System and method for determining braking torque by a force sensing device at the interface between a brake caliper body and a hub holder

Abstract

The device 1 is adapted to detect a braking force applied by a brake caliper 10 to a hub holder 20 during and due to a braking event. The device is adapted to be attached to a clamping interface (i, ii) between the brake caliper 10 and a hub holder or brake caliper support 20 by means of a clamping means 60 that applies a clamping force. The device 1 comprises a low-friction body 2, a caliper-hub holder element 3, a sensor element 4, and an electrical interface 5. The low-friction body 2 is in the form of a washer or a disc-shaped plate and is adapted to be tightly attached to the brake caliper 10 and the hub holder 20 at the fastening interfaces (i, ii). The caliper-hub holder connecting element 3 is connected integrally with the low-friction body and is mechanically connected to both the brake caliper 10 and the hub holder 20 when the detection device 1 is attached, and is adapted to determine the mechanical connection through which the braking force is at least partially released. The caliper hub holder connection element 3 is deformable such that the strain and / or stress present in the caliper hub holder connection element 3 depends on the total force acting on the caliper hub holder connection element 3. The low-friction body 2 is configured to decouple the clamping force from the braking force to minimize the effect of the clamping force on the detection device 1 so that the deformation and / or strain of the caliper hub holder connection element 3 is representative of the aforementioned forces resulting from a braking event. The sensor element 4 is connected to the caliper hub holder connection element 3 and configured to detect the strain present in the caliper hub holder connection element 3 and generate at least one electrical signal S indicative of the detected strain and representative of the braking force. An electrical interface 5 is connected to the sensor element 4 for conducting and making available the at least one generated electrical signal S. Corresponding methods and systems for determining braking torque are also described.

Description

[Technical Field]

[0001] The present invention relates to a device for detecting braking forces, adapted to be mounted at the fixed interface between a brake caliper and a respective hub holder.

[0002] The present invention further relates to a braking torque measurement system that uses the above-described device and method.

[0003] The invention further relates to a brake caliper assembly comprising at least one of the devices described above. [Background technology]

[0004] For controlling, monitoring and operating a braking system, for example an electronically controlled disc brake system, it is very useful to know in real time, and as accurately as possible, the braking force or torque values ​​applied by the brake calipers of the braking system during braking operations.

[0005] However, it is difficult to directly, accurately and reliably measure the braking force and / or torque applied by the brake calipers of a braking system.

[0006] In this regard, the prior art tends to determine braking torque and / or force based on indirect measurements that refer to quantities closely related to braking torque and / or force, for example forces acting at different points on a brake caliper.

[0007] On the other hand, it is necessary to take into account the need to use sensor devices that are as small and compact as possible so that they can be easily integrated into the braking system without causing functional problems.

[0008] Several miniature sensor devices are known in this regard which are capable of detecting and / or measuring lateral (shear) forces acting between the brake caliper support and the vehicle hub using strain sensors.

[0009] Various types of sensors are known in the literature that are interposed between the caliper and the hub holder and utilize different force or strain or stress sensor technologies.

[0010] Cylindrical (i.e., "washer-type") sensors are also known that provide information about braking torque from deformations caused by friction forces at the interface between the caliper and hub holder. These concepts cannot ignore the presence of threads, which are used to generate the friction forces essential to counteract the tangential stresses caused by braking.

[0011] However, the results obtained with such devices are highly dependent on the tightening torque of the screws used to fasten the two parts whose force is being measured, which in turn depends heavily on the axial force, which is a disturbance to the accuracy of the braking force and / or torque estimation.

[0012] In view of the above, there is a strong need to devise a device that more accurately detects the force exerted by the brake caliper on the hub holder due to braking action, and minimizes the influence of the clamping force on the results.

[0013] There is also a strong felt need for an apparatus and method for more accurately determining braking torque and / or force through measurements made at the interface between the brake caliper body and the brake caliper support or hub holder.

[0014] For this application, additional requirements for the measuring device are compactness, robustness, ease of installation (e.g. using the fixing system already provided for fixing the brake caliper), and versatility of use in the context of fixed or floating caliper disc brakes.

[0015] As mentioned above, the above requirements are not fully met by the solutions currently available from the prior art. Summary of the Invention

[0016] The object of the present invention is to provide a braking force detection device that is able to at least partially overcome the drawbacks mentioned above with reference to the prior art and to address the aforementioned needs that are particularly felt in the technical field considered.

[0017] These and other objects are achieved by a detection device according to claim 1.

[0018] Some advantageous embodiments of such a method are the subject matter of dependent claims 2-17.

[0019] It is a further object of the present invention to provide a corresponding braking torque measurement system adapted to determine braking torque resulting from the implementation of a vehicle braking system and employing said device.

[0020] This object is achieved by the process according to claim 18.

