BRAKING BAND OF A DISC FOR DISC BRAKE OF VENTILATED TYPE

Abstract

A braking band of a disc brake disc of a ventilated type unusually capable of avoiding vibrations which induce annoying squeals during the braking action. The braking band having two plates joined by connecting elements. At least one of the connecting elements is a fin that has an extension along an outer circumferential width, and an extension along an inner circumferential width. A section taken along a section plane having a radial and circumferential direction, section made by passing through a mean air flow point which runs through a gap, where the outer circumferential width is greater than the inner circumferential width.

Claims

1-11. (canceled)

12. A braking band of a disc for disc brake of ventilated type, comprising: said braking band extending between an inner diameter, near a rotation axis of the braking band, and an outer diameter, far from said rotation axis, said rotation axis defining an axial direction; said braking band defining a radial direction, substantially orthogonal to said axial direction, and a circumferential direction, orthogonal to said axial direction and to said radial direction, and a tangential direction punctually orthogonal to said axial direction and a radial direction; said braking band comprising two mutually facing plates; said plates comprising inner surfaces, either directly or indirectly facing and delimiting a gap; said plates being joined to each other by heat dissipating and connecting elements, also named connecting elements; said connecting elements project from a plate towards the opposite plate, thereby forming bridges which connect the plates to each other; wherein at least one of said connecting elements is a fin which is in a single piece and extends from near said inner diameter to near said outer diameter; and wherein said fin comprises a fin outer end portion located near said outer diameter, the fin outer end portion of said fin comprises a predetermined extension along the outer circumferential direction comprising an outer circumferential width; said fin comprises a fin inner end portion located near said inner diameter; said fin inner end portion of said fin comprises a predetermined extension along the inner circumferential direction comprising an inner circumferential width; wherein considering a section taken along a section plane comprising a radial and circumferential direction, section made by passing through a mean air flow point which runs through said gap, said outer circumferential width is greater than said inner circumferential width; and wherein said at least one fin comprises a shank portion which extends away from said inner diameter, said shank portion is delimited by two mutually opposite sides, wherein at least one of said shank sides is substantially directed along said radial direction; and wherein said at least one fin comprises an outer radial portion arranged near said outer radial end of said fin; wherein said outer radial portion is tapered and connected to said shank portion.

13. The braking band according to claim 12, wherein said at least one fin comprises an outer radial end, said outer radial end forms a base surface, said base surface comprises a circumferential extension having straight extension or extended arc extension parallel to the outer edge of the braking band which defines said outer diameter.

14. The braking band according to claim 12, wherein at least one of the following alternatives is provided: said at least one fin comprises a shank portion which extends away from said inner diameter, said shank portion is delimited by two mutually opposite sides, wherein both said shank sides are substantially directed along said radial direction; or said at least one fin comprises a shank portion which extends away from said inner diameter, said shank portion is delimited by two mutually opposite sides, wherein at least one of said shank sides comprises at least one shank straight stretch; or said at least one fin comprises a shank portion which extends away from said inner diameter, said shank portion is delimited by two mutually opposite sides, wherein both of said shank sides comprise mutually opposite shank straight stretches.

15. The braking band according to claim 12, wherein said at least one fin comprises an outer radial portion arranged near said outer radial end of said fin; said at least one fin comprises a shank portion arranged near said inner radial end of said fin; and at least one of the following alternatives is provided: in a section taken along a section plane comprising a radial and circumferential direction, section made by passing through a mean air flow point which runs through said gap, a section edge or perimeter of said fin from said outer radial portion is connected to said shank portion; or said outer radial portion is tapered passing near said outer diameter and going towards said inner diameter; or said shank portion comprises a width, i.e. an extension evaluated in circumferential direction, substantially constant along its entire extension which juts predominantly in radial direction; or said outer radial portion is delimited by two mutually opposite outer radial portion sides; said outer radial portion sides are arched and connect to said shank portion.

