TYRE COMPRISING A NOISE-REDUCING ELEMENT

Abstract

The present disclosure is directed to a tyre comprising a tread band having one or more reliefs with circumferential development, and a noise-reducing element applied on an inner surface of the tyre and extending along at least half of a circumferential development of the inner surface, wherein the noise-reducing element comprises a series of radially through openings, wherein the series of openings extends along the circumferential development of the inner surface and wherein the series of openings is placed so that at least half of an overall plant area of the openings of the series of openings is placed at one relief of the one or more reliefs.

Claims

1-17. (canceled)

18. A tyre comprising a tread band having one or more reliefs with circumferential development, and a noise-reducing element applied on an inner surface of the tyre and extending along at least half a circumferential development of the inner surface, wherein the noise-reducing element comprises a series of radially through openings, wherein the series of openings extends along the circumferential development of the inner surface and wherein the series of openings is placed so that at least half of an overall plant area of the openings of the series of openings is placed at one relief of the one or more reliefs.

19. The tyre according to claim 18, wherein the noise-reducing element comprises one or more further series of radially through openings, wherein each further series of openings extends along the circumferential development of the inner surface and wherein at least one of the one or more further series of openings is placed so that at least half of an overall plant area of the openings of the at least one, or of each, further series of openings is placed at one respective further relief of the one or more reliefs.

20. The tyre according to claim 19, wherein the openings of the series of openings is placed so that at least 60% of the overall plant area of the openings of the series of openings is placed at one relief of the one or more reliefs, or the openings of the at least one, or of each, further series of openings is placed so that at least 60% of the overall plant area of the openings of the at least one, or of each, further series of openings is placed at one respective further relief of the one or more reliefs.

21. The tyre according to claim 19, wherein the noise reducing element extends along substantially the whole circumferential development of the inner surface, wherein the openings of the series of openings, or the openings of each of the one or more further series of openings, are arranged along substantially the whole circumferential development of the inner surface.

22. The tyre according to claim 19, wherein the series of openings comprises openings having a same shape and dimensions, wherein each of the one or more further series of openings comprises openings having the same shape and dimensions, wherein all the further series comprise a same number of openings, and wherein the openings of all the further series of openings have the same shape and dimensions and circumferential arrangement.

23. The tyre according to claim 19, wherein a boundary surface of each opening has a substantially radial development, wherein a section of each opening, perpendicular to an axis of development of the opening, is constant along the axis of development, and wherein the openings of the series of openings, the openings of each of the one or more further series of openings, or the openings of the series of openings and the openings of each of the one or more further series of openings, are substantially axially aligned with each other.

24. The tyre according to claim 19, wherein the noise-reducing element comprises at least two further series of radially through openings.

25. The tyre according to claim 19, wherein each opening of the one or more further series of openings has a section, perpendicular to an axis of development thereof, having an elongated shape with a main dimension, wherein the main dimension of the openings is substantially parallel to the circumferential development.

26. The tyre according to claim 25, wherein the main dimension of each opening has a length greater than or equal to 5 cm and less than or equal to 15 cm, and wherein the elongated shape comprises two end portions along the main dimension having a lobed shape and a central portion, of reduced size, which interconnects the two end portions.

27. The tyre according to claim 18, wherein the noise-reducing element comprises a plurality of noise-reducing sub-elements applied circumferentially in sequence along the circumferential development of the inner surface of the tyre.

28. The tyre according to claim 27, wherein the noise-reducing element, or each noise-reducing sub-element, is a parallelepiped in the non-deformed configuration, wherein the noise-reducing element comprises a sound-absorbing material and wherein the sound-absorbing material has a density ranging from about 5 kg/m.sup.3 to about 60 kg/m.sup.3.

29. The tyre according to claim 18, wherein the openings are arranged onto the noise-reducing element according to an ordered scheme, wherein the ordered scheme comprises a base module repeated along the circumferential development.

30. The tyre according to claim 29, wherein the base module has a first symmetry plane parallel to an equatorial plane of the tyre, and wherein the base module has a second symmetry plane perpendicular to an equatorial plane of the tyre.

