Acoustic barrier, particularly for railway superstructures

Abstract: The acoustic barrier, particularly for railways, comprises at least a first sound-proofing member (2), arranged at the sides of a train (3) proximate to at least each bogie (4), and at least a second sound-proofing member (5) arranged on the supporting plane (6) of the rails (8) at the sides of said rails, the second sound-proofing member cooperates with the first sound-proofing member for abating the noise generated by the passage of the train on the rails.

Description: The present invention relates to an acoustic barrier, particularly for railway superstructures. As known, the acoustic pollution has now reached a paramount importance in designing, developing, and producing machines and apparatus in all fields, particularly in the construction and industrial fields. There are several possibilities of eliminating the noise without reducing the productivity: it is for example possible to intervene in the arrangement of the machines, to modify the noise generating parts, to provide shields or active systems, improve the sound proofing of the buildings, install sound-proofing or noise-reducing barriers. In railways, for example, this problem has been particularly felt because railways passing close or in the cities are a great source of acoustic pollution. So far, the problem of the acoustic pollution of the railways has been partially solved by arranging sound-proofing barriers at the sides of the ballast or, in the case of railways on tie plates, at the sides of the tie plates. Conventional acoustic barriers however limit only a fraction of the noise produced by the passage of trains. In the Technical Disclosure Bulletin n.78 by the British Railways Board is disclosed an acoustic barrier for railways having the features disclosed in the pre-characterizing part of claim 1 while in JP-A-51 143 205 is disclosed are inclined slot with respect to the supporting plane. The above documents do not disclose a barrier having features as disclosed in the characterizing part of claim 1. The aim of the present invention is to eliminate the above described shortcomings of conventional acoustic barriers, particularly for railways. Within this aim, an important object of the invention is to provide an acoustic barrier, particularly for railways, adapted to almost completely abate the noise produced by the passage of a train. A further object of the invention is to provide an acoustic barrier, particularly for railways, adapted to abate the noise and to improve the aerodynamics of the train. A further object of the invention is to provide an acoustic barrier, particularly for railways, adapted to abate the noise and to mechanically protect the moving members (the train wheels). Still a further object of the invention is to provide an acoustic barrier which also has an intrinsic safety in that it prevents objects from being dragged under or close to the wheels of the passing train. The above aim and objects are achieved by an acoustic barrier, particularly for railways as disclosed in claim 1. Further characteristics and advantages of the invention will be more apparent by the description of a preferred but not exclusive embodiment of the acoustic barrier, particularly for railways, illustrated, by way of indicative but not exclusive example in the enclosed drawings wherein: FIG. 1 is a prospective view of a train bogie showing its case and barrier according to the general background of the present invention. FIG. 2 shows a variated embodiment of the case and the second sound-proofing member according to the invention; FIG. 3 is a schematic perspective view of a train having the case mounted on the bogie, according to the invention. With reference to the above figures, the acoustic barrier, particularly for railways, according to the invention, generally designated by the reference numeral 1, comprises at least a first sound-proofing member 2 arranged at the sides of a train 3, proximate to at least each bogie 4. The barrier also comprises at least a second sound-proofing member 5 arranged on a support plane 6 of rails 8. In particular, second sound-proofing member 5 is arranged as close as possible to rails 8 in order to cooperate with first sound-proofing member 2 thus practically completely abating the noise generated by the passage of train 3 on rails 8. First sound-proofing member 2 is defined by a case 9 covering wheels 10 of the train bogie 4. Case 9 conveniently extends proximate to rails 8 in order to cover wheels 10 completely and to perform a first abating of the noise generated by the wheels turning or sliding on rails 8. Advantageously, case 9 is associated with bogie 4 so that it is not influenced by the swinging and movements of the train frame due to the shock absorbers provided for the passengers comfort. Furthermore, as known, some fast trains lean into the curves and therefore should the case be associated to the car frame it would hit the support plane 6 of rails 8. In a preferred embodiment of the invention, case 9 is associated with bogie 4 with shock absorber members, such as springs or plastics cushions, and has a portion 11 between bogie 4 and the frame of train 3, adapted to improve the acoustic insulation of the passenger cabin of the train. In other words, in this embodiment, the case is provided to completely cover bogie 4 in order to acoustically insulate it. Second sound-proofing member 5 is instead defined by a noise reducing and abating barrier 12. Barrier 12 is arranged parallel to rails 8 and is substantially higher than the rails. As shown in FIG. 2, at least barrier 12 has a portion 50 of sound-proofing material extending towards case 9, while case 9 has a portion 51 extending towards portion 50 of barrier 12. In this manner, as shown in FIG. 2, barrier 12 and case 9 have a complementary shape adapted to create a labyrinth that converges the noise produced by bogie 4, towards barrier 12 which almost completely abates it. It is also noted that barrier 12 has a first channel inside its body. First channel is adapted to stiffen the barrier and to abate noise, and is also adapted to accommodate electric cables which are thereby protected by the environment and by tampering or damages along the line. In a preferred embodiment of the invention, barrier 12 has a second stiffening channel on its upper end. Electrical and telephone cables may be inserted in said second channel for protection against the environment and damages. It is specified that said second channel and the portion of case 9 facing said second channel are provided with layers of sound-proofing material. Barrier 12 also has one or more flexible fins adapted to merge its base 23 with support plane 6 of rails 8 should the support plane be inclined such as a ballast. It is also noted that either the case or the barrier, or both, have anti-friction members on their facing sides, should case 9 hit barrier 12 in case of swervings of the train or other unexpected reasons. If necessary, case 9 may also have one or more fins adapted to force an air flow towards the braking system of bogie 4 for cooling the brakes. Furthermore, both case 9 and barrier 12 are provided with stiffening ridges, not shown in the drawings, and may be provided with electronic systems for example for detecting the exact position of the train on the railway, for measuring the exact speed of the train, or for activating one or more safety systems or level crossings or signals at the stations. Advantageously, case 9 may be made of alveolar fiberglass having a high mechanical and chemical resistance, because of the considerable stress to which the case is subjected and because of the chemical attacks of several materials such as oils, salt, etc., normally present in a railway bogie. The use of the acoustic barrier according to the invention is apparent from what has been described and illustrated. In particular, the combination of barrier 12 and case 9, together with their particular shape, provide a unique protective barrier against the noise generated by the train passage, which is adapted to abate the noise almost completely since the sound waves have no possibility of propagation. It has been seen in practice that the acoustic barrier according to the invention is particularly advantageous because it almost completely abates the noise generated by the passage of the train and, at the same time, improves the train aerodynamics. The acoustic barrier also effectively mechanically protects the bogie members also preventing objects from being dragged under or close to the wheels, as frequently happens in conventional trains, also preventing people or animals from being drawn under the wheels. The acoustic barrier according to the invention may have numerous modifications and variations, all within the inventive concept as defined in the claims. Furthermore, all the details may be substituted with technically equivalent elements. The materials employed, as well as the dimensions, may be any according to the specific needs and the state of the art. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.

