Device, system, and process for monitoring wear of friction material within a drum brake

Abstract

The present invention describes a device for monitoring wear of a friction material within a drum brake system, in addition to a system and process for monitoring wear of a friction material based on relative movement between an adjuster and a shaft, where this relative movement is mutually correlated to wear of the friction material. Specifically, a monitoring device is provided having a sensor assembly that recognizes relative movement between an adjuster and a shaft, and a processing unit that mutually correlates data from the relative movement to wear of the friction material. The present invention is in the fields of automobiles, in-vehicle electronics, brake systems, and sensing.

Description

Technical Field

[0001] The present invention describes a device for monitoring wear of a friction material within a drum brake, and more particularly, a device having a sensor assembly that recognizes relative motion correlated with wear of the friction material. The present invention is in the fields of automobiles, in-vehicle electronics, brake systems, and sensing.

Background Art

[0002] Many vehicles use what is known as a drum brake in their braking systems, which are particularly seen in large vehicles and on the rear axles of many city automobiles. A drum brake system generally consists of a brake drum that rotates integrally with the vehicle wheel, and when the brake is actuated, an actuator moves an internal mechanism that performs an outward movement from the center of the drum, thereby generating a force opposite to the rotational movement of the vehicle axle.

[0003] Examples of drum brake systems are shown in FIGS. 1 to 3. In these systems, when the driver presses the brake pedal, the brake chamber moves a slack adjuster (or brake ratchet) that rotates the S-camshaft. The S-cam then moves two brake shoes toward the brake drum via the inner pads. The brake shoes are equipped with a friction material, which is intended to generate a frictional force opposite to the rotational movement of the vehicle axle. This friction material is often known as brake lining.

[0004] When the driver actuates the brake system, of course, the friction material wears out. This wear can lead to malfunctions or failures within the brake system, thereby endangering the life of the driver and all persons on the road where the vehicle is moving. Therefore, the friction material needs to be replaced over time.

[0005] Many automobile manufacturers or brake manufacturers have set the average time for implementing the maintenance management of this. Furthermore, there are many cases where manual inspections of components are carried out by experts, which takes time and, in some cases, requires disassembling the entire system to check the condition (health) of the friction material.

[0006] As a result, several solutions have been developed to enable the use of in-vehicle electronic systems to monitor the wear of these friction materials in drum brake systems.

[0007] As an example, U.S. Patent Application No. 2011241866 shows one of these possible device configurations for monitoring a brake system. In U.S. Patent Application No. 2011241866, two rotating sensors arranged in parallel and operating integrally using the Hall effect are used. The first sensor is intended to read the clearance that occurs between the adjuster mechanism and the S-camshaft. The second sensor arranged in an additional structure to maintain a stationary state with respect to the shaft recognizes the entire braking stroke. Thereby, the data from both sensors are added and correlated with each other with respect to the total stroke of the adjuster. However, this solution requires two sensors that operate integrally to recognize the wear of the lining and further requires reading the complete stroke of the braking movement, which is not confused in the solution of the present invention.

[0008] U.S. Patent Application No. 2015377311 is similar to the above solution and shows a solution that uses a structure to house the sensor and maintain the sensor in a stationary state with respect to the S-camshaft of the drum brake. In U.S. Patent Application No. 2015377311, it is explained that the sensor is a potentiometer, and as a result, when the shaft moves due to the operation of the brake, the extending direction of the sensor is rotated, thereby enabling the measurement of angular displacement. Such an arrangement also similarly causes the sensor to read data related to the entire braking process.

[0009] U.S. Patent No. 5,253,735 shows one or two magnets attached to an S-camshaft and a stationary sensor configured to read the angular position of the magnets. The solution provided in this patent is similar to the solution mentioned above, because in this configuration the sensor has the role of reading not only the data related to lining wear, but also the entire braking operation process.

[0010] The expired patent PI9608527-4 shows a device for indicating wear on a brake lining. This solution uses a magnetically encoded disk divided into three sectors and a lid that houses sensors in various positions. The disk is attached to the shaft and the sensors remain stationary to read the code of the disk when the brake is actuated. Thus, this solution reads the entire braking operation process.

[0011] Document BR11 2013 024583-2 shows a more specific configuration for a structure that houses a sensor. This structure is a disk body that includes a protrusion, where this protrusion is aligned with a recess formed within another structure fixed to the S-camshaft. This structure facilitates the assembly of the equipment within the brake system. However, the sensor remains stationary with respect to a magnet that rotates along the S-camshaft.