31. The tyre according to claim 29, wherein the base module comprises a first set of openings belonging to the series of openings, wherein a number of openings of the first set is greater than or equal to one, and less than or equal to three, wherein the base module comprises a second set of openings for each of one or more further series of openings, and wherein a number of openings of each second set it is greater than or equal to two, and less than or equal to four.

32. The tyre according to claim 29, wherein the noise-reducing element comprises a plurality of noise-reducing sub-elements applied circumferentially in sequence along the circumferential development of the inner surface of the tyre, and wherein each noise-reducing sub-element comprises one base module.

33. The tyre according to claim 18, wherein each opening of the series of openings has a section, perpendicular to an axis of development thereof, of circular shape having a diameter, wherein the diameter is greater than or equal to 2 cm, and less than or equal to 6 cm.

34. The tyre according to claim 18, wherein a ratio between an overall volume of all the openings present on the noise-reducing element, and an overall volume of the noise-reducing element, is greater than or equal to 0.1, and less than or equal to 0.4.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0077] FIG. 1 shows a partial view of a plane development of a crown portion of a tyre according to the present invention, with some parts in transparency;

[0078] FIG. 2 shows a section along the equatorial plane A-A of the tyre of FIG. 1;

[0079] FIGS. from 3 to 7 respectively show a noise-reducing sub-element according to some embodiments of the present invention.

DETAILED DESCRIPTION OF SOME EMBODIMENTS OF THE INVENTION

[0080] The features and the advantages of the present invention will be further clarified by the following detailed description of some embodiments, presented by way of example and not limitative of the present invention, with reference to the attached figures.

[0081] With reference to FIGS. 1 and 2, they show a tyre 1 (only partially shown in FIG. 1 and shown in section in FIG. 2) comprising a tread band 2 (only schematically shown) having, for purely illustrative purpose, at least three reliefs (partially shown in FIG. 1) with continuous circumferential development and axially distributed.

[0082] Exemplarily the reliefs comprise an axially central relief 3′, arranged in axially central position of the tread band, and two further reliefs 3″ axially arranged at the sides of the central relief. The central relief is defined (e.g. it is separated from the further reliefs) by a pair of grooves 15 with continuous circumferential development, arranged adjacent to, and at opposite side of, the central relief 3′. During the use of the tyre, it may occur that the relief of the tread band subjected to greater thermal rise is one of the two further reliefs (3″), due to the conditions of use of the tyre and/or the configuration of the vehicle.

[0083] Exemplarily the tyre 1 comprises a noise-reducing element 4 (FIG. 2) applied on an inner surface 5 of the tyre and extending along substantially the whole circumferential development of the inner surface 5.

[0084] Exemplarily the noise-reducing element 4 consists of a plurality (in the example twelve) of noise-reducing sub-elements 4′, having axial width (in the example also circumferential length) equal between each other, applied equidistant to each other and circumferentially in sequence along the whole circumferential development of the inner surface 5 of the tyre 1 (as shown in FIG. 2).

[0085] Exemplarily, each noise-reducing sub-element 4′ is, in the non-deformed configuration (shown in FIGS. from 3 to 7 and in the plane development of the crown portion of FIG. 1), a rectangular parallelepiped having a long side 6 arranged according to the circumferential development and a short side 7 arranged according to an axial direction (when the sub-element is applied to the tyre). In use the respective thickness is arranged radially.

[0086] Exemplarily each noise-reducing sub-element 4′ is entirely made of a sound-absorbing foam of expanded polyurethane with open cell, having a density of about 30 kg/m.sup.3. Each noise-reducing sub-element 4′ is applied on the inner surface of the tyre by a pressure sensitive adhesive layer (not shown) interposed between each sub-element and the inner surface itself.

[0087] Exemplarily each noise-reducing sub-element 4′ comprises a first face 10 (FIG. 2) entirely adjacent to, and in contact with, the inner surface 5 of the tyre 1, except for the aforementioned adhesive layer.

[0088] The noise-reducing element 4 comprises a series 8 of openings 8′ (entirely shown only in FIG. 2), arranged in axially central position, and two further series 9 of openings 9′ (only partially shown in FIGS. 1 and 3-7) arranged at axially opposite sides of the series 8 of openings.