Claims: Acoustic barrier system, particularly for railways, comprising at least a first sound-proofing member (2) arranged at the sides of a train (3) proximate to at least each bogie (4), and at least a second sound-proofing member (5) arranged on the supporting plane (6) of the rails (8) at the sides of said rails, said second sound-proofing member cooperating with said first sound-proofing member for abating the noise generated by the passage of said train on said rails, wherein said first sound-proofing member has a case (9) which covers the wheels (10) of said bogie (4) and is associated with each bogie (4) of said train, said case being independent of the frame of said train and having lower ends below the axes of said wheels and wherein said second sound-proofing member (5) comprises a noise reducing and abating barrier (12) arranged parallel to said rails and extending upwardly above said lower ends to overlap said case (9), characterized in that said barrier has an inclined lower portion (50) extending from said supporting plane toward said bogie (4) and projecting past the horizontal plane corresponding to the zone of contact between said wheels and said rails and an inclined upper portion extending, from the end of said lower portion, with opposite inclination with respect to said lower portion in order to define with said lower portion a knee higher than said contact zone and pointing toward said bogie, lower portions of said case and said upper portion of said barrier (12) being inclined to said support plane (6) to define between each lower portion of the case and a respective upper portion of the barrier juxtaposed therewith a respective slot inclined to said support plane. Barrier system according to claim 1, characterized in that said case (9) is shock absorbingly associated with the bogie of said train and has at least a portion (11) arranged between said frame and said bogie for acoustically insulate the passenger cabin of said train. Barrier system according to one or more of the preceding claims, characterized in that said barrier has a first stiffening channel inside its body, adapted to accommodate electrical cables. Barrier system according to one or more of the preceding claims, characterized in that said barrier has a second stiffening channel, at an upper end, adapted to accommodate electrical cables. Barrier system according to one or more of the preceding claims, characterized in that said barrier (12) has one or more flexible fins adapted to merge its base with said supporting plane (6). Barrier system according to one or more of the preceding claims, characterized in that at least said barrier (12) or at least said case (9) have anti-friction members at their facing surfaces. Barrier system according to one or more of the preceding claims, characterized in that said case (9) has at least one finning for forced cooling the braking system of said bogie. Barrier system according to one or more of the preceding claims, characterized in that said barrier and said case have stiffening ridges. Barrier system according to one or more of the preceding claims, characterized in that said case and said barrier have electronic detecting devices. Barrier system according to one or more of the preceding claims, characterized in that said case is made of alveolar fiberglass.

Inventors: UGHI STEFANO, UGHI, STEFANO
Applicants: UGHI STEFANO, UGHI, STEFANO
Application year: 1996
Main classification: E01B19
IPC codes: E01B19, B61D49