Disc for disc brake, method for making a disc for disc brake and mounting kit

Abstract

A disc for disc brake is described comprising a braking band (200), a bell (204) and a system for the radial connection of the bell (204) to the braking band (200). The connection system comprises at least one through-hole (210) made in an annular bell wall (206), at least one band seat (212) made in an inner annular surface (202) of the braking band (200), and at least one pin (214) at least partially inserted into the band seat (212) through the through-hole (210) of the bell wall (206) to bind the braking band (200) in rotation with the bell (204). The connection system further comprises a bushing (216) fitted on a lateral surface of the pin (214) and arranged through the through-hole (210), which has a flange (218) protruding from the hole (210) at least partially extending in a gap (208) between the annular bell wall (206) and the inner annular surface (202) of the braking band (200) overlapping an edge (220) of the through-hole, and an annular region (222) for grasping the pin, which are adapted to retain the pin (214) in a condition permanently coupled to the bell (204). Methods for making a disc for disc brake and a mounting kit for a disc for disc brake are further described.

Description

[0001] Disc for disc brake, method for making a disc for disc brake and mounting kit

[0002] Technical field

[0003] The present invention relates to the field of disc brakes in general; in particular, the invention relates to a disc for disc brake, a method for making a disc for disc brake, and a mounting kit for disc brake.

[0004] Background art

[0005] The embodiments of discs for disc brakes known nowadays involve making two parts: a braking band, on which the disc brake caliper acts to generate braking torque, and the bell, fixed to the wheel hub and associated with the braking band.

[0006] The connection between band and bell is very important because it ensures the transfer of braking torque from band to bell (and from the latter to the wheel hub).

[0007] Solutions are known in which the bond in rotation between band and bell is achieved by systems which involve braking band teeth which couple in respective bell seats; the axial bond, on the other hand, is achieved by means of retainer elements capable of axially retain the teeth in the respective seats thereof. Such embodiments are particularly simple and cost- effective.

[0008] However, they have some drawbacks, such as, for example, a particularly onerous tensional state acting on the band teeth, especially in the band ring connection zone.

[0009] The prior art further includes solutions to radially bind the bell in rotation to the band.

[0010] In a first example, the bell may be bound to the band by means of a threaded coupling between a fastening element and the bell.

[0011] However, the threaded coupling has the disadvantage that the fastening element may slip off during disc operation due to vibration. Another disadvantage relates to the high complexity of making the various elements due to the need to make threaded regions in the fastening element and the bell.

[0012] In a further example, the bell may be bound to the band by means of a shape coupling achieved by means of a fastening element inserted inside the band and cast into the bell.

[0013] Disadvantageously, the solution which involves the casting of the fastening element has high assembly complexity. Furthermore, should it be necessary to separate the bell from the band, for example, for maintenance operations, it will be necessary to break the bell so that the fastening element cast therein may be removed.

[0014] Summary of the invention

[0015] It is an object of the present invention to provide solutions for the connection between the braking band and the bell of a disc brake which reduce the manufacturing and assembly complexity with respect to the prior art, while reducing the risks that the bell may uncouple from the band during the operational life of the disc brake.

[0016] It is a further object of the present invention to provide solutions for the connection between the braking band and the bell of a disc brake which may be used to obtain a radially-fed floating disc, in which a floating of the braking band with respect to the bell of a brake disc is ensured without compromising the fluid dynamics of the disc, while ensuring a stable connection between the components at the same time.

[0017] The aforesaid and other objects and advantages are achieved, according to the following aspects of the invention:

[0018] - a disc for disc brake, especially for automotive use, having the features defined in claim 1;

[0019] - a method for making a disc for disc brake, especially for automotive use, having the features defined in claim 8 or 9; and

[0020] - a mounting kit for a disc for disc brake, having the features defined in claim 10. Preferred embodiments of the invention are defined in the dependent claims, the contents of which are intended to form an integral part of this description.

[0021] Brief description of the drawings

[0022] The functional and structural features of some preferred embodiments of a disc for disc brake, a method for making a disc for disc brake and a mounting kit for a disc for disc brake according to the invention will now be described. Reference is made to the accompanying drawings, in which:

[0023] - Figure 1 shows a perspective view of an embodiment of a disc for disc brake according to the invention;

[0024] - Figure 2 shows a perspective sectional view of the disc of Figure 1, observed from the cutting plane A;

[0025] - Figure 3 shows a sectional view of the disc of Figure 1, observed from the cutting plane A, in a condition in which the bushing has not yet been deformed;

[0026] - Figure 4 shows a further sectional view of the disc of Figure 1, observed from the cutting plane A, in a condition in which the bushing has undergone plastic deformation.

