Brake pad and brake particle capture nozzle

Abstract

Brake pad comprising a back plate (3) and a pad (2) supported on said back plate (3), said pad (2) comprising a friction surface (21) suitable for coming into contact with a rotor (11) and a brake particle collection channel (4) opening on said friction surface (21), said collection channel (4) being in fluid communication with: - a duct (41) leading to an inlet (42) at a distance from said friction surface, said duct (41) having a first diameter (D1) over a main portion (41.1) of its extension; and - a suction hole (5) suitable for being connected to a vacuum source, said pad (1) comprising blocking means (6) configured to prevent a body (8) having a size greater than a limit value (Dm) from entering said duct (41) via said inlet (42), said limit value (Dm) being less than or equal to 90% of said first diameter (D1).

Description

Technical Field

[0001] The technical field of this disclosure is pollution-free braking systems intended for use in machines comprising a rotating element to be braked, such as road or rail vehicles, or in structures comprising a rotating element, such as wind turbines. In such braking systems, during friction braking, particles and dust are generated and emitted due to wear of the brake pads relative to the rotating element. This rotating element is, for example, a vehicle wheel or a disc driven by a rotating element. It is known that when these particles are dispersed into the surrounding environment, they are harmful to human health and the environment.

[0002] Furthermore, the rise of electric drive systems in motor vehicles has increased the need to address particulate matter and dust generated by friction braking systems. Therefore, it is necessary to capture these particles and dust before they are released into the surrounding environment.

[0003] More specifically, this disclosure relates to a brake pad and a braking system including the brake pad. Background Technology

[0004] In braking systems, Example 10 is known as shown in Figure 1 In this process, the common practice is to use a brake pad 1 to slow down the rotation of the rotating element 11 through contact. As mentioned above, this frictional action generates a large number of particles.

[0005] Patent document FR3087238, shown in Figure 2 The text describes a liner 1 having a particle suction groove 4 with a radial inlet 42 located on one side of the liner. Figure 2 (upper part), so as to collect particles more effectively than grooves that open only on the friction surface 21. Another solution ( Figure 2 The lower part (of the design) involves constructing inlet 42 as an orifice. The advantage of this design is that it maintains a consistent negative pressure level and flow rate throughout the entire wear life of the liner. In contrast, when inlet 42 is a groove, its intake area decreases as the friction liner 21 wears. The size of the orifice forming the air inlet is designed to ensure sufficient negative pressure level and flow rate.

[0006] During operation, especially when the opening is constructed as an orifice, inlet 42 may be partially or completely blocked by foreign objects such as small stones or mud. This may render the system inoperable or reduce its efficiency: requiring increased suction power to capture the same amount of particles.

[0007] Therefore, this disclosure aims to overcome at least in part the disadvantages of the prior art described above.

[0008] In particular, one object of this disclosure is to provide a braking liner that ensures pumping efficiency is maintained throughout its service life. Summary of the Invention

[0009] The aforementioned objective is achieved in particular by a brake pad comprising a backing plate and a liner supported on the backing plate, the liner including a friction surface adapted to contact a rotor and a brake particle collection groove opening on the friction surface, the collection groove being in fluid communication with: a conduit leading to an inlet at a location remote from the friction surface, the conduit having a first diameter over a major portion of its extension; and a suction port adapted to connect to a vacuum source; the liner including a blocking device configured to prevent a body of a size greater than a certain limit from entering the conduit via the inlet, the limit being less than or equal to 90% of the first diameter.

[0010] The solution disclosed herein provides protection beyond the simple geometry of the inlet in a particularly effective manner. In fact, the inventors have discovered that while foreign objects roughly the same size as the inlet are blocked by the inlet, objects slightly smaller than the inlet size are the most problematic. Objects significantly smaller than the inlet size do not cause blockage: they will be drawn in and transported along with the collected particles via a channel to the system outlet or to a downstream processing unit, such as a filter, without interfering with system operation. However, experiments have shown that objects slightly smaller than the first diameter (whose size is greater than 90% of the pipe size) have a high probability of becoming stuck in the inlet or pipe due to wedging or similar phenomena, completely or partially blocking airflow and thus reducing the efficiency of the collection process: if the suction inlet is blocked, the suction power must be increased to maintain the target negative pressure and a sufficient collection rate. Furthermore, such objects intruding into the system can also damage its components (pipes, filters, etc.). Therefore, the proposed solution improves the reliability of the particle collection system.

