Patent ID: 12209625

DESCRIPTION OF SOME PREFERRED EMBODIMENTS

According to a general embodiment, a brake caliper1for a disc brake2is provided.

In a disc brake2an axial direction X-X is defined either coinciding with or parallel to the rotation axis A-A- of the disc3of the disc brake2, a radial direction R-R orthogonal to the axial direction X-X, and a tangential direction T-T, orthogonal to both the axial direction X-X and to the radial direction R-R.

Said brake caliper1comprises a caliper body4, adapted to straddle the disc3.

Said caliper body4comprises a first elongated portion5adapted to face a first braking surface6of the disc3, and a second elongated portion7, opposite to said first elongated portion5and adapted to face a second braking surface8of the disc3opposed to said first braking surface6.

Said caliper body4further comprises at least one bridge9to connect said first elongated portion5and said second elongated portion7to each other arranged straddling the disc3.

Said brake caliper1further comprises at least one pair of opposite brake pads10,20, comprising a first brake pad10and a second brake pad20.

Each brake pad10,20of said at least one pair of opposite brake pads10,20comprises friction material11,21, and a support plate12,22, which supports said friction material11,21. Said support plate12,22of each brake pad10,20comprises a plate back13,23facing a respective elongated portion5or7of said elongated portions5,7of the caliper body4.

In this manner, said first brake pad10comprises first friction material11and a first support plate12comprising a first plate back13and said second brake pad20comprises second friction material21and a second support plate22comprising a second plate back23.

Said brake caliper1further comprises at least one thrust device14comprising an actuator16, adapted to apply a thrust action on said plate back13to abut said first brake pad10of said pair of brake pads10,20against a braking surface6of said facing braking surfaces6,8of the disc3. According to an embodiment, said thrust device14comprises at least one piston44, adapted to press against the plate back13of the first brake pad10.

According to an embodiment, said actuator16comprises a ball screw assembly designed to apply an axial thrust action on a piston44to push said first brake pad10axially to make it abut it against a facing braking surface6of the disc3.

According to an embodiment, said caliper body4further comprises at least one housing adapted to receive at least one portion of said at least one thrust device14. According to an embodiment, said at least one housing of the caliper body4comprises a housing bottom wall18facing in the axial direction X-X, and at least one housing edge19, facing said back plate13of the first one brake pad10. According to an embodiment, said piston44is associated with a seal45to prevent the infiltration of water or foreign bodies, such as dust or gravel, into the actuator.

Said brake caliper1further comprises at least one detecting device15, adapted to detect a biasing force directed in axial direction X-X.

Advantageously, said detecting device15of the brake caliper1is interposed in axial direction X-X, either directly or indirectly, e.g. by the interposition of one or more components, e.g. such as a slewing ring body29and/or a slider32, between said plate back23of said second brake pad20of said pair of brake pads10,20and an elongated portion7of the caliper body4.

According to a preferred embodiment, the provision of an actuator16between said detecting device15and said plate back23of said second brake pad20of said brake pad pair10,20is avoided.

Improved measurement accuracy of the axial force exchanged between said second brake pad20and said second elongated portion7caliper body4is achieved by avoiding the provision of an actuator16axially placed between the detecting device15and the plate back23of the second brake pad20.

Such a detecting device15, which is therefore located axially between the caliper body4and the second brake pad20, allows a precise and reliable measurement of the axial force exchanged with the brake disc during the braking action, which takes into account the effect of the friction between the brake caliper components in relative motion, e.g. in a relative sliding motion, as well as deformation of parts of the caliper body and/or the brake caliper itself.

Furthermore, the estimate of the axial force exchanged with the disc which can be obtained with such a detecting device15, makes it possible to carry out a loop control with feedback on the thrust means. For example, such an estimate of the exchanged axial force can be stored by a control unit and compared with the power supply of an electric motor driving the thrust means of an electro-actuated brake caliper to diagnose possible malfunctions.

For example, in the case of a floating or axially sliding caliper, the friction due to the sliding of the axially sliding portion of the brake caliper necessarily generates a dissipation of the mechanical power generated by the electric motor. By virtue of such a detecting device15, it is possible to estimate the force actually exchanged with the disc and therefore to evaluate the dissipations which arise due to friction.

According to a preferred embodiment, said connecting device15comprises at least one load cell25. Preferably, said load cell25comprises at least one piezoelectric element.