16. The braking band according to claim 12, wherein said at least one fin comprises fin connectors which connect said fin to said inner surfaces of said plate.

17. The braking band according to claim 12 wherein: said at least one fin comprises an outer radial portion arranged near said outer radial end of said fin; said at least one fin comprises a shank portion arranged near said inner radial end of said fin; wherein a section according to a section plane comprising a radial and circumferential direction, section made by passing through a mean air flow point which runs through said gap, said outer radial portion comprises a substantially rectangular or oval shape having a prevalent extension in the circumferential or tangential direction; and/or wherein said shank portion comprises a width in circumferential direction, substantially constant along all its prevalent extension in radial direction; and/or wherein said shank portion is connected to said outer radial portion substantially at half of the circumferential or tangential extension of the outer radial portion.

18. The braking band according to claim 12 wherein said braking band comprises at least one connecting element which connects said plates and comprises an extension in radial direction lower than the band height comprising at the radial distance between said inner diameter and said outer diameter; said connecting element being named a pin; wherein at least one pin is arranged directly facing at least one fin; or wherein said braking band comprises at least two pins and; wherein said at least two pins are arranged directly facing said at least one fin from opposite sides thereof.

19. The braking band according to claim 12, wherein said braking band comprises at least one connecting element which connects said plates and comprises an extension in radial direction lower than the band height comprising at the radial distance between said inner diameter and said outer diameter, said connecting element being named a pin; wherein said at least one pin is a plurality of pins; at least one of the following alternatives is provided: said plurality of pins is arranged according to three ranks, an outer rank, an intermediate rank and an inner rank; or said plurality of pins is arranged according to three ranks, an outer rank, an intermediate rank and an inner rank and at least one pin of the intermediate rank faces at least one side of said fin; or at least one pin comprises a drop-shaped section according to a section plane comprising a radial and circumferential direction, section made by passing through a mean air flow point which runs through said gap, thus defining a drop-shaped pin; or at least one pin is tapered towards said inner diameter; or at least one pin comprises in a rhombus-shaped section according to a section plane comprising a radial and circumferential direction, section made by passing through a mean air flow point which runs through said gap, thus defining a rhombus- shaped pin; or said plurality of pins is arranged according to three ranks, an outer rank, an intermediate rank and an inner rank; and wherein the outer rank comprises at least one drop-shaped pin, or comprises only drop-shaped pins; and wherein said intermediate rank comprises at least one rhombus-shaped pin, or comprises only rhombus-shaped pins; and wherein said inner rank comprises at least one rhombus-shaped pin, or comprises only rhombus-shaped pins; or said plurality of pins is arranged according to three ranks, an outer rank, an intermediate rank and an inner rank; and wherein all the pins are arranged in a quincunx.

20. The braking band according to claim 12, wherein said braking band comprises a plurality of fins; at least one of the following alternatives is provided: wherein said plurality of fins is arranged circumferentially in uniform manner along said gap providing one fin every 60 DEG; or said fins are six fins distributed circumferentially in uniform manner along said gap; or said fins are arranged in said gap in pairs of fins; or said fins are arranged in said gap in pairs of fins distributed circumferentially in a uniform manner along said gap; or said fins are arranged in said gap in pairs of fins in which at least one pin is provided between said fins of said pair of fins; or said fins are arranged in said gap in pairs of fins in which at least one pin is provided between said fins of said pair of fins and said pairs of fins with at least one interposed pin are distributed circumferentially in uniform manner along said gap.

21. A disc brake disc comprising the braking band as defined by in claim 12 and a bell associated with said braking band and adapted to connect to a wheel hub of a vehicle.