[0021] Some advantageous embodiments of such a system are the subject of dependent claims 19 to 22.

[0022] It is a further object of the present invention to provide a brake caliper assembly for a vehicle braking system comprising at least one of the aforementioned detection devices.

[0023] These and other objects are achieved by the device according to claim 23.

[0024] Advantageous embodiments of such a brake caliper assembly are the subject of dependent claim 24.

[0025] It is a further object of the present invention to provide a vehicle braking system that includes a plurality of brake caliper assemblies.

[0026] These and other objects are achieved by a braking system according to claim 25.

[0027] Finally, an object of the present invention is to provide a method for measuring braking torque, configured to determine the braking torque resulting from the operation of a vehicle brake system by detection performed at at least one fixed interface between the brake caliper and the respective hub holder or support 20.

[0028] These and other objects are achieved by the method according to claim 26.

[0029] Some advantageous embodiments of such a system are the subject of dependent claims 27-28.

[0030] Further features and advantages of the devices, systems and methods according to the invention will become apparent from the following description of preferred embodiments thereof, given as non-limiting examples with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 1 is a perspective view of a braking force detection device according to one embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of a further embodiment of the device according to the invention. [Figure 3] FIG. 3 is a perspective view showing an exploded view of a further embodiment of the device. [Figure 4] FIG. 4 is a perspective view showing an exploded view of a further embodiment of the device. [Figure 5] FIG. 5 is a perspective view showing an exploded view of a further embodiment of the device. [Figure 6]FIG. 6 shows a respective embodiment of inserting a device according to one of the figures 1 to 5 into a brake caliper assembly according to the invention. [Figure 7] FIG. 7 shows a respective embodiment of inserting a device according to one of FIGS. 1 to 5 into a brake caliper assembly according to the invention. BEST MODE FOR CARRYING OUT THE INVENTION

[0032] A detection device 1 for detecting a braking force exerted by a brake caliper 10 on a hub holder or brake caliper support 20 during and resulting from a braking event is described with reference to Figures 1 to 7.

[0033] Such a detection device 1 is adapted to be mounted at a fixed or clamping interface (i, ii) between a brake caliper 10 and a hub holder or brake caliper support 20 by means of clamping means 60 that apply a clamping force.

[0034] The device 1 consists of a low-friction body 2, a caliper-hub-holder connecting element 3, and furthermore at least one sensor element 4 and an electrical interface 5.

[0035] The low friction body 2 is in the form of a washer or a plate or a bearing.

[0036] The caliper-hub holder connection element 3 is connected to the aforementioned low friction body and is integral therewith.

[0037] Furthermore, the caliper-hub holder connection element 3 is adapted to be mechanically connected to both the brake caliper 10 and the hub holder or brake caliper support 20 when the detection device 1 is mounted on the fixed interface (i, ii), resulting in a mechanical connection that at least partially discharges the aforementioned braking forces from the brake caliper 10 to the hub holder or brake caliper support 20.

[0038] The caliper-hub holder connection element 3 is deformable such that the deformation and / or strain present locally in the caliper-hub holder connection element 3 depends on the overall force acting on the caliper-hub holder connection element 3 .

[0039] The aforementioned low-friction body 2 is configured to decouple the clamping force (caused by the clamping means, e.g., screws) from the braking force and minimize the effect of the clamping force on the detection device 1, so that the aforementioned deformations and / or distortions present in the caliper-hub holder connection element 3 are representative of the braking force, by the caliper-hub holder connection element 3, resulting from a braking event applied by the brake caliper 10 to the hub holder or brake caliper support 20.

[0040] At least one sensor element 4 is operably connected to the caliper hub holder connection element 3 and configured to detect deformation and / or strain present in the caliper hub holder connection element 3 and generate at least one electrical signal S indicative of the detected deformation and / or strain and representative of the braking force.

[0041] An electrical interface 5 is connected to the sensor element 4 for conducting and making available the at least one generated electrical signal S.

[0042] According to an implementation option of the device, the low friction body 2 consists of a bearing.

[0043] According to a particular implementation option, such a bearing is a plain bearing.

[0044] According to another embodiment, such bearing is an axial thrust bearing, a ball bearing or a roller bearing.

[0045] According to another implementation option of the device, the aforementioned low-friction body 2 consists of a layer of low-friction polymeric material or another anti-friction element made of a material with a low coefficient of friction.

[0046] According to another embodiment, the low-friction body 2 consists of an element made of a metallic and / or ceramic and / or polymer material, provided with a low-friction coefficient coating.

[0047] According to various possible embodiments, the low-friction body 2 consists essentially of a disk-shaped or washer-shaped plate.

[0048] According to another implementation option of the device, the aforementioned low-friction body 2 consists of a metal washer coated with a low-friction material.

[0049] According to various possible embodiments, the washer is made of steel or aluminum or titanium or cast iron.