[0012] In view of this, it can be noticed that none of the solutions mentioned above address the teachings of the present invention. The presented documents aim to monitor the wear of the friction material from a fixed structure, which cannot read the entire braking process and can only confirm the wear that occurs on the friction material.

[0013] In this sense, the aim here is to develop a solution that can identify the movement of the brake system directly related to the wear of the friction material and thereby provide efficiency and accuracy in monitoring the wear of the friction material.

[0014] Therefore, as can be inferred from the research literature, no literature has been found that predicts or suggests the teachings of the present invention. Therefore, the solution proposed here has novelty and inventive activity compared to the prior art.

Prior Art Documents

Patent Documents

[0015]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

[0016] Therefore, the present invention solves the problems of the prior art by monitoring the wear of the friction material based on the relative movement between the adjuster and the shaft so that as a result, the relative movement (relative displacement) with respect to the wear of the friction material is directly interrelated. For this purpose, the wear monitoring is carried out by a monitoring device having a sensor assembly that recognizes the relative movement and a processing unit that correlates the data of the relative movement with respect to the wear of the friction material. Therefore, the present invention promotes vehicle safety by realizing more accurate wear monitoring so as to contribute to the preventive maintenance and durability of the friction material and thus to the reliability of the operation of the brake system.

[0017] Accordingly, a first object of the present invention is to provide a device for monitoring the wear of a friction material within a drum brake system, where the brake system has an adjuster (4) for moving the shaft (5) of a brake drum (1), and the monitoring device is a sensor assembly for recognizing the relative movement between the adjuster (4) and the shaft (5), the sensor assembly being arranged within the brake system, the sensor assembly; and a processing unit (17) for communicating with the sensor assembly to obtain data on the relative movement between the adjuster (4) and the shaft (5), the data on the relative movement between the adjuster (4) and the shaft (5) being mutually associated with the wear of the friction material, the processing unit (17).

[0018] For a second object, the present invention provides a system for monitoring the wear of a friction material within a vehicle equipped with a drum brake system having an adjuster (4) for moving the shaft (5) of a brake drum (1), where the monitoring system has the friction material wear monitoring device defined above; and means for storing at least one movement data related to the wear of the friction material; where the processing unit (17) of the monitoring device mutually associates the data on the relative movement between the adjuster (4) and the shaft (5) with the above movement data related to the wear of the friction material.

[0019] For a third object, the present invention provides a process for monitoring the wear of a friction material within a drum brake system having an adjuster (4) for moving the shaft (5) of a brake drum (1) from the step of operating the drum brake system, where the monitoring process includes the step of recognizing the relative movement between the adjuster (4) and the shaft (5) by a sensor assembly; the step of obtaining data on the relative movement between the adjuster (4) and the shaft (5) by a processing unit (17) communicating with the sensor assembly; and the step of mutually associating the data on the relative movement between the adjuster (4) and the shaft (5) with the wear of the friction material by the processing unit (17).

[0020] These and other objects of the present invention will be readily apparent to those skilled in the art and will be described in detail below.

[0021] The following figures are provided to better define and clarify the content of this patent application.

Brief Description of the Drawings

[0022]

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Best Mode for Carrying Out the Invention

[0023] Examples of conventional drum brake systems are illustrated schematically in a series of FIGS. 1 through 3. In these systems, a brake drum (1) rotates integrally with a vehicle wheel, and when the brake chamber (2) is moved by a driver depressing a pedal, it moves a rod (3) fixed to a slack adjuster (4). The adjuster (4) is mechanically linked to the shaft (5) of the drum brake. An "S" - shaped cam (6) (often called an S - cam) is disposed at the opposite end of the shaft (5), and here, the S - cam (6) moves the brake shoe (7) toward the brake drum (1). The brake shoe (7) is equipped with a friction material (8), and the friction material (8) contacts the inner portion of the brake drum (1), thereby generating a frictional force opposite to the rotational movement of the vehicle wheel.

[0024] When the lining (8) wears due to friction occurring during the braking process, a clearance may appear between the friction material (8) and the drum (1). The automatic adjuster (4) has the function of correcting this slack between the brake lining (8) and the brake drum (1), thereby maintaining the distance between them constant and uniform, that is, adjusting the proximity of these components when the brake system returns to its initial position. As a result, the adjuster (4) makes it possible to improve braking safety because the lining (8) will be in an ideal position relative to the brake drum (1) to restart the braking process if necessary.