22. A vehicle comprising a disc brake disc according to claim 21.

Description

FIGURES

[0048] Further features and advantages of the device, of the brake disc and of the vehicle will be apparent from the following description of preferred embodiments thereof, by way of non-limiting examples, with reference to the accompanying figures, in which:

[0049] FIG. 1 is a partially sectioned axonometric view of a disc brake disc with a braking band according to the present invention;

[0050] FIG. 2 shows a sectioned plan view taken along a medium plane of fluid flow through the gap of the braking band in FIG. 1;

[0051] FIG. 3 is an axonometric view of an enlarged detail of the braking band section in FIG. 2;

[0052] FIG. 4 is a partially sectioned axonometric view of a disc brake disc with a braking band according to a further embodiment of the present invention;

[0053] FIG. 5 shows a sectioned plan view taken along a medium plane of fluid flow through the gap of the braking band in FIG. 4;

[0054] FIG. 6 is an axonometric view of an enlarged detail of the braking band section in FIG. 5;

[0055] FIG. 7 is a partially sectioned axonometric view of a disc brake disc with a braking band according to a further embodiment of the present invention;

[0056] FIG. 8 shows a sectioned plan view taken along a medium plane of fluid flow through the gap of the braking band in FIG. 7;

[0057] FIG. 9 is an axonometric view of an enlarged detail of the braking band section in FIG. 8;

[0058] FIG. 10 is a partially sectioned axonometric view of a disc brake disc with a braking band according to a further embodiment of the present invention;

[0059] FIG. 11 shows a sectioned plan view taken along a medium plane of fluid flow through the gap of the braking band in FIG. 10;

[0060] FIG. 12 is an axonometric view of an enlarged detail of the braking band section in FIG. 11.

DESCRIPTION OF SOME PREFERRED EMBODIMENTS

[0061] According to a general embodiment, a braking band 1 of a disc for a disc brake 2 of the ventilated type is provided.

[0062] Said braking band 1 extends between an inner diameter D1, near a rotation axis X-X of the braking band 1, and an outer diameter D2, far from said rotation axis X-X. Said rotation axis defines an axial direction X-X.

[0063] Said braking band 1 defines a radial direction R-R, which is substantially orthogonal to said axial direction X-X, and a circumferential direction C-C which is orthogonal both to said axial direction X-X and to said radial direction R-R.

[0064] Said braking band 1 comprises two plates 3, 4 facing each other.

[0065] Said plates 3, 4 comprise inner surfaces 5, 6, either directly or indirectly facing each other and delimiting a gap 7 which defines a ventilation conduit for the braking band 1.

[0066] Said plates 3, 4 comprising outer surfaces 8, 9.

[0067] Said outer surfaces 8, 9 comprise opposite flat circumferential portions, which form braking surfaces 10, 11. In other words, portions of the outer surfaces 8, 9 cooperate with brake pads housed in a brake caliper to apply a braking action when sandwiched against the braking band 1. The portion of the outer surfaces 8, 9 which is brushed or concerned by the pads defines the braking surfaces 10, 11.

[0068] Said plates 3, 4 comprise a plate body 12, 13 having an extension in axial direction X-X or plate thickness 14, 15. In other words, when observed in an axial direction, each plate 3, 4 shows a plate thickness 14, 15 which is given by the thickness in the axial direction of the plate body 12 of the plate 3, 4.

[0069] Said plates 3, 4 are joined to each other by heat dissipation elements or connecting elements 16, 17, 18 of the plates 3, 4.

[0070] Said connecting elements 16, 17, 18 are shaped as columns and/or ribs, which project from one plate towards the opposite plate in the shape of connecting bridges of the plates 3, 4.

[0071] Advantageously, at least one of said connecting elements is a fin 19 which is in one piece and extends from near said inner diameter D1 to near said outer diameter D2.

[0072] Said fin 19 comprises a fin outer end portion 20 placed near said outer diameter D1.

[0073] Said fin outer end portion 20 of said fin 19 comprises a predetermined extension along the outer circumferential direction, i.e. an outer circumferential width Lo.

[0074] Said fin 19 comprises a fin inner end portion 21 placed near said inner diameter D1.

[0075] Said fin inner end portion 21 of said fin 19 comprises a predetermined extension along the inner circumferential direction, i.e. an inner circumferential width Li.

