Ventilated type brake band for disc brakes

Abstract

Brake band for ventilated type disc brakes The present invention provides a brake band (1) for a ventilated disc brake disc (2) that avoids vibrations that induce annoying whistling noises during braking. The brake band (1) extends between an inner diameter (D1) near an axis of rotation (XX) of the brake band (1) and an outer diameter (D2) distal to the axis of rotation (XX), the axis of rotation defining an axial direction (XX). The brake band (1) defines a radial direction (RR) substantially perpendicular to the axial direction (XX) and a circumferential direction (CC) perpendicular to the axial direction (XX) and the radial direction (RR). The brake band (1) comprises two opposing plates (3, 4), the plates (3, 4) including inner surfaces (5, 6) that face each other directly or indirectly and define a gap (7), and the plates (3, 4) include outer surfaces (8, 9) that consist of flat, opposing circumferential portions that form braking surfaces (10, 11). The plates (3, 4) consist of a plate body (12, 13) or plate thickness (14, 15) extending in the axial direction (XX). The plates (3, 4) are joined to each other by heat dissipation or connecting elements (16, 17, 18, 19). The connecting elements (16, 17, 18, 19) are in the form of pillars and / or ribs that protrude from one plate toward the opposite plate, forming a bridge connecting the plates (3, 4). One of the plates (3, 4) has at least one ridge (20, 21, 22). The ridge protrudes from the plate (3, 4) into the gap (7) but does not reach the opposite plate (4, 3). This forms a portion that locally increases the thickness of the plate body (12, 13) while locally narrowing the gap (7). At least one ridge (20, 21, 22) extends from a first connection element (16, 17, 18, 19) to an adjacent connection element (16, 17, 18, 19) that connects the first connection element (16, 17, 18, 19). The at least one ridge extends along the circumferential direction (CC) and connects at least two adjacent connection elements (16, 17, 18, 19) that are arranged side by side in the circumferential direction (CC).Each assembly of ridges (20, 21, 22) extends circumferentially along a discontinuous annular path so as not to be uniformly distributed circumferentially.

Description

[Technical field]

[0001] The present invention relates to a brake band and a ventilated disc for disc brakes, in particular, but not exclusively, to applications in the automotive sector, and to vehicles equipped with said ventilated discs. [Background technology]

[0002] In a disc brake, a brake caliper is generally arranged astride the outer peripheral edge of a brake disc adapted to rotate about an axis of rotation (AA) defining an axial direction (XX). In a disc brake, a radial direction (RR) is also defined, which is substantially perpendicular to said axial direction (XX), a circumferential direction (CC) perpendicular to both said axial direction (XX) and said radial direction (RR), and a tangential direction (TT) locally, and better in time, perpendicular to both said axial direction (XX) and said radial direction (RR).

[0003] As is known, a disc for a disc brake comprises a bell adapted to associate the disc with the hub of the vehicle, from which extends an annular portion called the brake band, intended to act in conjunction with the brake pads of a caliper. In the case of ventilated type discs, the brake band is made by two plates facing each other and connected to each other by connecting elements, for example in the form of pillars or fins. The outer faces of the two plates define the opposing braking surfaces, while the inner faces, in conjunction with the pillars or fins, define air passages for cooling the disc, i.e. the passages through which air flows according to a centrifugal direction during the rotational movement of the disc itself.

[0004] The braking band is intended to work in conjunction with a caliper for a disc brake adapted to apply braking force to a vehicle, and thus exerts friction by means of the pads on the opposing surfaces of two plates, called the braking surfaces.

[0005] It is known that during braking, friction between the pads of the brake caliper and the braking surfaces of the brake band increases the amount of heat that needs to be dissipated.

[0006] The heat generated can actually cause the occurrence of several undesirable phenomena, such as, for example, deformation of the brake band, the formation of cracks on the braking surface or changes in the local state of the material forming the brake band, resulting in a deterioration of the brake band itself.

[0007] Particularly in high performance automotive applications where braking efficiency is increased, the energy to be discarded is quite high and the aforementioned need to discard the heat generated by braking action is even more felt.

[0008] Ventilated discs of the aforementioned type have undergone continuous evolution over the years, in particular with regard to the number and shape of the so-called ventilation channels which define the gap formed by the two plates axially facing each other.

[0009] Among the known breathable disks, so-called "pillar" disks have been shown to be particularly efficient in terms of heat dissipation, i.e. cooling, in which the air passages are internally restricted by specific pillar connecting elements, which are defined as "pillars" laterally connecting two plates, and which have limited or virtually no deformation in radial and circumferential length relative to the axial extension of the pillars.