[0027] Detailed description

[0028] Before explaining a plurality of embodiments of the invention in detail, it is worth noting that the application of the invention is not limited to the constructive details and to the configuration of the components presented in the following description or shown in the drawings. The invention may assume other embodiments and may be implemented or made in practice in different manners. It should also be understood that the phraseology and terminology serve a descriptive purpose and should not be understood as limiting. The use of “include” and “comprise” and variations thereof shall be understood as covering the elements set out below and the equivalents thereof, as well as additional elements and equivalents thereof.

[0029] With reference, initially, to Figure 1, a first embodiment of a disc for disc brake, in particular for automotive use, having a central axis of rotation x is described hereafter.

[0030] Furthermore, throughout this description and in the claims, terms and expressions indicating positions and orientations, such as "longitudinal," "transverse," "vertical," or "horizontal," are to be referred to the axis of rotation x, unless otherwise noted.

[0031] As shown in Figure 1 and in detail in Figure 2, for example, the disc for disc brake comprises a braking band 200 intended to be engaged by a disc brake caliper to generate braking torque. The braking band 200 has an inner annular surface 202.

[0032] The disc for brake disc further comprises a bell 204 intended to be connected to a wheel hub and comprising an annular bell wall 206 extending coaxially to the central axis x of rotation.

[0033] The annular bell wall 206 is arranged radially inside the inner annular surface 202 of the braking band 200 so as to define a gap 208 therebetween.

[0034] Furthermore, the disc for disc brake comprises a system for the radial connection of the bell 204 to the braking band 200.

[0035] The connection system comprises at least one through-hole 210 made in the annular bell wall 206, at least one band seat 212 made in the inner annular surface 202 of the braking band 200, facing toward said through-hole 210, and at least one pin 214.

[0036] The at least one pin is at least partially inserted into the band seat 212 through the through- hole 210 of the bell wall 206 in a substantially radial direction with respect to said central axis of rotation x, to bind the braking band 200 in rotation with the bell 204.

[0037] Furthermore, the connection system comprises a bushing 216 (also called a bush) fitted onto a lateral surface of the pin and arranged through said through-hole 210.

[0038] At an end facing the inner annular surface 202 of the braking band 200, the bushing 216 has a flange 218 protruding from the hole 210 extending at least partially into the gap 208 between the annular bell wall 206 and the inner annular surface 202 of the braking band 200, overlapping an edge 220 of the through-hole.

[0039] The bushing 216 further comprises an annular region 222 for grasping the pin.

[0040] The flange 218 and the annular region 222 for grasping the pin are adapted to retain the pin 214 in a condition permanently coupled to the bell 204.

[0041] Preferably, the flange 218 may be obtained by plastic deformation of the bushing 216 against the inner annular surface 202 of the braking band 200 resulting from the introduction of the pin 214 through the through-hole 210 and into the band seat 212.

[0042] Preferably, as it may, for example, be observed in detail in Figure 4, the annular region 222 for grasping the pin of the bushing 216 may be adapted to engage in an undercut region 223 of the lateral surface of the pin.

[0043] In other words, the lateral surface of the pin may have two portions having diameters DO, DI which are different from each other, so as to form the undercut region 223 in the pin.

[0044] Preferably, the pin 214 may have an end comprising an abutment formation 224 of the pin extending radially from the lateral surface of said pin and adapted to abut against an inner surface of the annular wall 206 of the bell 204. For example, the abutment formation 224 may extend away with respect to a longitudinal axis of the pin.

[0045] In this case, the portion of the lateral surface of the pin close to the abutment formation may have the diameter DO, smaller than the diameter DI of the portion of the lateral surface of the pin, distal with respect to the abutment formation.

[0046] Preferably, the annular region 222 for grasping the pin may be formed by means of a compressive force radially applied on a lateral wall of said bushing 216, after it has been fitted onto the pin before the insertion of the pin and bushing assembly into the through-hole 210 of the bell wall 206. Alternatively, the annular region 222 for grasping the pin may be formed by axial compression of said bushing 216 against the inner annular surface 202 of the braking band 200 and / or the lateral surface of the pin.