[0076] Advantageously, considering a section taken along a section plane comprising a radial R-R and circumferential C-C direction, section made by passing through a mean air flow point which runs through said gap, said outer circumferential width Lo is greater than said inner circumferential width Li.

[0077] According to an embodiment, said at least one fin 19 comprises an outer radial end 26. Said outer radial end 26 forms a base surface 27. Said base surface 27 comprises a circumferential extension having straight extension or extended arc extension parallel to the outer edge of the braking band 1 which defines said outer diameter D2.

[0078] According to an embodiment, said at least one fin 19 comprises a shank portion 28 which extends away from said inner diameter D1. Said shank portion 28 is delimited by two mutually opposite sides 38, 39; wherein at least one of said shank sides 38, 39 is substantially directed along said radial direction R-R.

[0079] According to an embodiment, said at least one fin 19 comprises a shank portion 28 which extends away from said inner diameter D1. Said shank portion 28 is delimited by two mutually opposite sides 38, 39; wherein both said shank sides 38, 39 are substantially directed along said radial direction R-R.

[0080] According to an embodiment, said at least one fin 19 comprises a shank portion 28 which extends away from said inner diameter D1. Said shank portion 28 is delimited by two mutually opposite sides 38, 39; wherein at least one of said shank sides 38, 39 comprises at least one shank straight stretch 40.

[0081] According to an embodiment, said at least one fin 19 comprises a shank portion 28 which extends away from said inner diameter D1. Said shank portion 28 is delimited by two mutually opposite sides 38, 39; wherein both of said shank sides 38, 39 comprise mutually opposite shank straight stretches 40, 41.

[0082] According to an embodiment, said at least one fin 19 comprises an outer radial portion 29 arranged near said outer radial end 20 of said fin 19. Said at least one fin 19 comprises a shank portion 28 arranged near said inner radial end 21 of said fin 19.

[0083] According to an embodiment, in a section taken along a section plane comprising a radial R-R and circumferential C-C direction, section made by passing through a mean air flow point which runs through said gap, a section edge or perimeter of said fin from said outer radial portion 29 is connected to said shank portion 28.

[0084] According to an embodiment, said outer radial portion 29 is tapered passing near said outer diameter D2 and going towards said inner diameter D1.

[0085] According to an embodiment, said shank portion 28 comprises a width, i.e. an extension evaluated in a circumferential direction, substantially constant along its entire extension which juts predominantly in radial direction R-R.

[0086] Advantageously, said outer radial portion 29 is tapered and connected to said shank portion 28.

[0087] By virtue of the provision of a tapered radial outer portion connected to said shank portion, it is possible to significantly improve the ventilation and therefore the cooling of the disc. Indeed, the tapered radial portion of the tapered tern conveys the cooling fluid flow through the disc, thus improving the cooling efficiency of the disc itself. At the same time, the connection to the shank portion allows to have a fin which, without discontinuity, stiffens and strengthens the entire radial extension of the ventilated braking band of the disc, thereby improving the structural and dynamic performance of the disc itself.

[0088] According to an embodiment, said outer radial portion 29 is delimited by two mutually opposite outer radial portion sides 42, 43; said outer radial portion sides 42, 43 are arched and connect to said shank portion 28.

[0089] According to an embodiment, said at least one fin 19 comprises fin connectors 22 which connect said fin 19 to said inner surfaces 5, 6 of said plate 3, 4.

[0090] According to an embodiment, said at least one fin 19 comprises an outer radial portion 29 arranged near said outer radial end 20 of said fin 19. Said at least one fin 19 comprises a shank portion 28 arranged near said inner radial end 21 of said fin 19.

[0091] According to an embodiment, in a section according to a section plane comprising a radial R-R and circumferential C-C direction, section made by passing through a mean air flow point which runs through said gap, said outer radial portion 29 comprises a substantially rectangular or oval shape having a prevalent extension in the circumferential C-C or tangential T-T direction.