[0011] The subject may be of any shape, although it is depicted as spherical in the accompanying drawings for illustration and clarity. Therefore, the terms “size,” “measurement,” and “diameter” should be understood to refer to the maximum dimension of the subject, regardless of its shape.

[0012] The bushings according to this disclosure can be used, for example, in road vehicles (cars, buses, heavy vehicles, etc.) or rail vehicles (trains, trams, subways, etc.), as well as in rotor-based stationary machines, such as wind turbines or industrial machines.

[0013] According to some examples, such a scheme can be implemented in a braking system comprising two bushings positioned opposite each other on opposite sides of a rotor, such that each bushing contacts the rotor (brake disc). Each bushing may include a friction surface, in which at least one collection groove may be formed, the friction surface being configured to contact the rotor.

[0014] The liner can be positioned such that the friction surface of the liner includes at least one flat portion substantially perpendicular to the rotor's axis of rotation, which can be contacted against.

[0015] In other examples, the liner and its pads can be arranged in different ways for use in drum braking systems: the friction surface of the pads is cylindrical and radially abuts against the inner surface of the drum.

[0016] The liner is formed of a friction material, which may include materials commonly referred to as "Ferodo". The friction material may be selected from the group consisting of organic materials, metallic materials, semi-metallic materials, or ceramic materials.

[0017] Although such pads are typically used in pairs, the remainder of the specification will focus on individual pads. Two identical pads according to this disclosure may be used, or at least one pad according to this disclosure may be used in a braking system comprising two or more pads.

[0018] The pipe may have a cross-section of a first diameter over most of its extension, meaning that it has a constant diameter for more than 50% of its length, and preferably more than 80% of its length. It is understood that if the pipe's cross-section is not circular, the pipe may have a "first dimension" that is equally crucial for passing (or not passing) mud or rocks. For example, if the cross-section is rectangular, the "first dimension" is the distance between the two longer sides of the rectangle. In the case of a pipe with an elliptical cross-section, the first dimension is the length of the minor axis of the elliptical cross-section. In other examples, the pipe 41 may be polygonal or oblong. Generally, depending on the shape of the cross-section of the pipe 41, the "first diameter" may correspond to the inscribed circle, equivalent cross-section, or equivalent hydraulic diameter of the pipe 41.

[0019] Therefore, even when the pipe does not have a circular cross-section, this disclosure uses the term "first diameter" as a convenient abbreviation.

[0020] The features described in the following paragraphs may be implemented optionally, independently of each other or in combination: According to some examples, the limit is less than or equal to 70% of the first diameter. Thus, (at least) all parts with dimensions greater than 70% of the diameter of the main part of the pipe are blocked.

[0021] According to some examples, the limit is less than or equal to 32% of the first diameter, and preferably less than or equal to 16% of the first diameter.

[0022] According to some examples, the first diameter is between 1 mm and 6 mm, and the first diameter is preferably about 4 mm.

[0023] According to some examples, the blocking device is attached to the liner, or is a component integrally formed with the liner or the backing plate.

[0024] According to some examples, the blocking device includes a blocking element positioned facing the entrance and at a distance from the entrance equal to the limit value.

[0025] According to some examples, the blocking element is integrally formed with the backplate, and preferably, the blocking element is a U-shaped extension of the backplate. This shape of the blocking element, among other advantages, can limit the accumulation of mud at the inlet, since dried mud can prevent or hinder suction.

[0026] According to some examples, the barrier device includes a grille arranged around the entrance.

[0027] According to some examples, the grille may be dome-shaped. This shape has the advantage of minimizing resistance to air intake, thus achieving a satisfactory airflow rate within the slot. Alternatively, the grille may be flat, or have any other shape capable of covering the inlet.

[0028] According to some examples, the grille is integrally formed with an insert having a through-channel and fitted into the pipe. The channel functions to provide a fluid connection between the pipe (or directly a groove) and the outside of the liner. This insert-based approach allows for the modification of existing liners that did not originally possess such a barrier device, based on the barrier device disclosed herein.

[0029] According to some examples, the inlet extends through an opening on the outer surface of the liner, and the grille is fitted onto this outer surface to cover the inlet. Preferably, the grille is welded to the outer surface.