[0025] It should be noted that a brief introduction to the conventional schematization of the brake drum system does not limit the inventive concept proposed in this patent application. Furthermore, one solution known in the art for monitoring the wear of the friction material (8) of the brake system is to electronically recognize the complete actuation of the shaft (5) by the adjuster (4) using a sensor fixed to the shaft (5) to read the complete rotation of the shaft (5). Instead, the present invention is based on monitoring the wear of the friction material (8) by the relative movement between the adjuster (4) and the shaft (5).

[0026] Accordingly, a first object of the present invention is to provide a device for monitoring the wear of the friction material within a drum brake system, where the brake system has an adjuster (4) for moving the shaft (5) of the brake drum (1), and the monitoring device is a sensor assembly for recognizing the relative movement between the adjuster (4) and the shaft (5), the sensor assembly being arranged within the brake system, and a processing unit (17) for communicating with the sensor assembly to obtain data on the relative movement between the adjuster (4) and the shaft (5), the data on the relative movement between the adjuster (4) and the shaft (5) being mutually associated with the wear of the friction material.

[0027] Generally, the relative motion between an observer O and a component P is recognized by the observer O when the component P moves relative to the observer O. In the present invention, the relative motion of interest occurs as an angular change between an adjuster (4) and a shaft (5). The above relative motion occurs because the shaft (5) tries to rotate towards a favorable position inside the adjuster (4), whereby sufficient clearance is always maintained between the friction material (8) and the brake drum (1) in case the friction material wears due to the braking process. This rotation is realized by the internal mechanism of the automatic adjuster (4) when it senses that the friction material (8) has worn. In one embodiment, the relative angular motion between the adjuster (4) and the shaft (5) is proportional to the wear of the friction material (8). In this context, the present invention provides, in one embodiment, a sensor assembly capable of reading this motion generated between an S-cam shaft and an adjuster.

[0028] Accordingly, the processing unit (17) performs the above mutual association of the relative motion data between the adjuster (4) and the shaft (5) with respect to the motion data related to the wear of the friction material.

[0029] For this purpose, the monitoring device of the present invention has a sensor assembly arranged within the brake system for recognizing the relative motion between the adjuster (4) and the shaft (5). The relative motion is converted into relative motion data between the adjuster (4) and the shaft (5), and this data is readable by the processing unit (17). For the purposes of the present invention, the processing unit (17) can follow a set of predetermined instructions, can read motion data, and can perform the processing and mutual association of this data, and is any electronic component. In one embodiment, the processing unit (17) is a microcontroller or a microprocessor.

[0030] Therefore, the conversion of relative motion into data is carried out by a sensor assembly that generates relative motion data between the adjuster (4) and the shaft (5). In one embodiment, the sensor assembly generates relative motion data between the adjuster (4) and the shaft (5) based on an angular change related to the relative motion between the adjuster (4) and the shaft (5). In one embodiment, the data is generated from a linear variation related to the relative motion between the adjuster (4) and the shaft (5). In this last embodiment, linear motion is mechanically generated by the sensor assembly itself, converting the angular motion implemented by the relative motion between the adjuster (4) and the shaft (5).

[0031] In one embodiment, the above conversion is realized by a sensor assembly for sensing the relative motion between the adjuster (4) and the shaft (5). In addition, the above recognition is a physical perception realized by mechanical means, magnetic means, and / or electronic means.

[0032] In view of this, the sensor assembly has a first reactor associated with the shaft (5) and a second reactor associated with the brake system. Thereby, the second reactor recognizes the motion of the first reactor, and as a result, this motion corresponds to the relative motion between the adjuster (4) and the shaft (5).

[0033] For this purpose, the second reactor is arranged on one of the brake system components, such as the brake pedal, the brake chamber (2), the rod (3), the adjuster (4), etc., so that the second reactor recognizes the motion of the first reactor based on the changes related to the relative motion between the adjuster (4) and the shaft (5).

[0034] In one embodiment, the change associated with the relative movement between the adjuster (4) and the shaft (5) is an angular change between the first reactor and the second reactor. In one embodiment of the angular change associated with the relative movement between the adjuster (4) and the shaft (5), the second reactor is associated with the adjuster (4).

