulating region (40) towards the facing, in particular the interior facing, the facing faces of the stud and of the insulating region being in particular separated by an interstitial zone (58).

6. Leaf according to one of claims 3 to 5, in which, in side view, each acoustic insulating region (40') is placed in a substantially median position, at a distance from each facing (10, 12), the first solid filling region (30) advantageously having mechanical means for holding each acoustic block placed in the median position, in particular ribs (42, 43) which are capable of blocking the respectively upper and lower faces of each acoustic insulating region.

7. Leaf according to one of claims 3 to 6, wherein a plurality of second regions are provided, advantageously a lower group (40Inf) of second regions extending below said cutout (34), as well as a lateral group (40Lat) of second regions extending on the side of said cutout.

8. Leaf (101) according to one of claims 1 to 2, in which the second material has acoustic insulation properties close to those of the first material, the first and second materials being in particular merged, so that the second region forms a second rigid filling region (140) covering at least part of the other facing, in particular the interior facing (110).

9. Leaf according to the preceding claim, in which each interspace (150, 160) is provided in the volume of a respective rigid filling region (130, 140).

10. Leaf according to one of claims 9, in which, in front view, the interspaces (150) of the first filling region (130) are offset relative to the intermediate spaces (160) of the second filling region.

11. Leaf according to one of claims 8 to 10, in which each rigid filling region (130, 140) is produced in the form of a lattice, this lattice comprising said separation strips (172, 174, 182, 184) perforated by notches, said notches forming said plurality of interspaces (150, 160).

12. Leaf according to one of claims 8 to 11, in which at least one interspace (150) is partly occupied by an auxiliary block (152), made of an acoustic insulation material, this auxiliary block preferably being fixed on a facing without being in contact with the rigid filling regions.

13. Door for a passenger transport vehicle, in particular of the train, tram, metro or trolleybus or bus type, comprising a frame secured to the frame of said vehicle, as well as at least one leaf (1; 101) in accordance with any one of the preceding claims, mounted to move relative to said frame.

14. Passenger transport vehicle, in particular of the train, tramway, metro, trolleybus or bus type, comprising at least one door as claimed in the preceding claim.