[0047] Preferably, the bushing 216 may have a cylindrical wall having a reduced thickness at said end facing the inner annular surface 202 of the braking band 200. The reduced thickness may be observed, for example, in Figure 3 and Figure 4, which show two sectional views of the disc of Figure 1, observed from the cutting plane A, in a first condition in which the bushing has not yet been deformed and in a second condition in which the bushing has undergone plastic deformation.

[0048] As it can be seen, for example, in Figures 2 and 4, the band seat 212 made in the inner annular surface 202 may have a depth in the radial direction greater than the length of a portion of the side wall of the pin intended to be accommodated in such band seat 212.

[0049] In other words, once the pin 214 is inserted at least partially into the band seat 212 through the through-hole 210 of the bell wall 206 and is retained in the through-hole 210 and the band seat 212 by the deformed bushing, an air region 226, or void, will be inside the band seat, between one end of the pin distal to the abutting formation and a back wall of the band seat. Such air region will be arranged to further accommodate the pin 314 in the event of radial stresses experienced by the bell or by the braking band.

[0050] Furthermore, as it may be observed in detail in Figures 3 and 4, the diameter DI of the lateral surface portion of the pin, distal with respect to the abutment formation, may be smaller than the diameter D2 of the band seat 212 (e.g., so as to create a clearance between the two elements), so as to allow the pin to slide in the seat band, in the presence of radial stresses and / or vibrations.

[0051] Preferably, as shown in Figure 1, the radial bell connection system may comprise a plurality of through-holes, band seats, pins, bushings (and a plurality of the other elements comprised in the radial connection system described above), arranged spaced angularly apart in said annular bell wall 206. Preferably, the bushing 216 may be made of a material comprising steel and / or aluminum. For example, the material used to make the bushing 216 is the same as that used to make the bell 204.

[0052] Preferably, the pin 214 may be made of a material comprising steel.

[0053] In a further aspect, the present invention also relates to a method for making a disc for disc brake, especially for automotive use, having a central axis of rotation x. The disc for disc brake comprises a braking band 200 intended to be engaged by a disc brake caliper to generate a braking torque, which has an inner annular surface 202. The disc for disc brake further comprises a bell 204 intended to be connected to a wheel hub and comprising an annular bell wall 206 extending coaxially to said central axis of rotation x. The annular bell wall 206 is arranged radially inside the inner annular surface 202 of the braking band 200 so as to define a gap 208 therebetween.

[0054] Furthermore, the disc for disc brake comprises a system for the radial connection of the bell to the braking band. Such connection system comprises at least one through-hole 210 made in said annular bell wall 204, at least one band seat 212 made in said inner annular surface 202 of the braking band 200, facing toward said through-hole 210, and at least one pin 214. The pin 214 is at least partially inserted into the band seat 212 through the through-hole 210 of the bell wall 206 in a substantially radial direction with respect to said central axis of rotation x, to bind the braking band 200 in rotation with the bell 204.

[0055] In one embodiment, the method comprises the following steps:

[0056] - fitting a bushing 216 on a lateral surface of the pin;

[0057] - advancing the pin 214 and the bushing 216 through said through-hole 210 until the bushing 216 abuts against the inner annular surface 202 of the braking band 200;

[0058] - further advancing the pin 214 within the band seat 212 with consequent plastic deformation of the bushing 216 at an end facing the inner annular surface 202 of the braking band 200 so as to form a flange 218 protruding from said through-hole 210 and extending at least partially into the gap 208 between the annular bell wall 206 and the inner annular surface 202 of the braking band 200 overlapping an edge 220 of the through -hole 210 and an annular formation 222 for grasping the pin, which are adapted to retain said pin 214 in a condition permanently coupled to the bell 204.

[0059] In Figure 3 it is possible to observe the situation in which the bushing 216 has been fitted onto a lateral surface of the pin but it has not yet been deformed.

[0060] In Figure 4, it is instead possible to observe in detail the situation in which the bushing 216 has been plastically deformed at one end facing the inner annular surface 202 of the braking band 200, so as to form the flange 218 and the annular formation 222 for grasping the pin.

[0061] In an alternative embodiment, the method comprises the following steps:

[0062] - fitting a bushing 216 on a lateral surface of the pin;

[0063] - radially compressing a lateral surface of the bushing 216 to form an annular region 222 for grasping the pin;

[0064] - advancing the pin 214 and the bushing 216 through said through-hole 210 until the bushing 216 abuts against the inner annular surface 202 of the braking band 200;

[0065] - further advancing the pin 214 within the band seat 212 resulting in plastic deformation of the bushing 216 at an end facing the inner annular surface 202 of the braking band 200 so as to form a flange 218 protruding from said through-hole 210 and extending at least partially into the gap 208 between the annular bell wall 206 and the inner annular surface 202 of the braking band 200 overlapping an edge 220 of the through-hole 210.