[0035] Accordingly, the sensor assembly recognizes the relative movement between the adjuster (4) and the shaft (5) and generates data of the relative movement described above. Thereby, the processing unit (17) communicates with the sensor assembly and receives the data of the relative movement between the adjuster (4) and the shaft (5), and thereby correlates this with the wear of the friction material.

[0036] Furthermore, the device for monitoring of the present invention has a structure (9) equipped with a housing (11) and a base (10) associated with the adjuster (4). In one embodiment, the structure (9) houses the processing unit (17). In another embodiment, the second reactor is a sensing module (14) arranged in the structure (9) by the housing (11).

[0037] In one embodiment, the housing (11) of the structure (9) is fixed to the base (10), and as a result, the second reactor is adjusted (or interlocked) to match the movement of the adjuster (4). In another embodiment, the housing (11) of the structure (9) has an interface between the first reactor and the second reactor. By doing so, the housing interface (11) provides a predetermined distance for separating the first reactor from the second reactor for the purpose of recognizing the relative movement between the adjuster (4) and the shaft (5). Accordingly, the present invention facilitates alleviating the possible axial differences associated with the relationship between the components of the device, because dimensional tolerances with large variations caused by the manufacturing process of the components in addition to the mechanical wear of such components are foreseen.

[0038] In addition, the first reactor is adjusted to match the movement of the shaft (5) arranged next to the housing interface (11) of the structure (9). In an embodiment where the first reactor is integrated with respect to the movement of the shaft (5) and the second reactor is integrated with respect to the movement of the adjuster (4), the change related to the relative movement between the adjuster (4) and the shaft (5) is the angle between the first reactor and the second reactor.

[0039] Alternatively, in one embodiment, the change related to the relative movement between the adjuster (4) and the shaft (5) is another angular change. In this embodiment, the first reactor is one sector of the shaft (5), and the second reactor is an arm connected to the adjuster (4) and arranged on the sector of the shaft (5), where the arm recognizes the movement of the sector of the shaft (5), and this movement is related to the relative movement between the adjuster (4) and the shaft (5).

[0040] For a second object, the present invention provides a system for monitoring the wear of a friction material in a vehicle equipped with a drum brake system having an adjuster (4) for moving the shaft (5) of the brake drum (1), where the system for monitoring has a device for monitoring the wear of the friction material as defined above, and means for storing at least one movement data related to the wear of the friction material, where the processing unit (17) of the monitoring device correlates the data of the relative movement between the adjuster (4) and the shaft (5) with the above movement data related to the wear of the friction material.

[0041] In one embodiment, the means for storing motion data related to the wear of the friction material assembles the history of the vehicle driver's brake system operation for checking the state of the friction material (4). Additionally, a system for monitoring can be mounted within any S-cam drum brake system as a kit for monitoring, measuring, and identifying the lining wear (8), thereby avoiding accidents by recognizing wear with higher accuracy. In one embodiment, the system of the present invention is mounted within the drum brake during their manufacture. In another embodiment, the above system is mounted within a pre-manufactured drum brake.

[0042] By doing so, when the brake is actuated, the sensor assembly can monitor the relative movement between the adjuster (4) and the shaft (5). This relative movement is caused by the wear of the friction material (8) as already shown, and the adjuster (4) has a tendency to correct the existing slack between the friction material (8) and the brake drum (1). This arrangement of the device for monitoring according to the present invention by detecting the relative movement between the adjuster (4) and the shaft (5) prevents the sensor assembly from capturing any interference caused by the slack between the mechanical components of the brake system, because the change in position between the shaft (5) and the adjuster (4) means that there is wear on the friction material (8).

[0043] In one embodiment, the communication between the processing unit (17) and the sensor assembly is wireless communication, where the processing unit (17) is arranged on the chassis of the vehicle and the sensor assembly is arranged on the brake system. In another embodiment, the communication between the processing unit (17) and the sensor assembly is wired communication.

[0044] In another embodiment, the processing unit (17) communicates with a device that makes friction material wear data available to the user. This data can be made available to the vehicle driver via a display mounted in the vehicle or via a smartphone. This data can also be made available to a remote server.

[0045] Furthermore, a device for monitoring communicates with a remote station, where the remote station receives motion data related to the wear of the friction material. In one embodiment, the remote station manages a fleet of vehicles, and as a result, the present invention improves the reliability of the fleet of vehicles by monitoring the wear of the respective linings (8) of the vehicles.