[0092] According to an embodiment, said shank portion 28 comprises a width in circumferential direction C-C, substantially constant along all its prevalent extension in radial direction R-R.

[0093] According to an embodiment, said shank portion 28 is connected to said outer radial portion 29 substantially at half of the circumferential or tangential extension of the outer radial portion 29.

[0094] According to an embodiment, wherein said braking band 1 comprises at least one connecting element 16, 17, 18 which connects said plates 3,4 and comprises an extension in radial direction R-R lower than the band height, i.e. at the radial distance between said inner diameter D1 and said outer diameter D2; said connecting element being named pin 16, 17, 18.

[0095] According to an embodiment, at least one pin 17 is arranged directly facing at least one fin 19.

[0096] According to an embodiment, said braking band 19 comprises at least two pins 16, 17, 18. Said at least two pins 17 are arranged directly facing said at least one fin 19 from opposite sides 36, 37 thereof.

[0097] According to an embodiment, wherein said braking band 1 comprises at least one connecting element 16, 17, 18 which connects said plates 3,4 and comprises an extension in radial direction R-R lower than the band height, i.e. at the radial distance between said inner diameter D1 and said outer diameter D2; said connecting element being named pin 16, 17, 18.

[0098] According to an embodiment, said at least one pin is a plurality of pins 16, 17, 18.

[0099] According to an embodiment, said plurality of pins 16, 17, is arranged according to three ranks, an outer rank 23, an intermediate rank 24, and an inner rank 25.

[0100] According to an embodiment, said plurality of pins 16, 17, is arranged according to three ranks, an outer rank 23, an intermediate rank 24, and an inner rank 25 and at least one pin 17 of the intermediate rank 24 faces at least one side 37, 38 of said fin 19.

[0101] According to an embodiment, at least one pin 16 comprises a drop-shaped section according to a section plane comprising a radial R-R and circumferential direction C-C, section made by passing through a mean air flow point which runs through said gap, thus defining a drop-shaped pin 16.

[0102] According to an embodiment, at least one pin 16 is tapered towards said inner diameter D1.

[0103] According to an embodiment, at least one pin 17, 18 comprise in a rhombus-shaped section according to a section plane comprising a radial R-R and circumferential direction C-C, section made by passing through a mean air flow point which runs through said gap, thus defining a rhombus-shaped pin 17, 18.

[0104] According to an embodiment, said plurality of pins 16, 17, is arranged according to three ranks, an outer rank 23, an intermediate rank 24, and an inner rank 25.

[0105] According to an embodiment, said outer rank 23 comprises at least one drop-shaped pin 16 or comprises only drop-shaped pins 16.

[0106] According to an embodiment, said intermediate rank 24 comprises at least one rhombus-shaped pin 17 or comprises only rhombus-shaped pins 17.

[0107] According to an embodiment, said inner rank 25 comprises at least one rhombus-shaped pin 18 or comprises only rhombus-shaped pins 18.

[0108] According to an embodiment, said plurality of pins 16, 17, is arranged according to three ranks, an outer rank 23, an intermediate rank 24, and an inner rank 25. All the pins 16, 17, 18 are arranged in a quincunx.

[0109] According to an embodiment, said braking band 1 comprises a plurality of pins 19.

[0110] According to an embodiment, said plurality of fins 19 is arranged circumferentially in a uniform manner along said gap 7 providing one fin 19 every 60 DEG.

[0111] According to an embodiment, said fins 19 are six fins 19 distributed circumferentially in a uniform manner along said gap 7.

[0112] According to an embodiment, said fins 19 are arranged in said gap 7 in pairs of fins.

[0113] According to an embodiment, said fins 19 are arranged in said gap 7 in pairs of fins distributed circumferentially in a uniform manner along said gap 7.

[0114] According to an embodiment, said fins 19 are arranged in said gap 7 in pairs of fins in which at least one pin 17 is provided between said fins 19 of said pair of fins.