According to an embodiment, said load cell25is adapted to work by deflection. In this manner, the load cell25is provided, for example, with a strain gage which detects the elongation of a deflected portion of the load cell body when measuring the force exchanged with the brake disc.

According to an embodiment, said load cell25is adapted to work in compression.

According to an embodiment, said load cell25comprises at least one contact ridge26,26′, adapted to define a stretch of axial contact27,27′ against a body axially abutting against said load cell25.

According to an embodiment, said load cell25comprises at least two contact ridges26and26′, axially opposed to each other and the body of load cell25, each contact ridge26or26′ of said at least two contact ridges26,26′ is adapted to define an axial contact stretch27,27′ against a body axially opposed to said load cell25.

According to an embodiment, said axial contact stretch27,27′ is at least an arc of a circumference. According to an embodiment, said axial contact stretch27,27′ is a circumference.

According to an embodiment, the detecting device15comprises a connector52adapted to form an operational connection to a brake control, e.g. by means of one or more transducer units. According to an embodiment, said connector52comprises at least one sealing portion33″, e.g. a collar53, to achieve a mechanical interference coupling with a portion of the caliper body4. Preferably, said collar53applies a retaining action. According to an embodiment, said caliper body4, and preferably said second elongated portion7of the caliper body4delimits an access channel to the load cell25which receives said connector52.

According to an embodiment, said load cell25has an annular body which develops about a through opening28. In this manner, it is possible to accommodate other components of the brake caliper1at least partially inside said through opening29, thereby reducing the axial dimensions of the caliper body4. In this manner, it is possible to accommodate an anti-rotation device at least partially in the through opening29of the load cell25, for example.

According to an embodiment, said detecting device15comprises at least one slewing ring body29interposed in axial direction X-X between said plate back23of said second brake pad20and said load cell25.

According to an embodiment, said at least one slewing ring body29is adapted to abut axially against said contact ridge26of the load cell25.

According to an embodiment, said at least one slewing ring body29has an annular body which surrounds a through opening of slewing ring body. Preferably, said a through opening of a slewing ring coupling body is in axis, or coaxial, with said through opening29of the load cell25.

According to an embodiment, said detecting device15further comprises at least one elastic device30.

According to an embodiment, said elastic device30is adapted to apply a direct preload action in axial direction X-X between said load cell25, and preferably said contact ridge26of the load cell25, and said at least one slewing ring body29.

According to an embodiment, said elastic element30comprises one or more conical spring washers47. Preferably, said elastic device comprises a plurality of conical spring washers47stacked in axial direction X-X.

According to an embodiment, said elastic device30further comprises a regulating device46, e.g. comprising an adjustment screw cooperating with a nut, said adjustment device46being adapted to carry said slewing ring body29into axial abutment on said load cell25, thereby applying a preload action. The measurement error of the load cell25is minimized in this manner.

According to an embodiment, said plurality of conical spring washers47has an annular body which embraces the stem48of said adjustment screw of said adjustment device46. According to an embodiment, the head50of the adjustment screw of the adjustment device46abuts axially against said slewing ring body29, thereby biasing it axially against said load cell25.

According to an embodiment, said elastic device30comprises at least one abutment body49which forms an axial abutment surface for said plurality of conical spring washers47to apply said preload action. For example, said abutment body49is essentially cup-shaped with a through opening in its bottom wall. By virtue of the provision of such an abutment body49, said elastic device30forms a cartridge system with said adjustment device46which can be inserted axially into the brake caliper body1.

According to an embodiment, said second elongated portion7of the caliper body4comprises at least one axial guiding wall31, which extends in axial direction X-X between said plate back23of the second brake pad20and said load cell25.

According to an embodiment, said detecting device15further comprises at least one slider32, preferably associated in sealed manner with said at least one axial guiding wall31, e.g. through the interposition of an O-ring33, said at least one slider32cooperating with said at least one axial guiding wall31to slide in axial direction X-X when pushed by said second brake pad20during the braking action.

According to an embodiment, said at least one slider32comprises at least one axial guiding counter-wall34in contact with said at least one axial guiding wall32of the caliper body4to a predetermined axial extension X3.

According to an embodiment, said at least one slider32comprises an abutment surface36, adapted to abut axially against said plate back23of said second brake pad20.

Therefore, such a slider32is only adapted to bias the load cell25in an axial direction either directly or indirectly through the interposition of the said slewing ring body29.