[0046] For a third object, the present invention provides a process for monitoring the wear of a friction material in a drum brake system having an adjuster (4) for moving the shaft (5) of the brake drum (1) from the step of operating the drum brake system, where the process for monitoring includes the steps of recognizing, by a sensor assembly, the relative movement between the adjuster (4) and the shaft (5); obtaining, by a processing unit (17) communicating with the sensor assembly, data on the relative movement between the adjuster (4) and the shaft (5); and correlating, by the processing unit (17), the data on the relative movement between the adjuster (4) and the shaft (5) with the wear of the friction material.

[0047] In one embodiment, the above process is implemented using the device for monitoring already described. In one embodiment, the above process follows the flowchart shown in FIG. 4.

[0048] Therefore, the braking system is actuated by the brake pedal, which in turn moves the rod (3) that moves the adjuster (4), and further moves the shaft (5). Naturally, the friction material (8) wears out, creating a slack between the friction material (8) and the brake drum (1), where the adjuster (4) compensates for the slack.

[0049] As a result, the braking system realizes the relative movement between the adjuster (4) and the shaft (5). Therefore, the process of the present invention has a step of recognizing the relative movement between the adjuster (4) and the shaft (5) by the sensor assembly.

[0050] Finally, the process of the present invention has a step of converting the relative movement between the adjuster (4) and the shaft (5) into data of the relative movement between the adjuster (4) and the shaft (5) by the sensor assembly, where the data of the relative movement is converted based on the change in the movement of the first reactor recognized by the second reactor. In one embodiment, the change in movement is an angular change. In addition, the second reactor is associated with the braking system, while the first reactor is associated with the shaft (5).

[0051] The process then performs the acquisition of the relative movement data between the adjuster (4) and the shaft (5) by the processing unit (17). The processing unit (17) performs the mutual association of the relative movement data between the adjuster (4) and the shaft (5) with respect to the wear of the friction material (8) using the above relative movement data.

[0052] By doing so, the process of the present invention realizes a more accurate mutual association with respect to the continuous wear of the friction material (8). In one embodiment, the above mutual association is the mutual association of the relative movement data between the adjuster (4) and the shaft (5) with respect to the movement data related to the wear of the friction material.

[0053] Based on this, wear data becomes available to the user, and as a result, the user can access the monitoring of the friction material (8). This data can be made available in a vehicle-mounted display (e.g., in-vehicle computer), the user's smartphone, a remote server, or a combination of these alternatives.

[0054] The present invention can be applied to any drum brake system and can be adapted to fit disk brakes regardless of the type of vehicle, such as city cars, passenger transport vehicles, freight cars, road implements, etc.

[0055] The examples shown herein are merely intended to illustrate one of the many ways of implementing the present invention without limiting the scope of the present invention.

[0056] "Example 1" The device of the present invention was developed to be applied in a drum brake system. A conventional drum brake system is schematized in a series of FIGS. 1 to 3.

[0057] The device for monitoring in this example implements the process shown in the flowchart of FIG. 4. For this purpose, the device of this example has a sensor assembly and a processing unit (17) arranged in the brake system by a structure (9) having a base (10) screwed to an adjuster (4) through a hole (91), as shown in FIG. 5a.

[0058] FIG. 5b shows the housing (11) directly attached to the shaft (5) with the base (10) removed. FIG. 5c shows a front view of the housing (11) covered by a lid that closes the housing (11) by screwing to facilitate maintenance management of the device.

[0059] Figure 5d shows a rear view of the housing (11), highlighting the head (12) that enables direct connection of the housing (11) to the shaft (12). Here, the head (12) is fitted into a U-shaped protrusion formed on the surface of the housing (11). The U-shaped geometry enables central positioning between the head (12) and the sensors inside the housing (11), and furthermore, since it has a fitting that functions as a drawer, it prevents the housing (11) from moving in a direction away from the head (12). Additionally, this fitting enables relative angular movement between the head (12) adjusted to fit the shaft (5) and the housing (11) adjusted to fit the structure (9), and the structure (9) is further fixed to the frame of the adjuster (4). As a result, the head (12) has an end portion threaded to be connected to the shaft (5).