[0050] According to various possible embodiments, the anti-friction coating is generally made of DLC (Diamond-Like-Carbon), TiN, PTFE, WC, TiCN, CrN, ZrN, PLC, CL, or other anti-friction materials.

[0051] It should be noted that the function of the anti-friction element is to ensure that the physical connection between the caliper and the hub holder is as free as possible from interface friction forces.

[0052] In other words, the purpose of the low friction element is to decouple the load (or force) resulting from the tightening of the caliper fixing screws from the load (or force) resulting from the braking torque. In this way, the caliper is free to move tangentially under torque, thereby applying load to the caliper hub connecting element 3 in which the sensing or sensor element 4 is housed.

[0053] In this case, the brake caliper 10 is therefore connected to the hub holder 20 (or brake caliper support 20 ) by the usual necessary fastening means (for example screws) or connecting elements or bushings 3 .

[0054] It is noteworthy that in this fastening method, the tightening means, e.g., a screw, has the function of generating only axial translational constraint on the caliper, while the caliper-hub holder connection element 3 has the job of generating translational constraint in a plane passing through the caliper hub contact surface and the rotation surface.

[0055] In particular, this makes it possible to reduce the size of the screw, if desired, whose function, as mentioned above, no longer consists in the generation of frictional forces (due to axial load) on the caliper-hub-holder contact surface necessary to counteract the forces generated during braking operations.

[0056] In this way, the caliper-hub holder connecting element 3 at least partially or entirely transmits the braking force, i.e. the load due to the braking torque transmitted to the hub holder 20. In other words, such a caliper-hub holder connecting element 3 may also be referred to as a "load element" or a "carrier element."

[0057] According to an embodiment of the detection device 1 (particularly as described in the implementation options shown in FIGS. 3 to 5), the caliper-hub-holder connecting element 3 comprises a bushing 32 and a disk-shaped annular plate 33 .

[0058] In the embodiment shown in Figures 3 and 4, the annular disc-shaped plate is a disc-shaped crown base or flange located at one end of the caliper-hub-holder connecting element 3, the end of the device 1 intended to come into contact with the brake caliper when the device is installed.

[0059] In the example shown in FIG. 5, the annular disk is disposed at the mouth except for both ends.

[0060] According to an embodiment (shown in Figures 1 to 5, and in particular in more detail in Figures 3 to 5), the detection device 1 further comprises a shimming washer 7 configured to adapt the thickness of the detection device 1 to the dimensional and / or functional requirements of the fixing interfaces (i, ii).

[0061] In that case, the aforementioned shimming washer 7 can perform the additional function of protecting the anti-friction element: for example, if the anti-friction element is made of a bearing resting on an aluminum surface, the shimming washer 7 prevents the aluminum surface on which the bearing roller rests from being etched.

[0062] According to an embodiment of this device (shown in Figures 1 to 5, and more particularly in Figures 3 to 5), the aforementioned low-friction body consists of a low-friction element 2 that is interposed in contact between the disc-shaped annular plate 33 of the caliper-hub holder connecting element 3 and the shimming washer 7.

[0063] The disc-shaped annular plate 33 is adapted to be placed in close frictional contact with a surface of the brake caliper 10 when the detection device 1 is mounted to the fixed interface (i, ii), and the shimming washer 7 is adapted to be placed in close frictional contact with a surface of the hub holder or brake caliper support 20.

[0064] It is worth noting that the lower the friction between the caliper-hub-holder connecting element 3 and the shimming washer 7, the higher the proportion of braking force that reaches the sensor element. In other words, as the coefficient of friction decreases, the efficiency of the measurement system increases.

[0065] According to an implementation option, the bushing 32 is a steel bushing adapted to be inserted into the hub holder 20 .

[0066] According to an implementation option, said bushing 32 comprises a recess 30 adapted to receive a portion of said fastening means 60 when the detection device 1 is mounted on the fixed interface (i, ii).

[0067] According to an implementation option, the bushing 32 defines a tubular passage adapted to be traversed by the cylindrical threads of the respective screw when the detection device 1 is mounted on the fixed interface (i, ii).

[0068] According to an implementation option, said bushing 32 includes at least one housing 31 configured to accommodate each at least one sensor element 3. Such housing 31 is arranged at a respective sensing location corresponding to a highly deformable bushing portion.

[0069] In fact, the connection ensured by the bushing 3 in use is characterized by zones of constant high load, which make it easy to identify the areas where the sensing elements must be installed.

[0070] The size and position of the housing 31, and each sensor element 4, are determined by testing and experimentation so that the sensor elements 4 are subjected to stresses that optimize their function, i.e., biases that are not too low to impair measurement accuracy, but not too high to damage the sensor itself under overload conditions.

[0071] According to a mounting option, the bushing 32 is adapted to be tightly mounted to both the brake caliper and the hub holder, resulting in a clearance-free coupling.