[0115] According to an embodiment, said fins 19 are arranged in said gap 7 in pairs of fins in which at least one pin 17 is provided between said fins 19 of said pair of fins and said pairs of fins with at least one interposed pin are distributed circumferentially in a uniform manner along said gap 7.

[0116] The present invention further relates to a disc brake disc comprising a braking band 1 as defined by any one of the embodiments described above and a bell 33 associated with said braking band 1 and adapted to connect to a wheel hub of a vehicle.

[0117] The present invention further relates to a vehicle comprising a disc brake disc 2 as defined above.

[0118] An embodiment of the present invention is described by way of non-limiting example below.

[0119] According to an embodiment, a braking band 1 has an outer diameter D2 of 380 mm, an inner diameter of 228 mm, and a thickness of 34 mm.

[0120] The two plates 3, 4 are connected to each other by connecting elements 16, 17, 18 in the form of columns arranged in three rows or ranks 23, 24, 25, which are concentric and said connecting elements 16, 17, 18 are arranged in a quincunx arrangement.

[0121] Fins 19 extending for the entire height of the gap 7 are present every 60 DEG.

[0122] On the outer rank 24, the connecting elements have a shape evaluated on a mean flow plane which runs through the drop-shaped gap 7, with tapering extension directed in the radial direction R-R and facing the rotation axis X-X.

[0123] On the intermediate rank 25 and inner rank 23, the connecting elements 17, 18 have a shape, evaluated in a mean flow plane which runs through the rhomboidal gap 7.

[0124] Each rank counts 47 connecting elements 16 or 17 or 18.

[0125] The fins have dimensions L.sub.0=14.35 mm, Li=4 mm and radial length of 69 mm.

[0126] The modal analysis performed in a frequency range from 20 to 10,000 Hz (with material having a Young modulus of 123,700 MPa a Poisson ratio of 0.250 and a density of 7.205 kg/dm.sup.3 presented the following values of interest compared with the solution described in EP 2 715 179 B1 by Applicant:

TABLE-US-00001 Mode K(0; 3) 1 projection band disc frequency [Hz] 1692 according to EP 2 715179 B1 2 projection band disc frequency [Hz] 1662 according to the present invention and 1744 amplitude reduction and amplitude separation of the reduction single high sound peak into 2 lower ones

LIST OF REFERENCES

[0127] 1 braking band [0128] 2 disc brake disc [0129] 3 plate [0130] 4 plate [0131] 5 inner surface [0132] 6 inner surface [0133] 7 gap [0134] 8 outer surface [0135] 9 outer surface [0136] 10 braking surface [0137] 11 braking surface [0138] 12 plate body [0139] 13 plate body [0140] 14 plate thickness [0141] 15 plate thickness [0142] 16 outer pin connecting elements or outer rank [0143] 17 intermediate pin connecting elements or intermediate rank [0144] 18 inner pin connecting elements or inner rank [0145] 19 fin-shaped connecting elements [0146] 20 fin outer end portion [0147] 21 fin inner end portion [0148] 23 outer pin rank

[0149] 24 intermediate pin rank [0150] 25 inner pin rank [0151] 26 fin outer radial end [0152] 27 outer radial end base surface [0153] 28 fin shank portion [0154] 29 fin outer radial portion [0155] 33 bell [0156] 35 outer band edge [0157] 36 fin side [0158] 37 opposite fin side [0159] 38 shank side [0160] 39 opposite shank side [0161] 40 shank rectilinear stretch [0162] 41 shank rectilinear stretch [0163] 42 outer radial portion side [0164] 43 outer radial portion opposite side [0165] A-A braking band or brake disc rotation axis [0166] X-X rotation axis or axial direction [0167] R-R radial direction [0168] C-C tangential direction [0169] D1 inner band diameter [0170] D2 outer band diameter [0171] Lo fin outer circumferential width [0172] Li fin inner circumferential width