[0066] The flange 218 and the annular region 222 for grasping the pin are adapted to retain the pin 214 in a condition permanently coupled to the bell 204.

[0067] In a still further aspect, the present invention relates to a mounting kit for a disc for disc brake.

[0068] In one embodiment, the mounting kit comprises:

[0069] - a braking band 200 intended to be engaged by a caliper of a brake disc to generate braking torque, which has an inner annular surface 202 in which at least one band seat 212 is made; - a bell 204 intended to be connected to a wheel hub and comprising an annular bell wall 206 in which at least one through-hole 210 is made;

[0070] - at least one pin 214 which may be inserted into the band seat 212 through the through-hole 210 of the bell wall 206 to bind the braking band 200 in rotation with the bell 204; and

[0071] - a bushing 216 adapted to be fitted on a lateral surface of said pin 214 and arranged through said through-hole 210, at least partially plastically deformable at one end thereof.

[0072] Preferably, the bushing may be deformable on the entire lateral surface which will adhere to the lateral surface of the pin during deformation.

[0073] All the embodiments described above for the disc for disc brake, which relate to the elements comprised in the mounting kit, although not repeated here, may clearly find similar application for the elements of the mounting kit.

[0074] The advantage achieved is therefore that of having provided solutions that:

[0075] - reduce the manufacturing and assembly complexity of the disc brake with respect to the prior art, while reducing the risks that the bell may uncouple from the band during the operational life of the disc brake at the same time;

[0076] - may be used to obtain a radially-fed floating disc, in which floating of the braking band with respect to the bell of a brake disc is ensured without compromising the fluid dynamics of the disc, while ensuring a stable connection between the components at the same time.

[0077] Various aspects and embodiments of a disc for disc brake, a method for making a disc for disc brake, and a mounting kit for a disc for disc brake according to the invention have been described. It is understood that each embodiment may be combined with any other embodiment. Furthermore, the invention is not limited to the described embodiments but may be varied within the scope defined by the accompanying claims.

Claims

CLAIMS1. A disc for disc brake, particularly for automotive use, having a central axis of rotation (x), comprising:- a braking band (200) intended to be engaged by a caliper of the brake disc to generate braking torque, which has an inner annular surface (202);- a bell (204) intended to be connected to a wheel hub and comprising an annular bell wall (206) extending coaxially to said central axis (x) of rotation, wherein said annular bell wall (206) is arranged radially inside the inner annular surface (202) of the braking band (200) so as to define a gap (208) therebetween, and- a system for the radial connection of the bell (204) to the braking band (200), comprising at least one through-hole (210) made in said annular bell wall (206); at least one band seat (212) made in said inner annular surface (202) of the braking band (200), facing said through-hole (210); at least one pin (214) at least partially inserted into the band seat (212) through the through-hole (210) of the bell wall (206) in a substantially radial direction with respect to said central axis of rotation (x), to bind the braking band (200) in rotation with the bell (204), characterized in that the connection system further comprises a bushing (216) fitted on a lateral surface of the pin (214) and arranged through said through-hole (210), which has, at an end facing the inner annular surface (202) of the braking band (200), a flange (218) protruding from said hole (210) which at least partially extends into the gap (208) between the annular bell wall (206) and the inner annular surface (202) of the braking band (200) overlapping an edge (220) of the through-hole, and an annular region (222) for grasping the pin, which are adapted to retain said pin (214) in a condition permanently coupled to the bell (204).

2. A disc according to claim 1, wherein said flange (218) is obtained by plastic deformation of the bushing (216) against the inner annular surface (202) of the braking band (200) resulting from the introduction of the pin (214) through the through-hole (210) and into the band seat (212).

3. A disc according to claim 1, wherein said annular region (222) for grasping the pin is adapted to engage an undercut region of the lateral surface of the pin.

4. A disc according to claim 3, wherein said annular region (222) for grasping the pin is formed by radial compression of a lateral wall of said bushing (216) against said undercut region.

5. A disc according to claim 3, wherein said annular region (222) for grasping the pin is formed by axial compression of said bushing (216) against the inner annular surface (202) of the braking band (200).

