DESCRIPTION

[0001]. Field of the invention

[0002]. The present invention relates to a caliper body of disc brake, as well as to a brake caliper comprising such a caliper body, and to a method for manufacturing said caliper body.

[0003]. Background art

[0004]. As known, in a disc brake comprising a caliper body, the caliper body is generally arranged straddling the outer peripheral margin of a brake disk, adapted to rotate about a rotation axis (A- A) defining an axial direction (X-X).

[0005]. Generally, the caliper body comprises a first elongated portion and a second elongated portion connected by at least one bridge.

[0006]. Typically, the caliper body comprises a plurality of positioning references configured to be located by clamping devices or manipulation devices to position the caliper body in a predetermined position to allow machining to be performed.

[0007]. In some caliper bodies of known type, the positioning references are made as flat surfaces, or as recesses with angled surfaces, or in other cases, they are indented into the caliper body and form valleys with respect to the outer surface of the caliper body.

[0008]. Such indented positioning references, although they meet the need to create portions of the caliper body relative to which the caliper body can be oriented for subsequent machining operations, form body caliper portions in which a working liquid or water can deposit in use or during machining operations, remaining in prolonged contact with the caliper body and triggering corrosive phenomena. Document US7168529B2 shows a positioning reference made as a conical-shaped recess in the caliper body, for example.

[0009]. Furthermore, it is worth noting that in the manufacturing of caliper bodies by casting material in a mold, the forming of the portions of the caliper body comprising such positioning references as recesses may be unstable and may result in undesirable variations in mechanical and surface properties, as well as in the shape of a caliper body relative to another. Therefore, if there are variations in the tolerances of such positioning references as compared to the design, it is required to discard these caliper bodies from the subsequent machining stages.

[0010]. Therefore, there is a strong need in the industry to manufacture caliper bodies which are easily and unambiguously positionable in at least one predetermined position and have increased corrosion resistance.

[0011]. There is a further need to manufacture caliper bodies with increased dimensional stability.

[0012]. Furthermore, there is a need to manufacture a caliper body with at least one highly precise self-centering positioning reference.

[0013]. Therefore, the problem underlying the present invention is to provide a caliper body, a brake caliper and a method for manufacturing said caliper body, which have structural and functional features such as to meet the aforementioned needs while obviating the drawbacks mentioned with reference to the prior art and meet the aforesaid needs felt.

[0014]. Solution

[0015]. It is an object of the present invention to provide a caliper body having high dimensional stability and low tendency to corrosion.

[0016]. This and other objects and advantages are achieved by a caliper body according to claim 1, as well as by a brake disc according to claim 7, as well as by a method of manufacturing said caliper body according to claim 8.

[0017]. Some advantageous embodiments are the subject of the dependent claims.

[0018]. From the analysis of this solution, it has emerged how the suggested solution allows to obtain an increased resistance to corrosion compared to the known solutions, avoiding the stagnation of corrosive liquids at the positioning references to orient and fix the caliper body to be machined.

[0019]. Furthermore, the suggested solution allows to manufacture caliper bodies with improved dimensional stability compared to the known solutions having a self-centering, draining, and highly precise positioning reference.

[0020]. Furthermore, the suggested solutions allow to reduce the chip removal machining tolerances of the finished caliper body.

[0021]. Yet further, by virtue of the suggested solutions, it is possible to obtain a higher production of caliper bodies and a reduction of waste in the production processes.

[0022]. Yet further, by virtue of the suggested solutions, it is possible to avoid unstable zones in the caliper body during the forming and solidifying stages in the production process.

[0023]. Drawings

[0024]. Further features and advantages of the caliper body, brake disc, and method of manufacturing said caliper body will become apparent from the description provided below of preferred embodiments thereof, given by way of non limiting example, with reference to the accompanying drawings, in which:

[0025]. - figure 1 is an axonometric view of a caliper body with a first positioning reference and a second positioning reference as known from the prior art;

[0026]. - figure 2 is an axonometric view of a caliper body according to the invention;

[0027]. - figure 3 is a plan view of the caliper body in figure 2; [0028]. - figure 4 is an axonometric view of an enlarged detail of the caliper body in figure 2, in which a first positioning reference according to the present invention is shown, comprising at least three separate ribs arranged in a mutually circular manner;

[0029]. - figure 5 is an axonometric view of an enlarged detail of the caliper body in figure 2, showing a second positioning reference according to the present invention comprising two parallel and mirroring ribs;

[0030]. - figure 6 is an axonometric view of the first positioning reference in figure 4, which shows a section plane of first reference PI perpendicular to a first caliper body surface portion passing through a first reference rib 6 and a second channel 13 of first reference;

[0031]. - figure 7 is an axonometric view of the positioning reference in figure 5, which shows a section plane of second reference P2 perpendicular to a caliper body second surface portion passing through two second reference ribs 16, 17 and a second reference channel arranged between said second reference ribs 16, 17;;

[0032]. - figure 8 is an axonometric section view of a mold for manufacturing a caliper body according to the present invention. [0033]. Description of some preferred embodiments

[0034]. According to a general embodiment, a brake caliper 1 for a disc brake is provided.