[0030] The outer surface may be the surface of the backplate or the liner, or may extend across both the liner and the backplate of the liner block. The outer surface may be the surface of the backplate on the side opposite the mounting surface of the receiving liner. The conduit may then pass through both the liner and the backplate. According to some examples, the outer surface may be a side surface, such as the lateral side or radial (inner or outer) surface of the liner and / or the backplate.

[0031] According to some examples, the inlet has a second diameter that is smaller than the first diameter of the pipe, particularly by at least 10%, and the inlet constitutes all or part of the blocking device. For consistency with the definition of the first diameter mentioned above, the term "second diameter" may be used as a shorthand to refer to the critical dimension of the non-circular cross-section of the inlet.

[0032] According to some examples, the conduit, in addition to a main portion defining a first diameter, also includes a portion with a reduced cross-section, preferably tapered, extending from the main portion to the inlet. Such a conduit with a first and a second diameter can be obtained by drilling with a tapered drill bit and stopping the drill bit's progress before the drill head has completely penetrated the material. According to some examples, this second diameter can be provided on an insert, which may have a drilled channel and be inserted into the conduit. This solution enables the application of blocking device schemes to existing liners.

[0033] According to another aspect, this disclosure relates to a brake particle trapping nozzle comprising: a collection tank configured to be positioned facing a brake rotor; a conduit in fluid communication with the collection tank and including an inlet, the conduit having a first diameter over a major portion of its extension; and a suction orifice configured to be connected to a vacuum source; the nozzle including a blocking device configured to prevent a body of a size greater than a certain limit from entering the conduit via the inlet, the limit being less than or equal to 90% of the first diameter.

[0034] According to some examples, the limit is less than or equal to 70% of the first diameter.

[0035] According to some examples, the limit is less than or equal to 32% of the first diameter, and preferably less than or equal to 16% of the first diameter.

[0036] According to some examples, the first diameter is between 1 mm and 6 mm, and the first diameter is preferably about 4 mm.

[0037] According to some examples, the blocking device includes a blocking element positioned facing the entrance and at a distance from the entrance equal to the limit value.

[0038] According to some examples, the barrier device includes a grille arranged around the entrance.

[0039] According to some examples, the grille is integrally formed with an insert having a through channel and fitted into a pipe.

[0040] According to some examples, the inlet has a second diameter that is smaller than the first diameter of the pipe, in particular by at least 10%, and the inlet constitutes all or part of the blocking device.

[0041] According to some examples, in addition to the main portion defining the first diameter, the pipe also includes a portion with a reduced cross-section, preferably tapered, that extends from the main portion to the inlet.

[0042] According to another aspect, this disclosure relates to a braking system comprising a rotor and: a pair of brake pads as described above and / or one or more particle trapping nozzles as described above; the braking system further comprising a vacuum source in fluid communication with a suction orifice of a slot in each brake pad and / or each trapping nozzle.

[0043] This invention also provides other technical advantages. In particular, the proposed solution is easy to implement, can be implemented on existing brake pads or existing braking systems, is cost-effective, and its shape and volume are adapted to the highly constrained environment of the braking system. Furthermore, limiting the entry of large foreign objects into the pneumatic circuit helps prevent potential impacts on the filter located in the pneumatic circuit, thereby reducing mechanical stress on the filter; therefore, a less robust filter can be selected, or a filter made of more flexible or cheaper materials. Attached Figure Description

[0044] Other features, details, and advantages will become apparent from reading the following detailed description and analyzing the accompanying drawings, in which: [ Figure 1 This shows a schematic representation of a disc brake.

[0045] [ Figure 2 The diagram shows a schematic representation of two examples of brake pads known in the prior art, each pad including a collection groove and a pipe having an inlet in the form of a groove or hole.

[0046] [ Figure 3 The image shows a cross-sectional view of an example brake pad, in which grooves, pipes, suction holes, and the openings of the grooves on the friction surface are visible.

[0047] [ Figure 4 An example of a blocking device including a U-shaped blocking element is shown.

[0048] [ Figure 5 This image shows an example of a blocking device that includes an L-shaped blocking element.

[0049] [ Figure 6 An example of a blocking device including a grille integrated with an insert is shown.

[0050] [ Figure 7 An example of a blocking device including an attached grille is shown.

[0051] [ Figure 8 This illustrates an example of a blocking device that includes a section with a reduced cross-section at one end of a pipe.

