Brake pad

Abstract

A brake pad for a disc braking system comprising a caliper and a disc comprises a tribologically active friction member (2), a support (3) of the friction member (2) coupled to the friction member (2) and intended, in use, for assembling the brake pad in the caliper, an anchoring system for anchoring the friction member (2) to the support (3); the anchoring system comprises a net (5), associated with the support, and a plurality of nails (7a, 7b), welded to the support (3), that are incorporated into the friction member (2).

Description

[0001] DESCRIPTION

[0002] BRAKE PAD

[0003] Technical field

[0004] The present invention relates to a brake pad and in particular, a brake pad for disc brakes intended for competitions.

[0005] Background art

[0006] Brake pads for disc brakes usually comprise a generally metallic support, on which a friction member is fixed, preferably by means of adhesive or glue.

[0007] The support is housed in the brake caliper and is subjected to the action of the pistons thereof, while the friction member is intended to act on the disc of the braking system.

[0008] Brake pads, in particular, competition brake pads, are usually required to be immediately effective when new to instantly exploit the maximum braking potential, uniformly decreasing during use to allow the use thereof up to a few millimeters from the support, constant performance, reduced or no bedding-in and reduced risk of pad fractures, which may be caused due to the presence of air or gas bubbles in the friction member.

[0009] Also to give the pads the aforesaid features, numerous and different production processes have been developed over time to transform a brake friction composition, referred to as compound, into the friction member so as to optimize the performance of the pads.

[0010] A drawback of known brake pads derives from the fact that such processes may comprise thermal cycles, which mitigate or cancel out the effect of any glue or adhesive, with serious safety risks in the event of the friction member detaching from the metal support.

[0011] Therefore, in the field of disc brakes, the need is felt for brake pads with an extremely reliable anchoring system for anchoring the friction member to the support. In this context, it is intended to propose a brake pad capable of overcoming at least the drawback of the aforementioned background art, and meeting the aforesaid need.

[0012] Object of the invention

[0013] In particular, it is the object of the present invention to provide a brake pad, in which the friction member is joined to the support in a highly efficient manner.

[0014] Such object is achieved by a brake pad comprising the technical features set out in one or more of the appended claims. The dependent claims correspond to possible different embodiments of the invention.

[0015] According to an aspect, the present invention relates to a brake pad for a disc braking system comprising a caliper and a disc.

[0016] The brake pad comprises a tribologically active friction member and a support of the friction member coupled to the friction member and intended for assembling the brake pad in the caliper.

[0017] The brake pad is preferably adhesive-free and obtained with a production process comprising a pressing step and a heating step for a mixture of powders.

[0018] The brake pad comprises an anchoring system for anchoring the friction member to the support. The anchoring system comprises a net associated with the support and a plurality of nails welded to the support.

[0019] The nails extend into the friction member and, together with the net, are incorporated into the friction member during the production process of the brake pad.

[0020] Advantageously, since the net and the nails are secured to the support and incorporated into the friction member, they ensure a solid anchoring of the friction member to the support, in particular, also in the absence of adhesive that could degrade or become degraded during the brake pad production process. The anchoring system ensures the correct anchoring of the friction member in operating conditions, in particular, the speed of the disc and braking action of the friction member on the disc.

[0021] The net is preferably welded to the support for maximum bonding of the net to the support, so as to obtain a mechanical connection of the net to the support.

[0022] The net is preferably an expanded metal net, preferably having a rhomboidal or round mesh.

[0023] Advantageously, the Applicant has observed that, given the “saw-toothed” section, the expanded metal net satisfactorily withstands the pressing step without being completely flattened, ensuring excellent anchoring of the friction member to the support.

[0024] The expanded metal net is preferably made from a sheet having a thickness comprised between 1 .2 mm and 1 .8 mm.

[0025] The expanded metal net preferably has an overall height comprised between 1 .4 mm and 2 mm.

[0026] The Applicant has observed that an expanded metal net obtained from a sheet with these thicknesses ensures excellent anchoring once the brake pad has been pressed, while maintaining a safe thickness when the friction member has worn out with use, making it unlikely to interfere with the disc. The expanded net may be flattened or not, based on the desired precision of the final thickness of the net.

[0027] The net preferably has a theoretical vacuum comprised between 55% and 69%, and, even more preferably, it has a theoretical vacuum equal to 62%. Thereby, advantageously, the mixture of powders fills a volume sufficient to maximize the anchoring of the friction member to the support.

[0028] The net preferably comprises a plurality of first openings, each at a respective nail. Openings in the net shall be understood as portions of the net, in which the net is interrupted or cut. Thereby, advantageously, since there is no interference between the net and the nails, it is possible to optimize the adhesion of the net to the support. The support preferably comprises at least one through hole, to facilitate an outflow of the gases present in the mixture of powders or that form during the pressing and / or heating thereof.