[0010] For example, a "pillar" ventilated disk is known from EP 1 373 751 B1, in which the pillars are geometrically arranged along three concentric circumferences with different radii coaxial with the disk to form three "ranks", and on a cross section parallel to the two plates and along their central plane, the pillars have different types of cross sections (e.g. pins with a "diamond" cross section in the intermediate and inner ranks; "droplet-shaped" pillars in the outer ranks).

[0011] Other ventilated discs with a "pillar" structure are known, for example from WO 2004 / 102028 and US Pat. No. 5,542,503.

[0012] Known ventilated discs include so-called "fin" or "tab" discs, in which the air passages are confined internally by specific connecting elements, elongated along a main direction oriented, for example, parallel to the radial direction (RR), or by helices, connecting the two plates laterally.

[0013] Likewise, it is known that the braking action performed by the pads against the braking surface of the disc generates heat and therefore leads to a temperature rise of the disc, even to the point of making the disc itself white-hot, especially in the case of severe performance. The temperature of the disc rises during braking, which leads to deformation of the disc and poor contact between the pads and the braking surface. Furthermore, the friction material of the pads undergoes a kind of vitrification and becomes contaminated by the material of the disc.

[0014] It has also been found that the highest temperatures are reached in the annular centre of the braking surface, i.e. in the annular centre of the outer circumferential surface of each plate, and during the life of the disc, such zone is prone to cracking.

[0015] In order to avoid the above-mentioned drawbacks, there is a particular need felt in this sector, on the one hand, to increase the efficiency of the dissipation of the heat generated by braking, so as to limit the temperature reached by the disc during and after braking, and, on the other hand, to increase the mechanical resistance of the central part of the braking band.

[0016] Several solutions are known from WO2004 / 102028, WO2002064992, US7066306, US7267210, US2006 / 0243546, US2004 / 0124047, US6367599, US5542503 and US4865167. Although satisfactory from various points of view, these known solutions do not allow a compromise between the desired mechanical resistance in the central annular zone of the braking band and the contrasting need to maximize in the same zone an air flow capable of eliminating the strong local temperature rise caused by the braking action.

[0017] It should be noted, however, that ventilated discs of the above type do not, in themselves, offer a solution to a further problem which arises at the same time as the problem mentioned above and which must be solved at the same time, namely a problem which may affect disc brakes, and in particular disc brakes equipped with ventilated discs.

[0018] As is known, during the operation of the brakes, in particular the disc and the brake band, may mechanically vibrate at different frequencies that correlate with different vibration modes of the disc itself. Such vibrations of the disc may result, for example, from resonances caused by vibrations of objects mechanically coupled to the disc that are stressed during the braking step, if the vibration frequency of such objects coincides with or is sufficiently close to the vibration frequency of the disc.

[0019] It is also known that the above vibrations produce audible noises, in particular annoying whistling-like noises, when the resonant frequency is in the audible range (for example between 2 and 9 kHz followed by a more or less sharp whistling sound).

[0020] A need therefore arises to devise a solution to reduce or eliminate such whistling noise by constructing a device that "shifts" the vibration frequency of the disk to a value different from that which was excited.

[0021] For disks with structures different from the "pillar" structure described above, several solutions are known.

[0022] For example, IT 1 273 754 has a brake band with protrusions projecting on the inside of the plates, at a specific position and mass, towards the gap between the two plates in order to reduce the vibrations and subsequent noise that occur.

[0023] Other breathable discs having a structure adapted to reduce annoying vibration phenomena are known, for example, from US Pat. No. 4,523,666.

[0024] Document US 3,983,973 from Knorr-Bremse GmbH shows a brake disc comprising a pair of friction plates spaced apart from each other to form an air passage. A brake force may be applied against said plates by a brake pad brake gasket. The two friction plates are connected to each other by a number of ribs or flow guide fins, forming an air passage between them. Strips of vibration-damping material are arranged in radial grooves formed on the opposing faces of the friction plates. These inserts are formed by metal elements that damp vibrations and have a coefficient of expansion greater than that of the ferrous material from which the friction plates are made, e.g. lead, bronze or copper.

[0025] A similar solution is known from US2009 / 035598.

[0026] It is known from document US2012111692 to couple a passive damper of the scooter type to a braking device in order to reduce vibrations.

[0027] Solutions are known from US 6,131,707, WO 2016 / 020820, WO 2017 / 153902, WO 2017 / 153873, EP 0318687, WO 2011 / 058594, WO 2006 / 105131, US 2006 / 219500, US 6,145,636. US2010 / 122880, US6325185, US4523666, US5004078, SI23, 474, GB2060796, DE102013210700, EP3, 421833, WO2015 / 092671, GB2286438, DE10200405, 6645, EP2192321, WO2008 / 078352, US3983973, DE202006017092, US2009 / 0000884, DE202015102580 for providing connections between plates of a brake band that are circumferentially non-uniformly arranged to reduce vibration excited by braking action and to increase ventilation in the gap.