[0072] In this case, when the brake caliper is subjected to loads occurring during a braking event, it transfers these loads by direct contact to the bushing, which in turn transfers these loads by direct contact to the hub holder, causing a local deformation of the bushing in which the sensor element 4 is located.

[0073] According to an implementation option, the aforementioned bushing 3 is adapted to be coupled with a small clearance on both the side of the brake caliper 10 and on the side of the hub holder 20 when the detection device 1 is mounted on the fixed interface (i, ii).

[0074] The aforementioned clearances are for ease of assembly.

[0075] For the rest, from a functional point of view, the operation is similar to that already described for the case without clearance. When the brake caliper is subjected to the loads that occur during a braking event, it "leans" against the bushing and transmits the load to it, which in turn "leans" against the hub holder and transfers the load to it. The latter contact locally deforms the bushing in which the sensor element 4 is located.

[0076] It is worth noting that in different parts of the bushing there may be different deformations and / or resulting strains, which are therefore local, but all depend in some way on the applied load and consequently on the braking torque.

[0077] It is worth noting that the bushing 32 is designed so that for foreseeable stress levels, the strain experienced remains in the elastic range and is therefore not permanent.

[0078] Advantageously, the sensor element 4 is arranged at a detection position corresponding to a part where the influence of a force or load causes a high deformation.

[0079] According to an embodiment of the device 1, said sensor element 4 is a deformation or strain sensor 4.

[0080] Even in this case, it is possible to trace back from deformation to strain according to a relationship known per se or experimentally obtained for a particular bushing.

[0081] According to implementation options, the strain sensor 4 is a strain gauge, for example a rosette or a unidirectional strain gauge known per se.

[0082] According to other possible implementation options, said sensor element 4 is a mechanical or optical or acoustic or pneumatic or electrical strain gauge.

[0083] According to various specific implementations, the sensor element 4 is a fiber optic strain sensor, or a piezoresistive sensor, or a resonator-on-silicon sensor, or an inductive transducer.

[0084] According to other implementation options, the sensor element 4 may consist of any type of sensor known per se and capable of reading / detecting strains or deformations.

[0085] According to another implementation option, the sensor element 4 consists of a force sensor.

[0086] According to an embodiment of the device, the caliper-hub-holder connecting element 3 and the low-friction body 2 are integrated into a single element.

[0087] According to an embodiment, the low friction body consists of an anti-friction coating disposed on the disk-shaped base 33 of the caliper-hub-holder connecting element 3 .

[0088] According to an embodiment (for example shown in FIGS. 14 and 5), the detection device 1 consists of a single sensor element 4.

[0089] According to an embodiment, the detection device 1 is made up of a number of sensor elements 4 .

[0090] According to another embodiment (for example shown in FIGS. 2 and 3), the detection device 1 consists of three sensor elements 4 .

[0091] For example, each bushing may have three strain gauges mounted at 120°.

[0092] Referring again to Figures 1 to 7, a braking torque measurement system is described that is configured to determine the braking torque resulting from the operation of a braking system for a vehicle by detection performed at at least one fixed interface (i, ii) between a brake caliper 10 and a respective hub holder or support 20.

[0093] The braking torque measurement system comprises at least one detection device 1 (also shown as D1 or D2 in Figures 3 and 4) according to any of the above-mentioned embodiments, pressed between the brake caliper body 11 of the brake caliper 10 and the hub holder or brake caliper support 20 at at least one respective fixing interface (i, ii). Such an arrangement is shown in Figures 6 and 7.

[0094] The braking torque measurement system further comprises a clamping means 60 configured to clamp the brake caliper 10 and the hub holder or brake caliper support 20 and to press the detection device 1 between the brake caliper body 11 of the brake caliper 10 and the hub holder or brake caliper support 20.

[0095] The braking torque measurement system further comprises electronic processing means operatively connected to said electrical interface 5 and adapted to receive said at least one electrical signal S.

[0096] The electronic processing means are configured to determine a braking torque based on the at least one electrical signal S representative of the braking force acting on each detection device.

[0097] According to an embodiment, the braking torque measurement system comprises a number of detection devices D1, D2 at each fixed interface (i, ii).

[0098] In that case, the electronic processing means is configured to determine the braking torque based on the respective plurality of electrical signals S from the respective detection devices D1, D2.

[0099] According to the embodiment shown in Figures 3 and 4, the brake torque measurement system comprises a first detection device D1 at a first fixed interface (i) between a first caliper body portion and a hub holder or a first part of the brake caliper support, and further comprises a second detection device D2 at a second fixed interface (ii) between a second caliper body portion and a second part of the hub holder or brake caliper support.

[0100] According to one embodiment of the braking torque measurement system, the electronic processing means comprises a control unit and / or processor configured to calculate the braking torque based on the at least one electrical signal S by one or more algorithms executed by one or more software programs.