[0029] The net preferably has an opening at the through hole in the support so as not to interfere with the aforementioned outflow of any gases. Openings in the net shall be understood as portions of the net, in which the net is interrupted or cut.

[0030] The plurality of nails preferably comprises at least one first nail of a first height, and at least a second nail of a second height, smaller than the first height.

[0031] The nails of a smaller height are preferably arranged toward a periphery of the support.

[0032] Advantageously, in the periphery of the support, or, in general, in some parts of the brake pad, there may be less material of the friction member surrounding the nails. The Applicant has observed that using nails of smaller height reduces the risk of cracks in the friction member at such nails, if they are surrounded by less material with respect to other nails in the brake pad. The nails of the plurality of nails are preferably knurled nails to increase, for example, with respect to a smooth nail, an adhesion of the mixture of powders and the friction member to the nails.

[0033] The brake pad preferably has a ratio between an area, expressed in mm2, of a surface of the friction member acting on the disc and the nails of the plurality of nails that is comprised between 800 and 1700, preferably comprised between 1000 and 1500.

[0034] The brake pad preferably has a ratio between a height, expressed in mm, of the friction member measured from the support comprised between 2 and 4, preferably comprised between 2.5 and 3.5.

[0035] The distribution and height of the nails in the brake pad are optimized to ensure the best anchoring of the friction member and therefore, the reliability of the brake pad without The nails of the plurality of nails are preferably symmetrically arranged with respect to a plane orthogonal to a prevalent direction of development of the brake pad.

[0036] Further features and advantages of the aforesaid aspects will be more apparent from the indicative and therefore non-limiting description of a preferred, but non-exclusive, embodiment of a brake pad for a disc braking system.

[0037] Brief description of the drawings

[0038] This description will be presented below with reference to the appended drawings, provided purely for indicative and therefore, non-limiting purposes, in which:

[0039] - figure 1 shows a diagrammatic front view of a brake pad according to the description;

[0040] - figure 2 shows a diagrammatic sectional view of the brake pad in figure 1 ;

[0041] - figure 3 shows a diagrammatic front view of a semi-finished product forming part of the brake pad in figure 1 ;

[0042] - figure 4 shows a diagrammatic side view of the semi-finished product in figure 3;

[0043] - figure 5 shows a diagrammatic front view of a detail of a component of the brake pad in figure 1 .

[0044] Detailed description of preferred embodiments of the invention

[0045] With reference to figures 1 and 2, a brake pad is globally denoted by reference numeral 1 according to the description.

[0046] The brake pad 1 is intended for a disc braking system, not shown, comprising a caliper and a disc, in which the brake pad 1 , actuated by the caliper, acts on the disc.

[0047] The brake pad 1 comprises a friction member 2, in use, tribologically active on the disc, and a support 3 of the friction member 2. The pad 1 has a direction of development D, which, in the illustrated example, corresponds to the prevalent direction of development to which explicit reference will be made without loss of generality.

[0048] The friction member 2 is coupled to the support 3, which is intended for assembling the brake pad 1 in the caliper.

[0049] In a preferred embodiment, the brake pad 1 is preferably adhesive-free and preferably made with a production process comprising a pressing step and a heating step for a mixture of powders.

[0050] The pressure to which the mixture of powders is subjected may be in the order of 2000 Kg / cm2.

[0051] In the illustrated example, the support 3 comprises three through holes 4, to facilitate an outflow of the gases present in the mixture of powders, or that form during the pressing and / or heating thereof.

[0052] In alternative and not shown embodiments, the support 3 has any number of holes 4 based, for example, on process requirements.

[0053] The brake pad 1 comprises an anchoring system for anchoring the friction member 2 to the support 3. The anchoring system comprises a net 5 associated with, preferably welded to, the support 3.

[0054] The net 5 is an expanded metal net, preferably having a rhomboidal or round mesh.

[0055] In a preferred embodiment, the expanded metal net is made from a metal sheet having a thickness S comprised between 1 .2 mm and 1 .8 mm.

[0056] The expanded metal net preferably has an overall height, or total thickness, H5, comprised between 1 .3 mm and 2 mm

[0057] The net 5 may be of the substantially known flattened type.

[0058] The net 5 has a theoretical vacuum comprised between 55% and 69%, and preferably a theoretical vacuum equal to 62%.

[0059] In the illustrated example, the net 5 has a long diagonal DL having a size comprised between 8 mm and 12 mm, a short diagonal DC having a size comprised between 6 mm and 9 mm, and advancement AV comprised between 1 .2 mm and 1 .6 mm. The net 5 is welded to the support with the short diagonal DC parallel to the direction D.

[0060] The net 5 has openings 6 at the holes 4 in the support 3.

[0061] The anchoring system anchoring the friction member 2 to the support 3 comprises a plurality of nails 7a, 7b welded to the support 3.