[0060] In this way, the head (12) defines a first reactor adjusted to match the movement of the shaft (5), as can be seen in Figure 5e. Additionally, the housing (11) has a relief (112) at its peripheral edge, and the relief (112) is fitted into the base (10), preventing the movement of the housing (11) integrated with the shaft (5), and as a result, maintaining the state where the housing (11) is adjusted to fit the adjuster (4). Furthermore, the relief (112) prevents improper assembly at the pre-arranged position because the relief is non-uniformly arranged and configured at the peripheral edge of the housing (11).

[0061] Furthermore, the housing (11) has an interface (115) between the first reactor and a second reactor housed inside the housing (11), thereby facilitating the spacing between the first reactor and the second reactor to be as defined. For example, the second reactor is a sensing module (14), a sensor separated from the first reactor by a certain distance by the interface (115) together with the head (12), and as a result, the sensor comes to recognize the movement of the first reactor.

[0062] Therefore, the device of the present example includes the concept of the present invention by equipping a sensor assembly that recognizes the relative movement between the adjuster (4) and the shaft (5), as indicated by the various positions of the sensing module (14) relative to the shaft (5). The sensing module (14) is associated with the adjuster (4). Therefore, the relative movement between the adjuster (4) and the shaft (5) is converted into the above relative movement data (data related to the relative movement) based on the angular change between the sensing module (14) and the magnet (13) connected to the head (12).

[0063] Finally, the processing unit (17) receives the above relative movement data and correlates this data with the movement data related to wear. For example, the processing unit (17) is also housed within the housing (11).

[0064] "Example 2" As shown in FIGS. 6a to 6c, the moving device of the present example has a structure (9) fixed to the adjuster (4) by a support (92) surrounding the adjuster (4) so as to conform to the shape of the adjuster (4). Further, the support (92) is brought into close contact with the adjuster (4).

[0065] In the arrangement configuration of the components of the device of the present invention, the structure (9) is a single body or, as shown in FIG. 6d, is divided into two parts, namely the base (10) and the housing (11). Therefore, the structure (9), which is a single body or divided into two parts, is suitable for fixing together with a plurality of adjusters (4).

[0066] Therefore, the base (10) is screwed onto the support (92) by three fixing elements (91). Thereby, the housing (11) is fitted inside the base (10) and locked by the protruding portion (112) arranged on its peripheral portion in a state of being in contact with the inside of the housing (11).

[0067] To recognize the relative movement between the adjuster (4) and the shaft (5), the sensor assembly of this embodiment is formed by a first reactor which is a magnet (13) and a second reactor which is a sensor (14) that utilizes the Hall effect principle to read the angular change resulting from the relative movement between the shaft (5) and the adjuster (4). Therefore, the relative movement between the adjuster (4) and the shaft (5) is converted into relative movement data.

[0068] Furthermore, in FIG. 6d, the housing (11) houses the sensor (14). Thereby, the sensor (14) is adjusted to fit the housing (11) fixed to the structure (9). Here, the sensor (14) is arranged and configured at the movable end of the housing (11) inside the housing (11). As a result, the sensor (14) can move axially inside the housing (11), but the protrusion of the housing (11) prevents the rotation of the sensor (14) with respect to the adjuster (4) and prevents it from being assembled out of the pre-arranged position because the protrusions are not uniformly arranged.

[0069] Therefore, the housing (11) receives the sensor (14) so that the sensor (14) is placed within a predetermined distance range with respect to the magnet (13) fixed to the tip of the shaft (5) of the S-cam (6) as can be seen in FIG. 6e. Further, the housing portion (12) fixes the magnet (13) to the shaft (5). Here, the magnet (13) is placed so as to contact the movable end of the housing (11) and can rotate freely with respect to the sensor (14) fixed to the adjuster (4). From this, the thickness of the movable end of the housing (11) enables the adaptation of the predetermined distance between the magnet (13) and the sensor (14).

[0070] Furthermore, FIG. 6f shows the housing (11), and when the sensor (14) is received within the housing (11), it can move axially within the housing (11) by the movable end of the housing (11), thereby compensating for the axial difference during device assembly and mainly maintaining a predetermined distance between the sensor (14) and the magnet (13) for the purpose of accurately reading the relative movement between the automatic adjuster (4) and the shaft (5). FIG. 6f further shows a sealing ring adjacent to the movable end of the housing (11), such that the housing portion (12) is sealed.

[0071] FIG. 6g shows the housing (11) connected to the base (10) so as to form the structure (9). Further, the base (10) is fixed to the adjuster (4) through fixing elements arranged and configured at the peripheral edge of the base (10), thereby eliminating the need for the support (92). A lid is fixed to the housing (11) to close the base (10).