[0028] However, these distributions of the connecting elements of the plates create structural inhomogeneities which can generate quite unwanted stresses concentrated in the brake band under certain conditions of braking operation.

[0029] A need therefore arises for new constructions of ventilated discs that can simultaneously provide both efficient cooling performance and vibration and noise minimization characteristics during braking steps, while avoiding causing concentrated stresses in the brake band that could impair its integrity and lifespan.

[0030] The above-mentioned known examples of breathable discs and associated brake bands do not adequately meet all the stated and highly desirable needs.

[0031] The same applicant's document EP 2 715 179 B1 seeks to partially solve these problems and in particular to reduce the frequencies of vibration modes of the braking band which lead to vibrations outside the plane of the plates of the band themselves, in particular by having ridges arranged between the connecting elements which overhang the gap.

[0032] Although satisfactory from many points of view, this known solution does not completely solve the problem, and it is particularly emphasized how there is a felt need to find a solution that allows for the shape of the surfaces that delimit the gaps in the brake band.

[0033] Therefore, there remains a strong need to increase the mass of the brake band near its outer edges to reduce "out-of-plane" type vibration modes of the brake band which, when excited, have a significant adverse effect on brake performance.

[0034] At the same time, the need to maintain a distance between the ridges and the connecting elements, especially near the outer edge of the disc, remains strongly felt in order to simplify the manufacturing process of the core, which allows for example to make the brake band by moulding. Since the shape of the pillars is achieved by the core, which geometrically represents the space between one pillar and the other, it is required to ensure that the sand for the core has a minimum cross-section so that it can fill all the spaces that form the gaps, and furthermore, said core has a minimum cross-section that allows it to give its own structural resistance sufficient for its handling and for the melting of the brake band.

[0035] Furthermore, there is a strong felt need to avoid large annular areas of gap without connecting elements or projections, and thus to avoid poor distribution of temperature over the braking band, which could lead to disc vibrations or other out-of-balance phenomena.

[0036] The problem underlying the present invention is therefore to devise a braking band and a disc for a disc brake, having structural and functional characteristics such as to meet the aforementioned needs while avoiding the drawbacks mentioned with reference to the known art. Summary of the Invention

[0037] It is an object of the present invention to provide a braking system which has a reduced tendency to produce these vibration waves and the subsequent whistling noise.

[0038] These and other objects and advantages are achieved by a brake band according to claim 1, by a disc brake disc according to claim 9 and by a vehicle according to claim 10.

[0039] Particular advantageous embodiments are the subject matter of the dependent claims.

[0040] From the analysis of this solution it emerged how the proposed solution makes it possible to achieve a superior braking comfort with respect to prior art solutions and therefore a reduction in vibrations, in particular the absence of vibrations due to whistling noise.

[0041] Furthermore, the proposed solution maintains a very high, and in some embodiments even improved, disc cooling efficiency, for example the efficiency is strongly improved by the increased turbulence of the air flow through the gaps of the brake band, i.e. turbulence caused by the particular shape of the circumferentially extending ridges, arranged between the connecting elements, in the plate(s).

[0042] Furthermore, the proposed solution makes it possible to increase the mass of the brake band located near its outer edge in order to reduce the "out-of-plane" type of vibration manner of the brake band, which, when excited, has a significant adverse effect on the performance of the brake.

[0043] Again further, the proposed solution allows to ensure a distance between the ridge and the connecting element, especially near the outer periphery of the disc, thus simplifying the manufacturing process. For example, a minimum distance to be ensured was found between the connecting element and the ridge (variable from 5 to 7 mm, typically 6 mm) for a convenient realization of the casting core from which the brake band is made: since the geometry of the connecting element is achieved by the core, which geometrically represents the space between one connecting element and the other, it is necessary to ensure a minimum cross section so that the casting sand can fill all the space, and also to guarantee the structural resistance of the core itself.

[0044] Again further, the proposed solution makes it possible to avoid large annular areas of gap without connecting elements or ridges and therefore to avoid poor distribution of temperature on the braking band which would generate disc vibrations or other out-of-balance phenomena.

[0045]

[0048] . Again further, the proposed solution allows for increased mass near the outer edge whilst avoiding blocking or narrowing the air passages, whilst at the same time structurally strengthening the band to limit crack formation and propagation.

[0046] Again further, the proposed solution may ensure increased resistance to braking due to high temperatures.

[0047] Again further, the proposed solution results in ridges which allow further increasing the surface available for heat exchange. [Brief description of the drawings]

[0048] Further features and advantages of the device, disc brake and vehicle will become apparent from the following description of preferred, non-limiting embodiments thereof, with reference to the accompanying drawings.