[0035]. Said caliper body 1 is adapted to straddle an associable brake disc.

[0036]. Said brake disc comprises a first braking surface and a second braking surface, where an axial direction A-A coinciding with or parallel to the rotation axis of the disc, a radial direction R-R orthogonal to said axial direction A-A, and a tangential direction T-T orthogonal to both said axial direction A-A and said radial direction R-R are defined.

[0037]. Said caliper body 1 comprises a first elongated portion 2, adapted to face said braking surface and a second elongated portion 3 opposite to said first elongated portion 2 and adapted to face said second braking surface.

[0038]. Said caliper body 1 comprises at least one bridge 4 adapted to connect said first elongated portion 2 to said second elongated portion 3 so as to straddle the brake disc when said caliper body 1 is assembled to the brake disc.

[0039]. Said caliper body 1 comprises at least a first positioning reference 5 configured to accommodate a respective first bracketing device to position and fix said caliper body 1 so as to allow material removal machining operations.

[0040]. Said first positioning reference 5 is embossed. In other words, said first positioning reference 5 protrudes from said caliper body 1.

[0041]. Said first positioning reference 5 comprises at least one first reference rib 6, a second first reference rib 7, and a third first reference rib 8. Each of said first reference ribs 6, 7, 8 is embossed.

[0042]. Said first reference ribs 6, 7, 8 are separated from each other and arranged circularly to accommodate said first bracketing device and to prevent a liquid from accumulating between said first reference ribs 6, 7, 8.

[0043]. According to an embodiment, said first reference ribs 6, 7, 8 form a self-centering structure to accommodate said first bracketing device.

[0044]. According to an embodiment, said first positioning reference 5 when coupled to the respective first bracketing device forms an exclusively rotational constraint for said caliper body 1 and prevents translations along three mutually orthogonal directions.

[0045]. According to an embodiment, each of the first reference ribs 6, 7, 8 comprises a respective inclined surface 9, 10, 11 of first reference.

[0046]. According to an embodiment, the extensions of each inclined surface 9, 10, 11 of first reference meet at the same point.

[0047]. According to an embodiment, said inclined surfaces 9, 10, 11 of first reference are curvilinear surfaces.

[0048]. According to an embodiment, said inclined surfaces 9, 10, 11 of first reference are conical surface portions.

[0049]. According to an embodiment, said first reference ribs 6, 7, 8 define a discontinuous conical positioning surface.

[0050]. According to an embodiment, the first reference ribs 6, 7, 8 form petals arranged along a circumference. Along said circumference, the first reference ribs are each arranged at 120° from the adjacent one.

[0051]. According to an embodiment, said first positioning reference 5 comprises a plurality of first reference channels 12, 13, 14 between each first reference rib 6, 7, 8 and a first adjacent one of said first reference ribs 6, 7, 8.

[0052]. In other words, each first reference rib 6, 7, 8 is interspersed with a respective first reference channel 12, 13, 14 with respect to a first adjacent rib.

[0053]. According to an embodiment, each first reference channel 12, 13, 14 is inclined to prevent a liquid from accumulating between said first reference ribs 6, 7, 8.

[0054]. According to an embodiment, said first reference channels 12, 13, 14 cross one another in a central zone of the first positioning reference 5.

[0055]. According to an embodiment, said first reference channels 12, 13, 14 are mutually arranged at 120°.

[0056]. According to an embodiment, said caliper body 1 comprises at least a second positioning reference 15 configured to accommodate a respective second bracketing device to position and fix said caliper body 1 so as to allow chip removal machining operations. [0057]. According to an embodiment, said second positioning reference 15 is embossed, in other words, it protrudes outwards from the caliper body 1.

[0058]. According to an embodiment, said second positioning reference 15 comprises a first rib 16 of second reference and a second rib 16 of second reference.

[0059]. According to an embodiment, said second reference ribs 16, 17 are separated and parallel.