[0072] FIG. 6h shows the housing (11) removed from the base (10), where a spring adjusts the axial distance between the sensor (14) and the magnet (13), thereby eliminating the need for adaptation components such as washers. Insulation is performed using at least a resin covering the sensor (14) to receive the sensor (14) inside the housing (11) with the battery and the embedded circuit of the sensor (14) connected. In addition, the housing (11) has an opening that allows the battery to be replaced.

[0073] In addition, the embedded circuit of the sensor (14) has a wireless module that enables wireless communication for communicating with a control unit fixed to the chassis or for supplying power and receiving signals via a cable. Thereby, the sensor (14) transmits data on the relative movement between the adjuster (4) and the shaft (5) to the processing unit (17).

[0074] In this example, the processing unit (17) is attached to the surface opposite to the surface that houses the sensor (14). As a result, it becomes possible to perform wear monitoring in a manner mounted on the vehicle itself, and as a result, this data becomes available to the driver and also to the server or remote user. The processing unit (17) is equipped with in-vehicle intelligence that executes one algorithm. The above algorithm correlates the data read by the sensor (14) with the data already stored. The data already stored is the relative angle change between the adjuster (4) and the shaft (5), which is mutually correlated with the wear data. Further, the wear data is data regarding the wear of the brake drum (1), the wear of the lining (8) having surplus material, and the wear of the roller with extra measurement adjacent to the shaft (5).

[0075] "Example 3" The monitoring device of this example is connected to the drum brake system as illustrated in FIG. 7a. The structure (9) is directly connected to the automatic adjuster (4), and as a result, when the automatic adjuster (4) is displaced by the rod (3) of the brake chamber (2), the structure (9) follows its rotational movement. FIG. 7b shows a separate view of the automatic adjuster (4) having the structure (9) to which the automatic adjuster (4) is fixed, and further, the processing unit (17).

[0076] As can be seen in FIG. 7c, the structure (9) is equipped with a base (10) and a housing (11). The base (10) has the role of fixing the structural assembly (9) to the automatic adjuster (4). The above base (10) has tabs for fixing the structure (9) to the automatic adjuster (4), where this fixing can be performed by permanent or non-permanent fixing elements.

[0077] In this example, the base (10) has two heights, a first height for fixing together with the adjuster (4) and a second height for fixing together with the housing (11), where the second height has a radius smaller than the radius of the first height. At the second height, protrusions for fixing together with the housing (11) are formed, here along the outer periphery of the second height. The above protrusions are fitted into cavities formed in the outer periphery of the housing (11), and as a result, both of them will geometrically fit together.

[0078] In FIG. 7d showing an exploded view with further details of the device, it can be seen that the sensor (14) is connected to the housing (11). The housing (11) has a surface for receiving the sensor (14), and as a result, the sensor (14) will be placed within a predetermined distance range with respect to the magnet (13) fixed to the tip of the shaft (5) of the S-cam (6).

[0079] In the configuration of this example, the magnet (13) is fixed to the tip of the shaft (5) through the plastic housing part (12), and the plastic housing part (12) further has the function of moving the magnetic field in a direction away from the metal material of the shaft, thereby preventing this magnetic field from affecting the collected data. By doing so, the magnet (13) can rotate freely with respect to the sensor (14) fixed to the cover (11). Therefore, in this configuration, the sensor (14) can read the rotational movement performed by the shaft (5) with respect to the automatic adjuster (4) itself, because the sensor (14) moves integrally with the automatic adjuster (4).

[0080] Furthermore, in FIG. 7d, it can be seen that the processing unit (17) is attached to the surface opposite to the surface that houses the sensor (14). This enables wear monitoring to be carried out in a form mounted on the vehicle itself, and as a result, this data becomes available to the driver and also to the server or remote users.

[0081] "Example 4" Furthermore, a concept test and proof were performed using the Hall effect sensor of AS5600. Since other sensor models can surely be used to implement the concept proposed in the present invention, the examples given here do not limit the scope of the present invention.

[0082] Based on this, FIGS. 8 and 9 show, respectively, an example of the angular change of the magnet (13) with respect to the sensor (14) and the recommended distance range between the magnet (13) and the sensor (14), as obtained from the data sheet of the components of AS5600 to clarify its operation. This distance range is considered when assembling the sensor (14) with respect to the housing (11) of the structure (9). In this example, the interface (115) between the sensor and the magnet is a partition of the housing (11).