[0101] According to an embodiment, the system comprises a plurality of detection devices and the electronic processing means calculates the braking torque based on the respective plurality of electrical signals S by means of one or more algorithms executed by one or more software programs.

[0102] According to various implementation options of the system, the electronic processing means (which may also be defined as an "acquisition system") are configured to determine the braking torque based on the electrical signal S representative of the detected deformation and / or the detected strain and / or the detected force by means of the algorithms and / or procedures described below which exemplify the method according to the invention.

[0103] Through algorithms executed by one or more software programs, the use of multiple detection devices and / or multiple sensor elements for each device advantageously makes it possible to identify the operating condition of the vehicle (e.g., forward / reverse gear).

[0104] According to one embodiment of the braking torque measurement system, the tightening means 60 comprises at least one screw 61, 62 comprising a screw anti-friction element arranged below the screw head.

[0105] In this way, the force transmitted by the underhead of the screw due to the braking torque is also cancelled out and all the force generated by the braking torque passes through the connecting part 3, through the sensor element 4, is read and converted into a torque reading.

[0106] 6 and 7, there is described a brake caliper assembly for a vehicle braking system comprising a brake caliper 10, a brake caliper hub holder or support 20, at least one detection device 1 according to any one of the previously illustrated embodiments, and a clamping means 60 configured to clamp the brake caliper 10 and the brake caliper hub holder or support 20 together and to press the detection device 1 between the brake caliper body 11 of the brake caliper 10 and the brake caliper hub holder or support 20.

[0107] At least one detection device 1 is pressed between the brake caliper body 11 of the brake caliper 10 and the hub holder or brake caliper support 20 at each at least one fixing interface (i, ii).

[0108] According to an embodiment, the brake caliper assembly comprises a first detection device D1 fixed at a first fixing interface i between the brake caliper body 11 of the brake caliper 10 and the hub holder or brake caliper support 20 by a first fixing bolt 61, and further comprises a second detection device D2 fixed at a second fixing interface ii between the brake caliper body 11 of the brake caliper 10 and the hub holder or brake caliper support 20 by a second fixing bolt 62.

[0109] According to different possible implementation options, the brake caliper is a fixed or floating disc brake caliper, or a caliper with radial and axial connections, or a monoblock or floating caliper.

[0110] The present invention is a brake system for a vehicle, characterized in that it comprises a plurality of brake caliper assemblies according to any one of the above-described embodiments.

[0111] The present invention also provides a braking system for a vehicle, including a braking torque measurement system according to any one of the above-described embodiments.

[0112] In the following, a method is described for determining the braking torque resulting from the operation of a braking system for a vehicle by detection performed at at least one fixed interface (i, ii) between the brake caliper 10 and the respective hub holder or support 20.

[0113] The method includes first inserting at least one detection device 1 (D1, D2 in Figures 6 and 7) according to any one of the above-mentioned embodiments at at least one fixing interface of the brake caliper 10 so that the detection device 1 is fixed and pressed between the brake caliper body 11 and the hub holder or brake caliper support 20 of the brake caliper 10.

[0114] Next, the method provides for detecting the braking force applied by the brake caliper 10 on the hub holder or brake caliper support 20 by each of the aforementioned at least one detection device 1 during a braking event, and generating at least one respective electrical signal S representative of the detected braking force.

[0115] The method further comprises the steps of transmitting said at least one electrical signal S to electronic processing means (or acquisition means) and processing said at least one electrical signal S by the electronic processing means to determine the braking torque.

[0116] According to one embodiment of the method, the inserting step comprises inserting a plurality of detection devices D1, D2 into respective fixed interfaces i, ii, respectively.

[0117] In this case, the processing step comprises determining a braking torque based on a plurality of electrical signals S from each of the sensing devices D1, D2, respectively.

[0118] According to an embodiment of the method, the processing step consists of calculating, by electronic processing means, a braking torque based on the at least one electrical signal S as mentioned above, by one or more algorithms executed by one or more software programs.

[0119] According to an embodiment, the calculating step comprises calculating the braking torque according to a predetermined relationship between braking torque and braking force represented by a computerized model or look-up table accessible by electronic processing means.

[0120] For example, the aforementioned predetermined relationship is determined through an experiment and / or characterization and / or calibration step performed after at least one detection device 1 is placed and fixed at the respective fixation interface.

[0121] According to another embodiment, the calculating step comprises calculating the braking torque according to a predetermined non-linear relationship between the braking torque and the deformation and / or strain detected by the at least one strain and / or stress sensor 4 at each position arranged in contact with the carrier element.

[0122] Such a predetermined non-linear relationship may be represented, for example, by a computerized model or look-up table stored so as to be accessible by electronic processing means.

[0123] Said predetermined relationship is determined by an experiment and / or characterization and / or calibration step carried out after at least one detection device 1 is placed and fixed at the respective fixation interface.