The provision of said at least one contact ridge26defining a contact section27,27′ with said slewing ring body29and/or with said slider32, guarantees that only axial stresses are transmitted to the load cell25, thereby avoiding the transmission of flexural or torsional stresses, which could interfere with the reading of the detecting device15. Preferably, said at least two contact ridges26,26′, when observed, in section ideally define a single point of contact with said slewing ring body29and at least one point of contact with an annular abutment body38.

Preferably, said at least two contact ridges26,26′ are placed at different diameters of the annular body of the load cell to form two contact circumferences27,27′ which are substantially concentric and coaxial. Preferably, a strain gage is applied between the two contact ridges26,26′ to detect the elongation due to the bending of the annular body of the load cell25between said two contact ridges26,26′.

According to an embodiment, said slider32is made of thermally insulating material, e.g. phenolic resin. In this manner, the load cell25is protected from interferences caused by thermal stress. Preferably, said slider32is unsuitable for deformation by the effect of thermal stress when under operating conditions.

According to an embodiment, one or more seals are associated with the load cell body25to provide a protective seal against infiltrations.

According to an embodiment, an annular abutment body38, e.g. made of steel, is associated with the body of load cell25to form an axial abutment and radial positioning reference for the load cell25. The provision of such an annular body38also makes it possible to form a non-deformable abutment reference in operating conditions.

According to an embodiment, said detecting device15comprises at least one sealing element33,33′,33′″, and preferably a plurality of sealing elements33,33′,33′″, which define a sealed chamber35which receives at least said load cell25. In this manner, foreign bodies, as well as liquids, are prevented from interfering with the reading of the load cell25. According to an embodiment, said sealing elements comprise O-rings and/or sealed threaded connections.

According to an embodiment, a pneumatic device37is provided to eject, and to assemble, at least one component from the said sealed chamber35defined by the detecting device15. Indeed, by virtue of said pneumatic device37which comprises a pipe, an undesirable increase in chamber pressure, which could lead to failure to reach the resting position of the slider32, is avoided.

Preferably, said pneumatic device37comprises at least one pipe leading onto a wall of said slider32, e.g. said abutment surface36, to disassociate said slider32from the caliper body4when activated, e.g. by blowing compressed air. Disassembly operations are facilitated in this manner.

According to an embodiment, said actuator16of the thrust device14is associated with an electrically powered motor41. For example, said motor41comprises a rotor and a stator both received in the caliper body4, and preferably in the first elongated portion5of the caliper body4.

According to an embodiment, said brake caliper1further comprises a bracket42comprising fixing means43for fixing said brake caliper1for a vehicle40.

According to an embodiment, said caliper body4is adapted to slide in axial direction X-X with respect to the bracket42to apply the braking action. In this manner, a floating brake caliper1is made.

According to an embodiment, said caliper body4is made in a single piece. In other words, it is a monobloc. Preferably, said caliper body4is made with a single casting.

According to an embodiment, said caliper body4is monobloc and is adapted to slide on the bracket42.

According to a general embodiment, a disc brake system2comprises at least one brake caliper1according to any one of the embodiments described above.

Said disc brake system2further comprises at least one disc3. Said disc3defines a rotation axis A-A. In said disc brake system2an axial direction X-X is defined either coinciding with or parallel to the rotation axis A-A- of the disc3of the disc brake2, a radial direction R-R orthogonal to the axial direction X-X, and a tangential direction T-T, orthogonal to both the axial direction X-X and to the radial direction R-R.

According to a preferred embodiment, said disc brake system2further comprises at least one braking control. Preferably, said braking control comprises a control lever.

Preferably, the term “braking control” means a control interface intended to receive a control from a driver of the vehicle40to apply a braking action.

Preferably, the term “braking action” means the clamping action of the opposite braking surfaces6,8applied by the opposite brake pads10,20of the brake caliper1when activated by the thrust device14, thereby generating a braking torque.

Preferably, the term “braking torque” means the force generated by the brake pads10,20to brake the disc3applied on the opposite braking surfaces6,8at a predefined radial distance from the rotation axis A-A of the disc3.

According to an embodiment, said disc brake system2comprises at least one electric motor41for the activation of said thrust device14.

According to an embodiment, said disc brake system2comprises at least one transducer unit operationally connected to said braking control and said detecting device15.

Preferably, said at least one transduction unit is configured to transmit a control signal to said thrust device14, e.g. by activation of said electric motor41, based on a control action transmitted by the braking control when activated by the driver of the vehicle.

According to a general embodiment, the vehicle40comprises at least one disc brake2according to any one of the embodiments described above.