[0083] In these tests, it was possible to obtain different parameters regarding the percentage of lining wear (8) and the relative angular movement between the adjuster (4) and the shaft (5) from the collected data, as shown in FIG. 10. Furthermore, in FIG. 11, it is possible to confirm the test results of lining wear (%) with respect to the lining thickness (mm).

[0084] A person skilled in the art will recognize the information presented herein and will be able to reproduce the present invention in the presented embodiments as well as in other variations and alternatives encompassed by the following claims.

Claims

1. A device for monitoring wear of a friction material in a drum brake system, wherein the brake system has an adjuster (4) for moving a shaft (5) of the brake drum (1), and the monitoring device has a) a sensor assembly for sensing relative movement between the adjuster (4) and the shaft (5), the sensor assembly being disposed within the brake system; and b) a processing unit (17) in communication with the sensor assembly for acquiring data regarding the relative movement between the adjuster (4) and the shaft (5), the data regarding the relative movement between the adjuster (4) and the shaft (5) being mutually associated with the wear of the friction material. Processing unit (17) A device for monitoring, characterized by comprising the above.

2. The relative movement between the adjuster (4) and the shaft (5) is an angular change, and the processing unit (17) performs the mutual association of the relative movement data between the adjuster (4) and the shaft (5) with the movement data related to the wear of the friction material. The device for monitoring according to claim 1, characterized by this.

3. The sensor assembly has a) a first reactor associated with the shaft (5); and b) a second reactor associated with the brake system, the second reactor sensing the movement of the first reactor, whereby this movement corresponds to the relative movement between the adjuster (4) and the shaft (5). Second reactor A device for monitoring according to claim 1, characterized by comprising the above.

4. The device for monitoring according to claim 3, characterized in that the second reactor is associated with the adjuster (4).

5. The second reactor has a sensing module (14) disposed within a structure (9), the structure (9) having a base (10) associated with the adjuster (4) and a housing (11) for accommodating the sensing module (14). The device for monitoring according to claim 3, characterized by this.

6. The housing (11) of the structure (9) is fixed to the base (10) and has an interface between the first reactor and the second reactor. The device for monitoring according to claim 5, characterized by this. Claim 7 The device for monitoring according to claim 6, wherein the first reactor is linked to the movement of the shaft arranged adjacent to the interface of the housing (11) of the structure (9). Claim 8 A system for monitoring wear of a friction material in a vehicle comprising a drum brake system having an adjuster (4) for moving a shaft (5) of the brake drum (1), the monitoring system comprising: a) a device for monitoring wear of a friction material as defined in claim 1; b) means for storing at least one movement data related to the wear of the friction material; and a monitoring system, wherein a processing unit (17) of the monitoring device converts data of the relative movement between the adjuster (4) and the shaft (5) into the movement data related to the wear of the friction material. Claim 9 The monitoring system according to claim 8, wherein the monitoring device communicates with a remote station, and the remote station receives movement data related to the wear of the friction material. Claim 10 A process for monitoring wear of a friction material in a drum brake system having an adjuster (4) for moving a shaft (5) of the brake drum (1) from the step of operating the drum brake system, the monitoring process comprising: a) recognizing a relative movement between the adjuster (4) and the shaft (5) by a sensor assembly arranged in the brake system; b) obtaining data of the relative movement between the adjuster (4) and the shaft (5) by a processing unit (17) communicating with the sensor assembly; c) correlating the data of the relative movement between the adjuster (4) and the shaft (5) with the friction of the friction material by the processing unit (17). and a monitoring process characterized by including the above steps. Claim 11 The monitoring process according to claim 10, wherein the mutual correlation is a mutual correlation between the relative movement data between the adjuster (4) and the shaft (5) and the movement data related to the wear of the friction material. Claim 12 The process for monitoring includes a step of converting, by the sensor assembly, the relative movement between the adjuster (4) and the shaft (5) into data regarding the relative movement between the adjuster (4) and the shaft (5), the relative movement being converted based on a change in the movement of a first reactor associated with the shaft (5), the change being recognized by a second reactor, the process for monitoring according to claim 10.

13. The process for monitoring according to claim 12, characterized in that the second reactor is associated with the braking system.

14. The data of the relative movement between the adjuster (4) and the shaft (5) is associated with the continuous friction of the friction material, the process for monitoring according to claim 10.

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