[0124] According to an implementation option, the method comprises detecting the deformation of the loaded connecting element (or bushing) and calculating the strain stress based on the deformation, the progression from deformation to strain being easily obtainable by an acquisition device, i.e., electronic processing means, according to a relationship known per se or obtained experimentally.

[0125] According to an embodiment, the method further comprises the steps of testing a braking torque measurement system including a detection device with a plurality of sensor elements, then identifying the most stressed sensor element, and finally identifying the respective position as the most suitable position, in such a case the method then provides for installing only one sensor element in the detection device at the most suitable position identified by the test.

[0126] Below some further details of the working principle of the method according to the invention are provided.

[0127] The braking torque generates a load (e.g., a shear load) on the caliper-hub-holder connection element (i.e., on the carrier element).

[0128] The term "load" refers to the forces generated by frictional phenomena during braking, transmitted to the brake caliper (through the pad-caliper interface) and ultimately released to the hub holder through the caliper block-hub holder mechanical connection.

[0129] It is worth noting that the forces generated can have both tangential and radial components, not just tangential.

[0130] In this regard, according to an embodiment of the method (and according to a corresponding embodiment of the apparatus), the sensor element is positioned so as to be aligned with the force product.

[0131] In other words, the force resulting from braking is transmitted to the brake caliper, which then transmits it to the bushing, which then transmits the force to the hub holder. When transmitting the load to the hub holder, the bushing undergoes local deformation at the position where the sensing element is located (or at the positions where the sensing elements are located, if there are multiple sensing elements).

[0132] In this example, the sensing element detects a deformation representative of the force that the brake caliper applies to the hub holder (due to the fact that the anti-friction element minimizes and ideally cancels the effect of the force generated by the fixing element), which in turn represents the braking torque (according to a known or experimentally derivable relationship).

[0133] Finally, by electronic processing means arranged in the acquisition system, the deformation is converted into a strain, which also finally represents the braking torque.

[0134] The system according to the invention described above has been properly modelled and dimensioned. The theoretical level of measurement accuracy has also been verified and proved to remain within acceptable limits for medium / high torque values. The behaviour at low braking torques has then been experimentally verified.

[0135] The system was then constructed and tested on a manually operated tangential bench with known values ​​of pressure and braking torque.

[0136] It is worth noting that the objects of the present invention are fully achieved by the method and system presented above, due to their functional and structural characteristics.

[0137] The detection device shown above is able to detect with good accuracy the force acting on the clamping interface between the brake caliper and the hub holder, which is directly dependent on the braking torque generated by the braking event.

[0138] Indeed, thanks to its structural and functional characteristics, such a detection device makes the measurement of the deformation or strain imparted by the forces acting locally on it substantially immune and independent of the axial clamping forces.

[0139] This is because the presence of the anti-friction element makes it possible to separate the load resulting from the tightening of the caliper fixing screws from the load imparted by the braking torque.

[0140] In other words, the concept of the detection device of the present invention utilizes the physical connection between the caliper and the hub holder, via a carrier element (see below in the description of the present invention) configured in the same device, freeing itself from interface friction forces.

[0141] At the same time, the above-mentioned detection device retains the advantages of a "washer detection device" and can in fact be advantageously and easily inserted between the brake caliper and the brake caliper bracket or hub holder using the fastening means already provided.

[0142] Similar advantages characterize systems and methods for measuring braking torque that use the aforementioned devices.

[0143] In fact, the braking torque measurement system and method achieves more accurate and reliable braking torque results.

[0144] This result is achieved due to the fact that such systems and methods are based on a chain of known deterministic relationships between quantities (braking torque depending on the force present at the fixed interface, which in turn depends on the deformation and / or strain detected by the device), where the physically detected quantity, i.e. the force applied to the hub holder by the brake caliper, is substantially dependent only on the force applied to the hub holder and is substantially independent of the clamping force, and the force applied to the hub holder by the brake caliper accurately represents the braking torque, while the clamping force, which is independent of the braking torque, causes disturbances in the measurement and is here avoided (while, not coincidentally, it is found in solutions proposed in the prior art).

[0145] Those skilled in the art can make many modifications and adaptations to the above-described embodiments or can substitute functionally equivalent elements to meet their foreseeable needs without departing from the scope of the appended claims. All features described above as belonging to one possible embodiment can be implemented independently of other described embodiments.