Preferably, said vehicle40is a motorcycle40.

For example, said motorcycle40is adapted to lean when cornering.

According to an embodiment, said motorcycle40comprises at least one fork51associated with said bracket42through fixing means43.

According to an embodiment, said first elongated portion5of the caliper body4, which receives said electric motor41of the brake caliper1, is placed on the side of disc3facing said fork51, projecting axially beyond the axial level of said fork51by a predetermined amount55.

According to an embodiment, said second elongated portion7of the caliper body4, comprising said detecting device15, is placed on the side of disc3facing the motorcycle wheel56.

According to an embodiment, said braking control17comprises a control lever preferably associated with the handlebar of the motorcycle40.

According to an embodiment, at least one detecting device15, adapted to detect a biasing force directed in axial direction X-X.

Said detecting device15comprises at least one load cell25.

Said load cell25comprises at least one contact ridge26,26′, adapted to define an axial contact stretch27,27′ preferably a circumference against a body axially abutting against said load cell25. Preferably, said body axially abutting against said load cell25is a brake pad10,20. In this manner, it is possible to detect the axial force exchanged between the brake disc and the brake pad10,20which is the first member of the brake caliper which provides the force to the brake disc during the braking action.

According to a preferred embodiment, said load cell25has an annular body which develops about a through opening28.

According to an embodiment, said detecting device15comprises at least one of the features described in any one of the embodiments described above.

According to a general embodiment, a vehicle is provided comprising at least one detecting device according to any one of the embodiments described above. According to an embodiment, said vehicle is a car. According to an embodiment, said vehicle is a motorcycle.

By virtue of the features described above, provided either separately or in combination, it is possible to respond to the needs mentioned above, and to obtain the aforesaid advantages, in particular:the brake control, typically a control lever and/or brake pedal, is provided with feedback on the force exchanged between brake pad and caliper body;it provides an electro-actuated floating brake caliper with unusual performance in terms of control by the driver of the vehicle even in emergency situations, as well as improved comfort for the driver of the vehicle;it is possible to detect, as needed, only the axial stress exchanged between brake pad and caliper body, avoiding to detect shear, bending and/or torsional stress;it is possible to house a body, e.g. an elastic device, within the overall dimensions of the load cell25, thereby reducing the overall dimensions of the brake caliper, the performance being the same;a compact caliper body is provided, particularly in the axial direction, reducing the axial dimension of the cantilevered portion of the brake caliper.it is possible to integrate the anti-rotation in the piston and not in the caliper body, thereby resulting in a further reduction of dimensions;it is possible to make the monoblock caliper body, even in the case of a floating brake caliper;the brake caliper can be mounted from a single axial side of the brake disc;it is possible to preload the sensor impacting on external dimensions, using a masked volume;it makes it possible to simplify the transmission-screw mechanical layout for the removal of the sensor component and above all of the management of electrical contacts.

The person skilled in the art may make many changes and adaptations to the embodiments described above or may replace elements with others which are functionally equivalent to satisfy contingent needs without however departing from the scope of the appended claims.

LIST OF REFERENCES

1. Brake caliper2. Disc brake system, or disc brake3. Disc brake disc4. Caliper body5. First elongated portion of the caliper body6. First braking surface of the disc7. Second elongated portion of the caliper body8. Second braking surface of the disc9. Caliper body bridge10. First brake pad11. Friction material of the first brake pad12. Support plate of the first brake pad13. Back plate of the first brake pad14. Thrust device15. Detecting device16. Actuator18. Housing bottom wall19. Housing edge20. Second brake pad21. Friction material of the second brake pad22. Support plate of the second brake pad23. Back plate of second brake pad25. Load cell26,26′ Contact ridges27,27′. Contact stretches28. Through opening of the load cell29. Slewing ring body30. Elastic device31. Guide axial wall32. Slider33,33′,33′″ Sealing element34. Axial guiding counter-wall35. Sealed chamber of the detecting device36. Slider abutment surface37. Ejection device38. Abutment annular body40. Vehicle or motorcycle41. Electric motor42. Brake caliper bracket43. Fixing means44. Thrust device piston45. Seal46. Adjustment device47. Conical spring washer48. Adjustment screw stem49. Abutment body50. Adjustment screw head51. Fork52. Connector53. Collar55. Cantilevered axial extension56. WheelA-A. Disc rotation axisX-X. Axial directionR-R. Radial directionT-T. Tangential direction