[0089] Each opening of the series 8 and of the further series 9 is radially through and delimited by a respective boundary surface 14 having a radial development and entirely belonging to the noise-reducing element 4. Exemplarily the openings of the series 8 and of the further series 9 are axially aligned (with respect to a same series) and they have a respective section 16, perpendicular to an axis of development thereof (not shown, perpendicular to a lying plane of the openings), constant along the axis of development itself.

[0090] In one embodiment not shown, the boundary surface which delimits the openings may not be radial, for example it may have inclined cylinder shape.

[0091] The series 8 and the further series 9 of openings develop along the circumferential development of the inner surface 5 of the tyre. The openings of each series are arranged, in substantially regular way, along substantially the whole circumferential development of the inner surface (as shown for the series 8 in FIG. 2). The arrangement on the noise-reducing element of the openings of the series 8 and of the further series 9 follows an ordered scheme comprising a base module 11 repeated along the circumferential development, in substantially equispaced manner.

[0092] Exemplarily each noise-reducing sub-element 4′ comprises one and only one base module 11, the base module 11 comprising in turn a first set of openings belonging to the series 8 of openings and a pair of second sets of openings, each belonging to a respective further series 9 of openings. The series 8 and the further series 9 of openings are therefore made by the combination in sequence of the noise-reducing sub-elements 4′ along the inner circumferential development of the tyre 1.

[0093] Consequently, the openings made in the noise-reducing sub-elements shown in FIG. 1 and in FIGS. from 3 to 7 constitute, for each noise-reducing sub-element, a single base module 11 of the ordered scheme according to which the series 8 and the further series 9 of openings are arranged.

[0094] With reference to FIG. 1, which shows a noise-reducing sub-element applied on the inner surface of the tyre, the series 8 of openings (shown only by means of the base module 11) is exemplarily positioned so that an overall plant area of the openings thereof is entirely placed at the axially central relief 3′.

[0095] Still with reference to FIG. 1, each further series 9 of openings (even them shown only through the base module 11) is exemplarily positioned so that at least the 90% of an overall plant area of the respective openings thereof is placed at a respective further relief 3″.

[0096] Exemplarily each base module 11 has a first symmetry plane 100 parallel to an equatorial plane (not shown) of the tyre and a second symmetry plane 200 perpendicular to the equatorial plane of the tyre 1.

[0097] In the FIGS. 1 and 3-7 some embodiments of the base module 11 comprised in the respective noise-reducing sub-element 4′ are shown, in which the shape and/or the number of the openings of the first and of the second sets varies.

[0098] With reference to FIG. 1, the shown base module 11 comprises three circular openings belonging to the series 8 and four openings having elongated shape with a main dimension L, two by two belonging to the further series 9 of openings.

[0099] Consequently, the series 8 of openings comprises openings having the same shape and sizes and the further series 9 of openings comprise the same number of openings, with openings having the same shape, size and circumferential arrangement. Exemplarily the elongated shape of the openings 9′ of the further series 9 comprises two end portions 12 along the main dimension having a lobed shape and a central portion 13, of reduced size, which interconnects the two end portions 12.

[0100] Exemplarily the main dimension of each opening of the further series of openings 9 is parallel to the circumferential development of the tyre. Exemplarily, the diameter of the circular openings of the series 8 is equal to 3 cm, a length along the main dimension L of each opening of the further series 9 is equal to 7.5 cm, a radius of the lobed portions 12 is equal to 1.25 cm, a length of the central portion 13 is equal to 1.9 cm, and a width of the central portion 13 is equal to 1.25 cm. The noise-reducing sub-element 4′ has exemplary dimensions 22×14 cm.

[0101] Still with reference to the example of FIG. 1, a ratio between an overall volume of all the openings present on the sub-element, and an overall volume of the noise-reducing sub-element (defined by the envelope of the outer surface of the noise-reducing sub-element) is equal to about 0.23.

[0102] In FIGS. from 3 to 7 further embodiments of noise-reducing sub-elements are shown, each comprising a different base module 11. The base modules 11 differ from each other in the number and/or in the shape and/or size of the openings of the series 8 and/or of the further series 9 of openings. It is possible to observe that these openings can be circular or elongated (lobed or not) with a main dimension. In the case the openings have an elongated shape, the main dimension is preferably parallel to the circumferential development of the tyre (once the respective noise-reducing sub-element has been applied on the inner surface of the tyre itself).