[0049] [Figure 1] FIG. 1 is an axial view of a brake band according to the invention. [Diagram 2] FIG. 2 is a plan view of the brake band of FIG. 1, taken along the central flow plane of the fluid flowing through the gap. [Diagram 3] FIG. 3 is an enlarged detail view of a cross section of the brake band of FIG. [Figure 4] FIG. 4 is an axial view of a detail of the section of FIG. [Diagram 5] FIG. 5 shows a cross section of the brake band in FIG. 1 along a plane including the axial and radial directions, in which further ridge shapes are highlighted. [Figure 6] FIG. 6 shows a cross section of the brake band of FIG. 1 along a plane including the axial and radial directions, in which the shape of the ridges is highlighted. [Figure 7] FIG. 7 is an axial and partial cross-sectional view of the brake band of FIG. [Figure 8] FIG. 8 is a cross-sectional view of a brake disc constituting a brake band according to the present invention, taken along a plane including the axial and radial directions. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0050] According to a general embodiment, a disc braking band 1 for a disc brake 2 of the ventilated type is provided.

[0051] The brake band 1 extends between an inner diameter D1 close to a rotation axis XX of the brake band 1 and an outer diameter D2 remote from said rotation axis XX. The rotation axis defines an axial direction XX.

[0052] The brake band 1 defines a radial direction RR substantially perpendicular to the axial direction XX, and a circumferential direction CC perpendicular to the axial direction XX and the radial direction RR.

[0053] The brake band 1 has two plates 3, 4 facing each other.

[0054] The plates 3 , 4 face each other directly or indirectly and have inner surfaces 5 , 6 defining a gap 7 which defines a ventilation duct for the brake band 1 .

[0055] The plates 3,4 have outer surfaces 8,9.

[0056] Said outer surfaces 8, 9 consist of flat, mutually opposed circumferential portions which form braking surfaces 10, 11. In other words, a portion of the outer surfaces 8, 9 cooperates with a brake pad received in a brake caliper to provide a braking action when pinched against the brake band 1, and the portion of the outer surfaces 8, 9 which is brushed or rolled in by the pad defines the braking surface 10, 11.

[0057] Said plates 3, 4 have plate bodies 12, 13 extending in an axial direction XX and having a plate thickness 14, 15. That is to say, evaluated in the axial direction, each plate 3, 4 exhibits a plate thickness 14, 15 given by the thickness in the axial direction of the plate body 12 of the plate 3, 4.

[0058] Said plates 3,4 are joined to one another by heat dissipation or connecting elements 16,17,18 of the plates 3,4.

[0059] Said connecting elements 16, 17, 18 are in the form of pillars and / or ribs which project from one plate towards the opposite plate in the form of a bridge connecting the plates 3, 4.

[0060] At least one of the plates 3,4 includes at least one ridge 20,21 which projects from said plate 3,4 into said gap 7 without reaching the opposite plate 4,3.

[0061] Said ridges 20, 21 form at least one local constriction of said gap 7. In other words, traveling through said gap 7 and reaching said ridges 20, 21, a reduction in the cross section of the width of the gap 7 in the axial direction XX is encountered.

[0062] The ridges 20, 21 form at least one thickening of the plate body 1213 and thus cause a local increase in the plate thickness 14, 15. That is to say, considering the thickness of the plate body in the axial direction XX, the thickness 14, 15 increases at the ridges 20, 21.

[0063] According to a typical embodiment, a brake band 1 of a disc 2 for a ventilated type disc brake extends between an inner diameter D1 close to an axis of rotation XX of the brake band 1 and an outer diameter D2 remote from said axis of rotation XX, said axis of rotation defining an axial direction XX.

[0064] The brake band 1 is characterized in that it defines a radial direction RR substantially perpendicular to the axial direction XX, a circumferential direction CC perpendicular to the axial direction XX and the radial direction RR, and a tangential direction TT perpendicular to the axial direction XX and the radial direction RR.

[0065] The brake band 1 has two plates 3 and 4 facing each other.

[0066] The plates 3, 4 are directly or indirectly opposed and comprise inner surfaces 5, 6 defining a gap 7.

[0067] The plates 3, 4 have plate bodies 12, 13 having a predetermined length in the axial direction XX or a predetermined plate thickness 14, 15.

[0068] The plates 3, 4 are joined to one another by heat dissipation and connection elements 16, 17, 18 (also called connection elements).

[0069] Said connecting elements 16, 17, 18 are formed as pillars and / or ribs and / or fins protruding from one plate towards the opposite plate and forming bridges connecting the plates 3, 4 to one another.