Claims

1. A detection device (1) for detecting a braking force acting on a hub holder or brake caliper support (20) by a brake caliper (10) during a braking event, the detection device comprising: the detection device (1) is configured to be attached to a fixed interface (i, ii) between a brake caliper (10) and a hub holder or brake caliper support (20) by means of clamping means (60) that exert a clamping force; The detection device (1) a low-friction body (2) formed as a washer or plate or bearing; a caliper-hub holder connecting element (3) connected to the low-friction body (2) and integral with the low-friction body (2), the caliper-hub holder connection element (3) is configured to be mechanically connected to both the brake caliper (10) and the hub holder or brake caliper support (20) in such a way as to provide a mechanical connection through which the braking force is at least partially released from the brake caliper (10) to the hub holder or brake caliper support (20) when the detection device (1) is provided at the fixed interface (i, ii); the caliper-hub-holder connecting element (3) is deformable, and the deformation and / or strain locally present in the caliper-hub-holder connecting element (3) depends on the force acting on the caliper-hub-holder connecting element (3); the low-friction body (2) decouples the clamping force from the braking force, and the deformation and / or strain present in the caliper-hub holder connection element (3) is representative of the braking force exerted by the brake caliper (10) on the hub holder or brake caliper support (20) by means of the caliper-hub holder connection element (3); The detection device (1) further comprises: at least one sensor element (4) operatively connected to said caliper-hub-holder connecting element (3) and configured to detect said deformation and / or strain present in said caliper-hub-holder connecting element (3) and to generate at least one electrical signal (S) indicative of said detected deformation and / or strain and a signal representative of said braking force; A detection device (1) having an electrical interface (5) connected to said at least one sensor element (4) for conducting and supplying said at least one generated electrical signal (S).

2. 2. The detection device (1) according to claim 1, wherein the low-friction body (2) comprises a plain bearing or an axial thrust bearing.

3. 2. The detection device (1) according to claim 1, wherein the low-friction body (2) comprises a layer of low-friction polymer material.

4. 2. The detection device (1) according to claim 1, wherein the low-friction body (2) comprises an element made of a metallic and / or ceramic and / or polymeric material, which is provided with a low-friction coefficient coating.

5. 5. The detection device (1) according to any one of claims 1 to 4, wherein the caliper-hub holder connecting element (3) comprises a bushing (32) and a disk-shaped annular plate (33).

6. 6. The detection device (1) according to claim 5, further comprising a shimming washer (7) configured to adapt the thickness of the detection device (1) to the dimensional and / or functional needs of the fixing interfaces (i, ii).

7. The low-friction body includes a low-friction element (2) interposed in contact with the disc-shaped annular plate (33) of the caliper-hub holder connecting element (3) and the shimming washer (7), With the detection device (1) attached to the fixed interfaces (i, ii), the annular disk plate (33) is adapted to be placed in intimate frictional contact with a surface of the brake caliper (10); 7. The detection device (1) according to claim 6, characterized in that the shimming washer (7) is adapted to be placed in intimate frictional contact with a surface of the hub holder or brake caliper support (20).

8. 8. The detection device (1) according to any one of claims 5 to 7, wherein the bushing (32) comprises a recess (30) configured to accommodate a portion of the fastening means (60) when the detection device (1) is attached to the fixing interface (i, ii).

9. The bushing (3) comprises at least one housing (31) configured to accommodate each at least one sensor element (3); 9. The detection device (1) according to one of claims 5 to 8, wherein the housing (31) is arranged at each detection position corresponding to a highly deformable bushing portion.

10. 10. The detection device (1) according to claim 5, wherein the bushing (3) is adapted to be coupled with a small clearance to both the brake caliper (10) side and the hub holder or brake caliper support (20) side when the detection device (1) is attached to the fixed interface (i, ii).

11. The detection device (1) according to any of the preceding claims, wherein the at least one sensor element (4) is a strain sensor (4).

12. 12. The detection device (1) according to claim 11, wherein the at least one sensor element (4) is an electrical strain gauge.

13. Detecting device (1) according to any of the preceding claims, wherein the caliper-hub-holder connecting element (3) and the low-friction body (2) are integrated into a single element.

14. Detecting device (1) according to claim 13, wherein the low-friction body comprises an anti-friction coating arranged on a disc-shaped base (33) of the caliper-hub-holder connecting element (3).

15. A detection device (1) as described in any one of claims 1 to 14, wherein the at least one sensor element (4) includes only one sensor element.

16. A detection device (1) as described in any one of claims 1 to 14, wherein the at least one sensor element (4) includes multiple sensor elements.

17. A detection device (1) as described in any one of claims 1 to 10, wherein the at least one sensor element (4) comprises three sensor elements.

18. A braking torque measurement system configured to determine a braking torque resulting from the operation of a braking system for a vehicle by detection performed at at least one fixed interface (i, ii) between a braking caliper (10) and a hub holder or brake caliper support (20). The braking torque measurement system includes: at least one detection device according to any one of claims 1 to 17, pressed at said at least one fixing interface (i, ii) between the brake caliper body (11) of said brake caliper (10) and said hub holder or brake caliper support (20); a clamping means (60) configured to clamp the brake caliper (10) and the hub holder or brake caliper support (20) together and to press the at least one detection device (1) between the brake caliper body (11) of the brake caliper (10) and the hub holder or brake caliper support (20); and electronic processing means operatively connected to said electrical interface (5) and adapted to receive said at least one electrical signal (S), 10. A braking torque measurement system, wherein the electronic processing means is configured to determine the braking torque based on the at least one electrical signal (S) indicative of a braking force acting on the at least one detection device.