[0052] [ Figure 9 An example of a variation is shown, wherein a groove is formed on a nozzle, which is separate from the friction surface and includes an inlet to which a blocking device according to this disclosure can be applied.

[0053] [ Figure 10 [Showing] Figure 9 Another example of the variation is that the slot has multiple inlets.

[0054] [ Figure 11 Showing Figure 10 A cross-sectional view of a similar example, including a blocking device at each entrance. Detailed Implementation

[0055] The accompanying drawings and the following description contain specific details in most cases. Therefore, they can be used not only to better understand this disclosure, but also, where appropriate, to help define it.

[0056] In the figures, the same reference numerals denote the same or similar elements. For the sake of brevity, only elements that help to understand the embodiments are shown in the figures, and are described in detail below.

[0057] In the following description, when referring to absolute position qualifiers (such as the terms "front," "rear," "upper," "lower," "left," "right," etc.) or relative position qualifiers (such as the terms "above," "below," "upper," "lower," etc.), or directional qualifiers (such as "horizontal," "vertical," etc.), unless otherwise specified, these refer to the common names for the braking system in its normal operating position. Unless otherwise specified, the terms "axial" and "radial" are considered to be relative to the axis of rotation of the braked rotor. Furthermore, the term "basic" should be interpreted as indicating that the obtained result is as accurate as the known methods used to measure it.

[0058] Figures 1 to 3 An example of a prior art braking system is shown. This is achieved by replacing at least one of the brake pads with... Figures 4 to 8 Examples of applying the proposed solution are shown in any of the figures. Unless otherwise stated, the application of the solution to the block is... Figures 1 to 3 The characteristics of the liner that remain unchanged are applied to the liner according to this disclosure.

[0059] More specifically, Figure 1 An example of a braking system 10 known in the prior art is shown, which includes a rotor 11, which in this example is a brake disc, with a brake caliper 12 mounted above the brake disc. The brake caliper is equipped with two brake pads 1 (partially visible here), located on one side of two annular surfaces of the brake disc.

[0060] The example of braking system 10 illustrates one exemplary application of the proposed solution, but is not limiting. In fact, this solution can be applied to any braking system that utilizes the friction of brake pads, such as drum brakes. Furthermore, although the type of braking system shown by way of example is common in the automotive field, braking systems can also be equipped in other fields, such as other types of road or rail vehicles, rotating industrial machinery, or stationary structures such as wind turbines.

[0061] Figure 2 An example of two brake pads 1 is shown, each brake pad being equipped with a pad 2 attached to a backing plate 3. Each brake pad 1 includes a pad 2 adapted to contact the rotor 11. The pad 2 specifically includes a friction surface 21, which, when mounted on... Figure 1 When used in a braking system of the type shown, the friction surface is at least partially located in a plane perpendicular to the rotation axis A of the rotor 11.

[0062] The liner 2 may be attached to the backplate 3, together forming the brake pad 1. The backplate 3 may have a plate-like shape, such as a metal plate. According to some examples, the backplate 3 may be larger than the liner 2, such that it extends beyond the sides of the liner (23, 24, 25, 25).

[0063] Optionally, the backplate 3 may serve as an interface between the pad 1 and other components of the braking system 10, such as sensors or mounting elements for the brake caliper 12 or linear drive mechanism. The pad 2 functions to contact the rotor to be braked, while the backplate 3 does not contact the rotor during braking. The pad 2 is typically attached to the backplate 3 via a mounting surface opposite the friction surface 21.

[0064] During braking, the friction surface 21 of the bushing 1 is pressed against the rotor 11. This contact generates a frictional force, which is applied substantially tangentially to the direction of rotation of the rotor 11, and... Figure 2 The arrows are schematically shown in the diagram. These forces cause the lining to wear down gradually. As mentioned above, this generates particles from the friction material of the lining. These particles are typically polluting and toxic. At least some of these particles are collected by collection grooves 4 located in one or more linings 2.

[0065] Tank 4 typically includes a pipe 41 that terminates at an inlet 42, where the inlet 42 is located at... Figure 2 Clearly visible in the middle. The groove 4 also includes a suction hole 5 (visible in...). Figure 3 The function of pipe 41 is to allow air to enter through its inlet 42 and be drawn in by the suction port 5.