[0070] At least one of the plates 3, 4 is characterized in that it comprises at least one ridge 20, 21 which protrudes from said plate 3, 4 into said gap 7 without reaching the opposite plate 4, 3, thereby forming at least one local narrowing of said gap 7 and the thickness of the plate body 12, 13 and thereby forming a local increase in the plate thickness 14, 15.

[0071] Said at least one ridge 20,21 remains separate from the respective connecting element 16,17,18 and the thickness of the at least one plate 3,4 with respect to said at least one ridge 20,21 is substantially equal to said predetermined plate thickness 14,15.

[0072] Advantageously, said at least one ridge 20 extends forming at least two separate ridge branches 31 , 32 .

[0073] According to one embodiment, the thickness of said at least one plate 3,4 between said at least two ridge branches 31,32 is substantially equal to said predetermined plate thickness 14,15.

[0074] According to one embodiment, said inner surfaces 5, 6 are flat surfaces.

[0075] According to one embodiment, said plates 3,4, comprise outer faces 8,9, which consist of flat opposed annular portions forming braking surfaces 10,11. The distance between said inner faces 5,6 and said braking surfaces 10,11 defines said predetermined plate thickness 14,15.

[0076] According to one embodiment, the maximum axial width or axial extension of said gap 7 is reached between said at least one ridge 20, 21 and each adjacent connecting element.

[0077] According to one embodiment, said at least one ridge 20 and its at least two distinct ridge branches 31, 32 have a symmetrical shape with respect to a plane containing the axial direction XX and the radial direction RR.

[0078] According to one embodiment, said braking band 1 has an outer band edge 35 at said outer band diameter D2. Viewed in a plane containing the radial direction RR and the circumferential direction CC, said at least one ridge 20 and its at least two further branches 31, 32 form a bifurcated ridge 3, 4 which is "V" shaped and forms a recess facing the outer edge of the disc.

[0079] According to one embodiment, seen in a plane formed by the radial direction RR and the circumferential direction CC, said at least one ridge 20 and its at least two distinct branches 31, 32 form a bifurcated ridge 3, 4, said bifurcated ridge 3, 4 being crescent shaped.

[0080] According to one embodiment, said at least one ridge 20 defines a cylindrical ridge central body 36 from which said at least two distinct ridge branches 31, 32 project.

[0081] According to one embodiment, the extensions of the at least two ridge branches 31 , 32 are arranged straddling at least one connecting element 16 .

[0082] According to one embodiment, said braking band 1 comprises at least one further ridge 21 .

[0083] According to one embodiment, at least one extension of said at least two branches 31 , 32 intersects with said at least one further ridge 21 .

[0084] According to one embodiment, said braking band 1 comprises at least two further ridges 21 arranged on the sides of the connecting element 16 .

[0085] According to one embodiment, each extension of said at least two branches 31 , 32 is intersected by at least one further ridge 21 .

[0086] According to one embodiment, said at least one further ridge 21 is drop-shaped, as viewed in the plane formed by the radial direction RR and the circumferential direction CC.

[0087] According to one embodiment, said at least one further ridge 21 has a further ridge tapered extension 37 tapering in a radial direction RR, preferably directed towards said axis of rotation XX.

[0088] According to one embodiment, said at least one further ridge 21 is a plurality of further ridges 21 .

[0089] According to one embodiment, said at least one further ridge 21 is a plurality of further ridges 21 arranged near the band outer edge 35 .

[0090] According to one embodiment, said at least one further ridge 21 is a plurality of further ridges 21 evenly distributed around the circumference.

[0091] According to one embodiment, the at least one further ridge 21 is a plurality of further ridges 21 arranged between a plurality of connecting elements 16 .

[0092] According to one embodiment, the at least one ridge 20 and its at least two separate ridge branches 31 , 32 are a plurality of ridges 20 each having a respective at least two separate ridge branches 31 , 32 .

[0093] According to one embodiment, said at least one ridge 20 and its at least two distinct ridge branches 31, 32 are a plurality of ridges 20 evenly distributed around the circumference.

[0094] According to one embodiment, the at least one ridge 20 and its at least two distinct ridge branches 31 , 32 are a plurality of ridges 20 at least partially disposed between connecting elements 17 .

[0095] According to one embodiment, at least one circumference concentric with the axis of rotation XX of the braking band 1 , arranged on said inner surfaces 5 , 6 and intersecting said connecting elements 17 of the inner or intermediate rank, also intersects said at least one ridge 20 .

[0096] According to one embodiment, at least one circumference concentric with the axis of rotation XX of the braking band 1 arranged on said inner faces 5, 6 and intersecting said connecting elements 16 of the outer rank also intersects said at least one further ridge 21.