[0060]. According to an embodiment, said second reference 15 comprises a second reference channel arranged between said second reference ribs 16, 17, where said second reference channel is configured to prevent a liquid from accumulating between said second reference ribs 16, 17

[0061]. According to an embodiment, said second reference ribs 16, 17 define a substantially V-shaped positioning surface. [0062]. According to an embodiment, each second reference rib 16, 17 comprises a respective inclined surface 21, 22 of second reference, or first inclined surface 21 of second reference and second inclined surface of second reference.

[0063]. According to an embodiment, the extensions of each inclined surface 21, 22 of second reference in the direction of said caliper body 1 meet in the same straight line.

[0064]. According to an embodiment, said inclined surfaces 21, 22 of second reference are flat.

[0065]. According to an embodiment, said first positioning reference 5 and said second positioning reference 15 protrude from respective caliper body surface portions 18, 19, where said caliper body surface portions 18, 19 are coplanar.

[0066]. According to an embodiment, said first positioning reference 5 protrudes from said first elongated portion 2.

[0067]. According to an embodiment, said second positioning reference 15 protrudes from said first elongated portion 2.

[0068]. According to a first embodiment, said first elongated portion 2 defines at least one cylinder 20 to accommodate thrust means which bias a brake pad.

[0069]. According to an embodiment, said caliper body 1 is obtained by sand-casting a molten metal.

[0070]. According to an embodiment, said first positioning reference 5 is obtained by sand-casting a molten metal.

[0071]. According to an embodiment, said second positioning reference 15 is obtained by sand-casting a molten metal. [0072]. According to an embodiment, said caliper body 1 is a caliper body of floating caliper.

[0073]. According to an alternative embodiment, said caliper body l is a semi-finished cast product.

[0074]. The present invention further relates to a brake caliper comprising a caliper body 1 as described above.

[0075]. The present invention further relates to a method for manufacturing a caliper body 1 as described above.

[0076]. Preferred or advantageous variants of such a method may comprise any step which can be inferred, even only implicitly, from the above description of the caliper body.

[0077]. Said method comprises the following steps: a- providing a casting mold 23 comprising at least two half molds 24, 25; b- making, in said mold 23, at least three recesses 26, 27, 28 adapted to form said first positioning reference 5 comprising said first rib 6 of first reference, said second rib 7 of first reference, and said third rib 8 of first reference; c- casting a molten material into the mold 23; d- removing the caliper body 1 comprising at least said first positioning reference 5 from the mold 23.

[0078]. According to a possible operation mode, said method comprises the following steps: e- positioning said caliper body 1 on the equipment of a CNC working machine in at least one predetermined position by means of at least said first positioning reference 5, f- fixing said caliper body 1 in said at least one predetermined position on said equipment, g- performing at least one material removal machining operation on said caliper body 1.

[0079]. According to a possible operation mode, said method comprises the step of making, at the same time as step b-, in said casting mold 23, two further recesses 29, 30 adapted to form said second positioning reference 15 comprising said first rib 16 of second reference and said second rib 17 of second reference.

[0080]. According to a possible operation mode, said method comprises, before said step e-, the step of handling said caliper body 1 by gripping it at least at said first positioning reference 5.

[0081]. According to an embodiment, said casting mold 23 is made of sand.

[0082]. According to an embodiment, said caliper body 1 is positioned and/or fixed in said at least one predetermined position by at least said first and said second positioning references 5, 15. [0083]. In order meet specific needs, those skilled in the art could make variations to the embodiments of the aforesaid caliper body, brake caliper, and method of the present invention or could replace elements with others which are functionally equivalent. LIST OF REFERENCE SIGNS

1 caliper body

2 first elongated portion

3 second elongated portion

4 bridge

5 first positioning reference

6 first rib of first reference

7 second rib of first reference

8 third rib of first reference

9 first inclined surface of first reference

10 second inclined surface of first reference

11 third inclined surface of first reference

12 first channel of first reference

13 second channel of first reference

14 third channel of first reference

15 second positioning reference

16 first rib of second reference

17 second rib of second reference

18 first caliper body surface portion

19 caliper body second surface portion

20 cylinder

21 first inclined surface of second reference

22 second inclined surface of second reference

23 mold

24 first half-mold

25 second half-mold

26 first mold recess

27 second mold recess

28 third mold recess

29 fourth mold recess

30 fifth mold recess

Pi first reference section plan

P2 second reference section plan B-B direction and orientation of first reference section view D-D direction and orientation of second reference section view A-A axial direction R-R radial direction C-C tangential direction