[0066] The slot 4 also has an opening 45 on the friction surface 21, which is different from the inlet 42 and the suction port 5. This opening 45 is configured to be closed by the annular surface of the rotor 11 that contacts the friction surface 21 (especially during braking). An airflow is subsequently generated by a vacuum source, which draws air through the suction port 5, forcing the air into the slot 4 via the conduit 41, as the opening 45 remains closed by the rotor. This creates a negative pressure at the portion of the rotor facing the opening 45. Braking particles enter the slot 4, specifically through this opening 45, and are collected. The opening 45 may be provided along at least a portion of the length of the slot, which may ultimately form a groove in the liner 2. The slot may be arranged such that when in contact with the rotor at the friction surface 21, the annular surface of the rotor closes the opening of the slot 4.

[0067] Figure 2 The difference between the two examples shown lies in the geometry of the conduit 41 and its inlet 42: one (in the upper part of the figure) is implemented as a groove that opens on the friction surface 21, the disadvantage of which is that it shrinks as the liner wears; the other example (in the lower part of the figure) is an improvement on the first example, in which the inlet 42 is in the form of a hole that does not open on the friction surface 21, thereby forming a conduit in the liner 2.

[0068] Examples of groove 4, opening 45, inlet 42, pipe 41, and suction port 5 are particularly shown in Figure 3 As can be seen in the image. In this example, inlet 42 is located on the lateral side of the liner 2, while suction hole 5 is a through hole in the mounting surface for attaching the liner 2 to the back plate 3, with its opening located on the opposite side of the back plate 3 opposite to the liner 2. Inlet 42 and suction hole 5 are in fluid communication via groove 4, which in this example are located at opposite ends of groove 4.

[0069] Figure 4 An example of this disclosure is shown schematically.

[0070] Pipe 41 and inlet 42 in this example have the same diameter, referred to as "first diameter D1". In this example, the pipe and inlet are circular, but their cross-sections can have any shape, such as polygonal, elliptical, or oblong, and / or differ from each other. Pipe 41 shown here has a cross-section with constant dimensions along its entire length. In other examples, pipe 41 may have a cross-section with varying dimensions or shape. Pipe 41 extends in a straight line here, but other examples can be considered where the pipe has curved sections or changes in direction. However, it is advantageous that the pipe has a constant cross-section and extends substantially in a straight line, at least for a major portion 41.1 of its length. This helps to avoid pressure loss and airflow turbulence.

[0071] The opening of the pipe 41 may be located in the surface of the back plate 3, or on the side of the liner 2 other than the friction surface 21, or at the interface between the back plate 3 and the liner 2. The side of the liner other than the friction surface 21 may be, for example, the transverse side 25, 26, or the radial inner side 23 or the radial outer side 24 of the liner 2.

[0072] In this example, the conduit 41 passes through the liner 2 in which a groove 4 is formed, and then through the back plate 3 to which the liner is attached. The liner 2 is attached to the back plate at the mounting surface, and the inlet 42 of the conduit 41 is located in the outer surface 43 of the back plate 3, which is located on the side of the back plate opposite to the mounting surface.

[0073] According to some examples, the liner 2 may include a plurality of inlets 41 and optionally a plurality of suction holes 5. According to some examples, the trough 4 may include one or more inlets 41 and / or one or more suction holes 5. According to some examples, the conduits 41 and suction holes 5 may each be located at a position not at the end of the trough 4. In addition, the liner 2 may include one or more collection troughs 4. In addition, the liner 1 may also include one or more liner 2s. Typically, the trough 4 extends from the conduits 41 to the suction holes 5, each located at one end of the trough 4. However, it is conceivable that the suction holes 5 are located, for example, in the middle of the trough 4, with two conduits 41 arranged at both ends of the trough 4, or any other configuration that ultimately allows for airflow through the trough 4 from at least one conduit 41 to at least one suction hole 5.

[0074] According to some examples, groove 4 extends in a straight line in a single direction, which is substantially perpendicular to the direction of friction (e.g., ...). Figure 2 (As indicated by the middle arrow). In practice, this configuration allows for maximizing the coverage of the surface area involved in friction, thereby effectively collecting particles emitted during friction. In other examples, the groove 4 may also include non-linear portions and / or portions not perpendicular to the frictional force. For example, the groove may be angled, curved, or have a change in direction, and may have more than two ends, particularly several branches extending in different directions. For example, the groove may consist of several straight portions connected by angles.