[0097] According to one embodiment, viewed in a plane formed by the radial direction RR and the circumferential direction CC, said at least one ridge 20 and its at least two separate branches 31, 32 form a bifurcated ridge 3, 4, said bifurcated ridge 3, 4 having a rounded outer ridge surface 38 connected to said inner surface 5 or 6 and protruding therefrom into the gap 7.

[0098] According to one embodiment, viewed in a plane including the radial direction RR and the circumferential direction CC, the at least one further ridge 21 has a rounded further ridge outer surface 39 connected to the inner surface 5 or 6 and protruding therefrom into the gap 7.

[0099] According to one embodiment, the connection elements 16, 17, 18 are grouped in at least two circumferentially arranged rows or ranks 23, 24, 25. A first one of the ranks 23 is arranged radially or inwardly towards the axis XX near the inner diameter D1. A second one of the ranks 24 is arranged further radially from the axis XX near the outer diameter D2.

[0100] According to one embodiment, at least one third of the ranks 24 are radially disposed between the first inner row 23 and the second outer row 24 .

[0101] According to one embodiment, said second connecting element 16 of said rank 24 has three ridges 20, 21 for each plate facing it on three sides.

[0102] According to one embodiment, said at least one ridge 20 or 21 is at least a plurality of ridges, each of said plurality of ridges 20 or 21 being arranged between connecting elements 16 or 17 of the same rank 23, 24.

[0103] According to one embodiment, said at least one ridge 20 or 21 projects into said gap 7 from only one of said plates 3 , 4 .

[0104] According to one embodiment, said at least one ridge 20 or 21 is at least two ridges 20 or 21 , said at least two ridges 20 or 21 protruding from both of said plates 3 , 4 into said gap 7 .

[0105] According to one embodiment, said at least one ridge 20 or 21 is at least two ridges 20 or 21, said at least two ridges 20 or 21 protruding from both said plates 3, 4 into said gap 7 and facing each other.

[0106] According to one embodiment, the at least one ridge 20 or 21 is at least two ridges 20 or 21, which protrude into the gap 7 from both plates 3, 4 and are at least partially offset from each other.

[0107] According to one embodiment, at least some of said connecting elements 16, 17, 18 are fins or ribs having an elongated shape in a plane substantially parallel to the air flow along the gap 7, for example in a radial direction RR.

[0108] According to one embodiment, said connecting element 16 close to the band outer diameter D2 or outer rank 24 has an elongated drop-shaped cross section in a plane substantially parallel to the air flow along the gap 7 and in the radial direction RR.

[0109] According to one embodiment, at least two of said connecting elements 17, 18 have, on a plane substantially parallel to the air flow along the gap 7, a rhombus or diamond-shaped cross section 27 with four vertices 28 joined by four side surfaces 29, said side surfaces delimiting said cross section being substantially rectilinear in shape.

[0110] According to one embodiment, all of said ridges 20, 21 are arranged in a circular portion of said gap 7 near said band outer diameter D2.

[0111] According to one embodiment, all of said ridges 20, 21 are arranged in the circular portion of said gap 7 near which an outer rank 24 of a connecting element 16 is present.

[0112] The invention also relates to a disc brake disc 2 comprising a brake band 1 according to any one of the above-mentioned embodiments.

[0113] The invention likewise relates to a vehicle equipped with a brake band 1 according to any one of the above-described embodiments.

[0114] Those skilled in the art may make some modifications and adaptations to the above-described embodiments and may substitute other functionally equivalent elements to meet accidental and specific needs, without, however, departing from the scope of the following claims.

[0115] The clusters of ridges 20, 21 arranged close to one another form groups of ridges 20, 21 arranged in the circumferential direction and therefore have a circumferential discontinuity concentrated near the outer diameter D2 of the brake band, forming a distribution adapted to avoid the presence of vibration modes of the brake band 1 which, if arranged in sympathetic relation, would produce nuisance sounds or whistling noises, which could create an uneven distribution of the clusters of ridges.

[0116] Hereinafter, an embodiment of the present invention will be described.

[0117] According to one embodiment, the brake band 1 has an outer diameter D2 of 415 mm, an inner diameter of 295 mm and a thickness of 33 mm.

[0118] The gap 7, i.e. the air passage, has an estimated height in the axial direction XX of 12.6 mm.

[0119] The two plates 3, 4 are connected to each other by connecting elements 16, 17, 18 in the form of rows arranged over three concentric rows or ranks 23, 24, 25, said connecting elements 16, 17, 18 being arranged according to a staggered arrangement.

[0120] The connecting elements of the outer rank 24 have the shape of a droplet evaluated on the average flow surface moving through the gap 7, are oriented according to a radial direction RR and have a tapered extension facing the axis of rotation XX.

[0121] The connecting elements 17, 18 of the middle rank 25 and the inner rank 23 have a diamond shape evaluated on the mean flow plane moving through the gap 7.