[0062] The nails 7a, 7b are preferably made of a soft material, e.g., brass, so as not to damage the disc in the event of the friction member wearing up to the nails 7a, 7b.

[0063] As shown, the nails 7a have a height H7a smaller than a height H7b of the nails 7b.

[0064] The nails 7a of smaller height are arranged toward a periphery of the support 3, for example, at opposite ends of the friction member 2 along the prevalent direction of development D of the brake pad 1 and / or close to edges of the friction member 2, which enter the plane of the figure as shown in figure 1 .

[0065] As shown, in particular, in figure 2, the nails 7a, 7b extend into the friction member 2 and, together with the net 5 are incorporated into the friction member 2.

[0066] In particular, the nails 7a, 7b and the net 5 are welded to the support 3, obtaining a semi-finished product 10 of the type shown in figure 10, and subsequently incorporated into the friction member 2 during the production process for the brake pad 1 , when the mixture of powders is pressed onto the support 3.

[0067] The net 5 preferably has a plurality of openings 8, each at a respective nail 7a, 7b.

[0068] In the embodiment, shown by way of example, the nails 7a, 7b are knurled for better adhesion of the friction member 2 to the nails 7a, 7b.

[0069] In the embodiment shown as example, the nails 7a, 7b are symmetrically arranged with respect to a plane P orthogonal to the prevalent direction of development D. In alternative, non-illustrated embodiments, the nails 7a, 7b may all be the same height, they may not be knurled, and may be asymmetrically arranged on the support 3.

[0070] The brake pad 1 has a ratio between an area A, expressed in mm2, of a surface of the friction member 2 acting on the disc and the number of the nails 7a, 7b of the plurality of nails comprised between 800 and 1700, preferably between 1000 and 1500.

[0071] The brake pad 1 preferably has a ratio between a height H2, expressed in mm, of the friction member 2 measured from the support 3, and the height of the nails 7a, 7b of the nails 7a, 7b comprised between 2 and 4, preferably between 2.5 and 3.5.

Claims

CLAIMS1 . A brake pad for a disc braking system comprising a caliper and a disc, said brake pad comprising a tribologically active friction member (2); a support (3) of the friction member (2) coupled to the friction member (2) and intended, in use, for assembly of the brake pad in the caliper; an anchoring system for anchoring the friction member (2) to the support (3), said anchoring system comprising a net (5) associated with the support and a plurality of nails (7a, 7b) welded to the support (3) and extending into the friction member (2), said net (5) and said nails (7a, 7b) being incorporated into the friction member (2).

2. A brake pad according to claim 1 wherein said net (5) is welded to the support (3).

3. A brake pad according to claim 1 or 2, wherein said net (5) is an expanded metal net, preferably having a rhomboidal or round mesh.

4. A brake pad according to claim 3, wherein said expanded metal net is made from a sheet having a thickness of between 1 .2 mm and 1 .8 mm.

5. A brake pad according to any one of the preceding claims, wherein said net (5) has a theoretical vacuum of between 55% and 69%, said net preferably having a theoretical vacuum equal to 62%.

6. A brake pad according to any one of the preceding claims, wherein said net (5) has a plurality of first openings (8), each first opening (8) of the plurality of first openings being at a corresponding nail (7a, 7b) of said plurality of nails.

7. A brake pad according to any one of the preceding claims, wherein said support (3) has at least one through hole (4), said net (5) having a second opening (6) at said through hole (4).

8. A brake pad according to any one of the preceding claims, wherein said plurality of nails comprises at least a first nail of a first height and at least a second nail of a second height lower than the first height.

9. A brake pad according to claim 8, wherein said second nail is arranged towards a periphery of the friction member (2).

10. A brake pad according to any one of the preceding claims, wherein said plurality of nails (7a, 7b) comprises at least one knurled nail.1 1 . A brake pad according to any one of the preceding claims, having a ratio between an area (A), expressed in mm2, of a surface of the friction member (2) acting on the disc and the number of nails of the plurality of nails of between 800 and 1700, preferably between 1000 and 1500.

12. A brake pad according to any one of the preceding claims, having a ratio between a height (H2), expressed in mm, of the friction member (2) measured from the support (3) and a height of the nails (7a, 7b) of said plurality of nails (7a, 7b) of between 2 and 4, preferably between 2.5 and 3.5.

13. A brake pad according to any one of the preceding claims, wherein the nails (7a, 7b) of the plurality of nails (7a, 7b) are arranged symmetrically with respect to a plane (P) orthogonal to a prevalent direction of development (D) of the brake pad.

14. A brake pad according to any one of the preceding claims, which isadhesive-free.

15. A brake pad according to any one of the preceding claims, made by a production process comprising a pressing step and a heating step for a mixture of powders, the pressing step and the heating step incorporating said net (5) and said nails (7a, 7b) in the friction member.

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