[0075] In the presence of multiple slots 4, each slot may have its own opening 45 in the friction surface 21, each opening for collecting particles. The opening 45 allows braking particles to enter the slot 4 and be collected by airflow. Subsequently, the particles are carried away by a vacuum source located downstream of the braking system 10, such as into a processing unit, such as a filter.

[0076] The opening of the suction port 5 can be located in the back plate 3 of the liner 1. For example, the suction port 5 can form a channel extending from the mounting surface of the liner 2 and through the back plate 3. The suction port can be in direct or indirect fluid communication with a vacuum source.

[0077] The vacuum source can be a suction device, such as a fan or turbine. The suction port 5 can be directly connected to the vacuum source, for example via a sealed fluid connection 51 (e.g., a pipe or hose). The suction port 5 of the slot 4 can be indirectly connected to the vacuum source, for example via an element other than a simple fluid connection (e.g., a filter), which is inserted, for example, between the suction port 5 of the slot 4 and the vacuum source. Alternatively, the suction port 5 of the first slot 4 can be in fluid communication with the pipe 41 of the second slot 4 in the same brake pad or another brake pad.

[0078] According to this disclosure, the liner 1 includes a blocking device 6, an example of which is shown in Figures 4 to 8 The blocking device 6 is configured to prevent the body 8, with a size greater than a limit Dm (even partially), from entering the pipe 41 via the inlet 42, where the limit Dm is less than or equal to 90% of the first diameter. Thus, even if the size of the body 8 is smaller than the first diameter of the pipe, it cannot enter the pipe 41 through the inlet 42 if its size exceeds the value Dm. Therefore, the particle collection system can be protected and its efficiency maintained at a satisfactory level without modifying the geometry of the pipe 41, whose dimensions are typically designed to allow for a sufficient level of negative pressure in the channel 4. In fact, manufacturing a smaller pipe (e.g., a circular pipe with a diameter Dm) would reduce suction efficiency and impair the particle collection process.

[0079] The limit value Dm is less than the first diameter D1 of pipe 41. According to some examples, the value Dm is less than or equal to 70% of the first diameter of pipe 41. In other examples, the value Dm is less than or equal to 32% of the first diameter, or even less than or equal to 16% of the first diameter of pipe 41. The minimum internal dimension of the pipe can be between 1 mm and 6 mm, and is preferably about 4 mm.

[0080] according to Figure 4 In the example shown, the blocking device 6 includes a blocking element 61 positioned facing the inlet 42 and at a distance equal to a limit Dm from the inlet. Specifically, the blocking element 61 has a blocking surface 46 arranged to face the outer surface 43. Because the blocking surface 46 is spaced apart from the outer surface 43 by a distance Dm, all objects with a size greater than or equal to Dm will be blocked before reaching the inlet 42. The blocking surface 46 may be substantially parallel to the outer surface 43. The blocking element 61 is arranged to extend and cover the entire air inlet area defined by the inlet 42. Thus, if the blocking element 61 extends from one side of the inlet 42, it extends at least to the opposite side of the inlet 42, and even beyond. The length of the extended blocking element 61 is at least equal to the first diameter of the conduit 41. The width L of the blocking element 61 is at least equal to the first diameter of the conduit 41. Figure 4 In a variant not shown, the blocking element 61 only partially covers the inlet 42, as partial coverage is sufficient to prevent unwanted bodies 8 from entering the pipe 41.

[0081] The blocking element 61 can be integrally formed with the back plate 3, such as Figure 4 and Figure 5 As shown. In Figure 4 In the example, the blocking element 61 is a U-shaped extension of the back plate 3. This shape is obtained, for example, by bending a protrusion integrally formed with the back plate. Figure 5 In the example shown, the blocking element 61 is L-shaped. Generally speaking, regardless of the shape of the blocking element 61, the blocking element 61 includes a portion that is positioned directly facing the entrance 42.

[0082] The advantage of the blocking element 61 is that it allows air to pass through a gap with a width equal to Dm, which extends a relatively long length compared to its width. In effect, a slit-like gap with a width of Dm is formed between the outer surface 43 and the blocking surface 46, extending along most of the circumference of the inlet 42. This allows suction to be maintained even when the body 8 is wedged between the blocking surface 46 and the outer surface 43, because the body only blocks a small portion of the total surface area of ​​the gap.