19. The at least one fixed interface comprises a plurality of fixed interfaces (i, ii), said at least one detection device comprises a plurality of detection devices (D1, D2); each of the plurality of detection devices (D1, D2) is fixed to each of the plurality of fixing interfaces (i, ii); the at least one electrical signal (S) includes a plurality of electrical signals coming from each of the plurality of detection devices (D1, D2); 19. The braking torque measurement system of claim 18, wherein said electronic processing means is configured to determine said braking torque based on said plurality of electrical signals.

20. a first detection device (D1) of the first fixed interface (i) between a first caliper body portion and a first portion of the hub holder or brake caliper support; 20. The braking torque measurement system according to claim 19, further comprising the second detection device (D2) of the second fixed interface (ii) between a second caliper body portion and a second part of the hub holder or brake caliper support.

21. 21. A braking torque measurement system according to any of claims 18 to 20, wherein the electronic processing means comprises a control unit and / or processor configured to calculate the braking torque based on the at least one electrical signal (S) by means of one or more algorithms executed by one or more software programs.

22. the fastening means (60) comprises at least one screw (61, 62); 22. The braking torque measurement system according to any one of claims 18 to 21, wherein the at least one screw includes an anti-friction screw element located under the head of the screw.

23. 1. A brake caliper assembly for a vehicle braking system, comprising: A brake caliper (10); a hub holder or brake caliper support (20); At least one detection device (1) according to any one of claims 1 to 17, wherein the at least one detection device (1) is wedged between a brake caliper body (11) of the brake caliper (10) and the hub holder or brake caliper support (20) at at least one fixing interface (i, ii); and a clamping means (60) configured to clamp the brake caliper (10) and the hub holder or brake caliper support (20) together and to press the detection device (1) between the brake caliper body (11) of the brake caliper (10) and the hub holder or brake caliper support (20). The brake caliper assembly, wherein the brake caliper is a fixed caliper or a floating caliper.

24. a first detection device (D1) fixed between the brake caliper body (11) of the brake caliper (10) and said hub holder or brake caliper support (20) at a first fixing interface (i) by a first fixing bolt (61); 24. A brake caliper assembly according to claim 23, comprising a second detection device (D2) fixed between a brake caliper body (11) of said brake caliper (10) and said hub holder or brake caliper support (20) at a second fixing interface (ii) by means of a second fixing bolt (62).

25. 25. A braking system for a vehicle comprising a plurality of brake caliper assemblies according to any one of claims 23 to 24.

26. 1. A method for determining a braking torque resulting from the actuation of a vehicle brake system by detection performed at at least one fixed interface (i, ii) between a brake caliper (10) and a hub holder or brake caliper support (20), comprising: - an inserting step of at least one detection device (1) according to any one of claims 1 to 17 into said at least one fixing interface (i, ii), wherein said at least one detection device (1) is fixed to said at least one fixing interface (i, ii) between a brake caliper body (11) of said brake caliper (10) and said hub holder or brake caliper support (20) by means of a fastening means (60); a signal generating step of detecting, by said at least one detection device (1), a braking force exerted by said brake caliper (10) on said hub holder or brake caliper support (20) in the event of and due to a braking event, and generating at least one electrical signal (S) indicative of said detected braking force; a transmitting step of transmitting said at least one electrical signal (S) to electronic processing means; A method comprising a processing step of processing said at least one electrical signal (S) by said electronic processing means to determine said braking torque.

27. ​​The at least one detection device (1) has a plurality of detection devices (D1, D2), the at least one fixed interface comprises a plurality of fixed interfaces (i, ii); inserting each of said plurality of detection devices (D1, D2) into each of said plurality of fixed interfaces (i, ii); 27. The method of claim 26, wherein said processing step includes determining said braking torque based on a plurality of electrical signals (S) from said plurality of sensing devices (D1, D2).

28. wherein said processing step comprises a calculating step of calculating said braking torque by said electronic processing means by one or more algorithms executed by one or more software programs based on said at least one electrical signal (S), the calculating step calculates the braking torque according to a predetermined relationship between the braking torque and the braking force represented by a computerized model or look-up table accessible by the electronic processing means; 28. The method according to claim 26 or 27, wherein the predetermined relationship is determined through an experiment and / or characterization and / or calibration step performed after the at least one detection device (1) is placed and fixed at the respective fixation interface.

29. A braking system for a vehicle, comprising a braking torque measurement system described in any one of claims 18 to 22.

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