6. A disc according to any one of the preceding claims, wherein said bushing (216) has a cylindrical wall having a reduced thickness at said end facing the inner annular surface (202) of the braking band (200).

7. A disc according to any one of the preceding claims, wherein the pin (214) has an end comprising an abutting formation (224) of the pin extending radially from the lateral surface of said pin and adapted to abut against an inner surface of the annular wall (206) of the bell (204).

8. A method for making a disc for disc brake, particularly for automotive use, having a central axis of rotation (x), comprising:- a braking band (200) intended to be engaged by a caliper of the brake disc to generate braking torque, which has an inner annular surface (202);- a bell (204) intended to be connected to a wheel hub and comprising an annular bell wall (206) extending coaxially to said central axis of rotation (x), wherein said annular bell wall (206) is arranged radially inside the inner annular surface (202) of the braking band (200) so as to define a gap (208) therebetween, and- a system for the radial connection of the bell to the braking band, comprising at least one through-hole (210) made in said annular bell wall (204); at least one band seat (212) made in said inner annular surface (202) of the brakingband (200), facing said through-hole (210); at least one pin (214) at least partially inserted into the band seat (212) through the through-hole (210) of the bell wall (206) in a substantially radial direction with respect to said central axis of rotation (x), to bind the braking band (200) in rotation with the bell (204), the method being characterized in that it comprises the following steps: fitting a bushing (216) on a lateral surface of the pin; advancing the pin (214) and the bushing (216) through said through-hole (210) until the bushing (216) abuts against the inner annular surface (202) of the braking band (200); further advancing the pin (214) within the band seat (212) with consequent plastic deformation of the bushing (216) at an end facing the inner annular surface (202) of the braking band (200) so as to form a flange (218) protruding from said through-hole (210) and extending at least partially into the gap (208) between the annular bell wall (206) and the inner annular surface (202) of the braking band (200) overlapping an edge (220) of the through-hole (210) and an annular region (222) for grasping the pin, which are adapted to retain said pin (214) in a condition permanently coupled to the bell (204).

9. A method for making a disc for disc brake, particularly for automotive use, having a central axis of rotation (x), comprising:- a braking band (200) intended to be engaged by a caliper of the brake disc to generate braking torque, which has an inner annular surface (202);- a bell (204) intended to be connected to a wheel hub and comprising an annular bell wall (206) extending coaxially to said central axis of rotation (x), wherein said annular bell wall (206) is arranged radially inside the inner annular surface (202) of the braking band (200) so as to define a gap (208) therebetween, and- a system for the radial connection of the bell to the braking band, comprising at least one through-hole (210) made in said annular bell wall (204); at least one band seat (212) made in said inner annular surface (202) of the braking band (200), facing said through-hole (210); at least one pin (214) at least partially inserted into the band seat (212) through the through-hole (210) of the bell wall (206) in a substantially radial direction with respect to said central axis of rotation (x), to bind the braking band (200) in rotation with the bell (204),the method being characterized in that it comprises the following steps: fitting a bushing (216) on a lateral surface of the pin; radially compressing a lateral surface of said bushing (216) to form an annular region (222) for grasping the pin; advancing the pin (214) and the bushing (216) through said through-hole (210) until the bushing (216) abuts against the inner annular surface (202) of the braking band (200); further advancing the pin (214) within the band seat (212) resulting in plastic deformation of the bushing (216) at an end facing the inner annular surface (202) of the braking band (200) so as to form a flange (218) protruding from said through-hole (210) and extending at least partially into the gap (208) between the annular bell wall (206) and the inner annular surface (202) of the braking band (200) overlapping an edge (220) of the through-hole (210), said flange (218) and said annular region (222) for grasping the pin being adapted to retain said pin (214) in a condition permanently coupled to the bell (204).

10. A mounting kit for a disc for disc brake, comprising:- a braking band (200) intended to be engaged by a caliper of a brake disc to generate braking torque, which has an inner annular surface (202) in which at least one band seat (212) is made;- a bell (204) intended to be connected to a wheel hub and comprising an annular bell wall (206) in which at least one through-hole (210) is made;- at least one pin (214) insertable into the band seat (212) through the through-hole (210) of the bell wall (206) to bind the braking band (200) in rotation with the bell (204); and- a bushing (216) adapted to be fitted on a lateral surface of said pin (214) and arranged through said through-hole (210), at least partially plastically deformable at one end thereof.

Images