[0122] Each rank has 47 connected elements, 16, 17 or 18.

[0123] In the outer rank 23, there is a further ridge 21 between each connecting element 16. Said further ridge 21 has a drop-shaped shape in a plane containing the radial direction RR and the circumferential direction CC and has a tapered extension oriented according to the radial direction RR and facing the axis of rotation XX.

[0124] The ridge 20 is present at an intermediate rank 25 between each connecting element 17. Said further ridge 20 has, in a plane containing the radial direction RR and the circumferential direction CC, a branched shape 3, 4, i.e. a cylindrical central body from which first and second ridge branches 31, 32 project separately from each other.

[0125] The ridges 20 have an axial length of 3.4mm. The base of the ridges 20 has a radius of 4mm. The overall height of the ridge 20 feature is 9.7mm and the overall width including the branches is 13.5mm.

[0126] The outer surface 38 of the ridge 20 is joined to the flat inner surface 5 or 6 at a radius of 2 mm.

[0127] A modal analysis carried out in the frequency range 20-10,000 Hz (using a material with Young's modulus of 112000 MPa, Poisson's ratio of 0.263 and density of 7.113 kg / dm) showed the following noteworthy values ​​compared to the solution described in EP 2 715 179 B1 of the same applicant:

[0128] [Table 1] [Explanation of symbols]

[0129] 1: Brake band 2: Disc brake disc 3: Plate 4: Plate 5: Inside 6: Inner 7: Gap 8: Exterior 9: Outer surface 10: Braking surface 11: Braking surface 12: Plate body 13: Plate body 14: Plate thickness 15: Plate thickness 16: Connected components 17: Connecting elements 18: Connecting elements 20: Ridge 21: Ridge 23: Rank 24: Rank 25: Rank 26: Pillar 27: Fins or ribs 28: rhombus or diamond with four vertices 29: Diamond-shaped side 31: First ridge branch 32: 2nd ridge branch 33: Bell 3, 4: Branched ridge 35: Outer band edge 36: Central Ridge 37: Further ridge tapered extension 38: Outer ridge 39: Further outer ridge AA: Axis of rotation of brake band or brake disc XX: Rotational or axial direction RR: Radial direction CC:Tangential direction D1: Band inner diameter D2: Band outer diameter

Claims

1. A brake band for a disc brake of a ventilated type, comprising: the brake band extends between an inner diameter proximate to an axis of rotation (X-X) of the brake band and an outer diameter distal to the axis of rotation (X-X), the axis of rotation (X-X) defining an axial direction; the brake band defines a radial direction (R-R) perpendicular to the axial direction, a circumferential direction (C-C) perpendicular to the axial direction and the radial direction (R-R), and a tangential direction (T-T) perpendicular to the axial direction and the radial direction (R-R); The brake band includes two opposing plates; the two opposing plates include inner surfaces that are directly or indirectly opposed and define a gap between the two opposing plates; The two opposing plates have a plate body having a predetermined plate thickness in the axial direction, The two opposing plates are joined to each other by a plurality of connecting elements that serve both as heat dissipation and connection; the plurality of connecting elements are formed as posts, ribs and / or fins protruding from one of the two opposing plates towards the opposite plate, thereby forming bridges connecting the two opposing plates to each other; one of the two opposing plates comprises at least one ridge protruding from the one plate into the gap but not reaching the opposite plate, thereby forming a local narrowing of the gap and a local increase in the predetermined plate thickness of the plate body; the at least one ridge remains separate from the plurality of connecting elements; a plate thickness of at least one of the two opposing plates around the at least one ridge is equal to the predetermined plate thickness; the at least one ridge extends forming at least two ridge branches; The at least two ridge branches are disposed across at least one of the plurality of connecting elements.

2. A plate thickness of at least one of the two opposing plates between the at least two ridge branches is equal to the predetermined plate thickness; The two opposing plates each have an inner surface and an outer surface; the outer surface includes flat opposed annular portions that define a braking surface; a distance between the inner surface and the outer surface defines the predetermined plate thickness; The brake band is the inner surface is a flat surface; 2. The braking band according to claim 1, further comprising at least one of the following features: (b) an axial width of the gap is greatest between the at least one ridge and an adjacent one of the plurality of connecting elements.

3. The at least one ridge and the at least two ridge branches have a shape that is symmetrical with respect to a plane that includes the axial direction and the radial direction (R-R), The brake band is the brake band having an outer band edge at the outer diameter; When viewed in a plane containing the radial direction (R-R) and the circumferential direction (C-C), the at least one ridge and the at least two ridge branches form a bifurcated ridge, the bifurcated ridge being "V" shaped and forming a concave facing an outer edge of the band; When viewed on a plane containing the radial direction (R-R) and the circumferential direction (C-C), the at least one ridge and the at least two ridge branches form a bifurcated ridge, and the bifurcated ridge is crescent-shaped.

2. The braking band of claim 1, wherein the at least one ridge comprises a cylindrical ridge central body from which the at least two branches project, at least one of feature (f), or a combination of features (c)-(f).

4. The braking band has at least one further ridge, The brake band is Feature (g); wherein an extension of at least one of the at least two branches intersects with the at least one further ridge; the braking band including at least two additional ridges disposed on sides of the plurality of connecting elements; each of the at least two branch extensions intersecting with at least one further ridge; feature (j), wherein, when viewed in a plane containing the radial direction (R-R) and the circumferential direction (C-C), the at least one further ridge is drop-shaped; 2. A braking band according to claim 1, wherein the at least one further ridge has at least one of feature (k), or a combination of features (g)-(k), wherein the at least one further ridge has a tapered extension that is tapered in the radial direction (R-R).

5. The at least one further ridge is a plurality of further ridges; The brake band is the at least one additional ridge being a plurality of additional ridges (21) disposed near an outer edge of the band; the at least one additional ridge being a plurality of additional ridges evenly distributed around a circumference; the at least one additional ridge is a plurality of additional ridges disposed between the plurality of connecting elements; the at least one ridge and the at least two ridge branches are a plurality of ridges each having at least two ridge branches; the at least one ridge and the at least two ridge branches are a plurality of ridges evenly distributed around a circumference; the at least one ridge and the at least two ridge branches are ridges disposed at least partially between the connecting elements; at least one circumference concentric with the axis of rotation (X-X) of the brake band, disposed on the inner surface and intersecting the plurality of connecting elements of an inner rank or an intermediate rank, intersecting the at least one ridge; at least one circumference concentric with the axis of rotation (X-X) of the brake band, disposed on the inner surface and intersecting an outer rank of the plurality of connecting elements, intersecting the at least one further ridge; When viewed in a plane containing the radial direction (R-R) and the circumferential direction (C-C), the at least one ridge and the at least two ridge branches form a bifurcated ridge, the bifurcated ridge projecting from the inner surface into the gap with a rounded outer ridge connected to the inner surface; 5. A braking band according to claim 4, wherein, viewed in a plane containing the radial direction (R-R) and the circumferential direction (C-C), the at least one further ridge has a rounded further ridge outer surface connected to the inner surface and protruding from the inner surface into the gap, at least one of feature (u), or a combination of features (l)-(u).

6. The plurality of connection elements are grouped into at least two circumferentially arranged ranks, a first rank of the at least two ranks is an inner rank arranged inwardly in the radial direction (R-R) or towards the axis of rotation (X-X) near the inner diameter (D1), a second rank of the at least two ranks being an outer rank disposed further radially from the axis of rotation (X-X) near the outer diameter (D2); The brake band further comprises: at least one third rank radially disposed between the inner rank and the outer rank; each connecting element of the outer rank includes three ridges or combinations of ridges and further combinations of ridges for each plate facing the connecting element on three sides; the at least one ridge is at least a plurality of ridges, each of the at least a plurality of ridges being disposed between the connecting elements of the same rank; the at least one ridge or the at least one further ridge protruding into the gap from only one of the two opposing plates; the at least one ridge or the at least one further ridge is at least two ridges, the at least two ridges protruding into the gap from both of the two opposing plates; the at least one ridge or the at least one further ridge is at least two ridges, the at least two ridges projecting from both of the two opposing plates into the gap and opposing each other; 2. A braking band according to claim 1, wherein the at least one ridge or the at least one further ridge is at least two ridges, the at least two ridges projecting from both of the two opposing plates into the gap and at least partially offset from one another, comprising at least one of feature (bb), or a combination of features (v)-(bb).

7. At least some of the plurality of connecting elements are fins or ribs having an elongated shape in the radial direction (R-R) on a plane parallel to the air flow along the gap, The brake band is feature (cc), wherein the connecting element proximate the outer diameter or the outer rank has an elongated, drop-shaped cross section in the radial direction (R-R) on a plane parallel to the flow of air along the gap; and wherein at least two of the plurality of connecting elements have a rhombus or diamond-shaped cross section on a plane parallel to the flow of air along the gap, the cross sections having four vertices joined by four sides, the sides being linear in shape. all of the ridges are disposed in a circular portion near the outer diameter of the gap; 7. The braking band according to claim 6, comprising at least one of features (ff), or a combination of features (cc)-(ee), wherein all of said ridges are disposed in a circular portion of said gap adjacent to said outer ranks of said plurality of connecting elements.

8. A disc brake disc having a brake band as defined in claim 1.

9. A vehicle including the brake band described in claim 1.

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