[0083] exist Figure 5 In the middle, the pipe 41 passes through the liner 2 and leads to a surface of the liner, which may be a radial inner surface or a radial outer surface, or an upstream transverse surface or a downstream transverse surface.

[0084] Figure 6 Another example of a blocking device is shown, comprising a grille 62 arranged around an inlet 42. The grille 62 has opening regions 64, which are preferably regularly distributed across the surface of the grille 62. The grille 62 may, for example, have a dome-shaped or hemispherical shape, as shown in the example. This is used to maximize airflow. Other shapes are also possible. The opening regions 64 may all have the same shape and size, or may be as follows: Figure 6 and Figure 7 The examples show variations in size and shape.

[0085] Regardless of the shape of the opening area 64 or the shape of the grille, the minimum size of the opening area 64 is equal to the value Dm. In this way, due to the size of the opening area 64, any body larger than the value Dm is blocked by the grille 62 and cannot reach the entrance 42.

[0086] exist Figure 6In the example shown, the grille 62 is integrally formed with the insert 63, which is inserted into a cavity 66 created to widen the conduit 41. The insert 63 has a through channel 65; this channel may have a cross-section with the same first diameter as the conduit 41 so as not to alter the suction performance of the conduit 41. In other words, the channel 65 forms a continuation of the conduit 41. The cross-section of the channel 65 may be constant for at least a major portion of its length. The channel 65 may be formed by drilling into the insert 63 or by any other means known to those skilled in the art. In this example, the opening of the inlet 42 is not located in the outer surface 43 of the liner, but at the bottom of the cavity 66, forming a shoulder. The insert 63 is inserted until it abuts against this shoulder at the bottom of the cavity 66, i.e., the inlet 42 of the conduit 41, which then communicates fluidly with the channel 65. The assembly of the insert 63 with the cavity 66 can generally be achieved by an interference fit or by any other means known to those skilled in the art. According to some examples, the insert is a shaping insert used when sintering the liner 2 onto the backing plate 3.

[0087] The grille 62 may be fitted onto the insert 63 at an end opposite to the end abutting the bottom of the cavity 66. The grille 62 may then be welded to the insert 63 or attached by any other means known to those skilled in the art. The grille 62 may also be integrally formed with the insert, and the opening region 64 may be obtained, for example, by appropriate machining operations on the material of the insert 63.

[0088] In other examples, when the blocking device 6 does not include the insert 63, the grille 62 can be directly mounted on the outer surface 43 where the opening of the pipe 41 is located. The grille is then installed to cover the inlet 42 in the outer surface 43 (or, if the pipe opening is located therein, to cover any other surface of the liner). For example, as... Figure 7 As shown, the grille is mounted directly on the outer surface 43 of the back plate. According to some examples, the grille 62 is welded to the outer surface 43 or attached by any means known to those skilled in the art. The grille 62 may also be integrally formed with some other components of the back plate 3 or the bushing 1.

[0089] In other examples, the blocking device 6 may include a plate or plug in addition to or in place of the grille 62, the plate or plug being pierced with one or more through holes serving as opening regions 64.

[0090] exist Figure 8In the example shown, inlet 42 has a second diameter smaller than the first diameter of pipe 41; here, inlet 42 itself forms a blocking device 6 by virtue of its geometry. For example, the second diameter may be at least 10% smaller than the first diameter. In this case, a body 8 larger than the value Dm will be blocked by the restricted inlet 42 and will not be able to reach pipe 41. This example can be combined with another example of a blocking device, such as including a grille 62 surrounding the restricted inlet 42 and / or a blocking element 61 positioned towards the restricted inlet.

[0091] In addition to a main portion 41.1 having a first diameter, the conduit 41 includes a portion 44 with a reduced cross-section (“reduced portion”) extending from the main portion 41.1 to the inlet 42 and having a second diameter smaller than the first diameter. The reduced portion 44 may be tapered, with its diameter decreasing linearly from the main portion 41.1 to the inlet 42. Alternatively, the reduced portion 44 may be provided with a diameter reduction to form a curve (e.g., an arc). Depending on its shape, the reduced portion 44 may be obtained, for example, by drilling with a tapered drill bit or by machining with a ball end mill. The reduced portion 44 may be configured such that its diameter continuously decreases from the main portion 41.1 to the inlet 42, without any portion having a constant diameter. In practice, the presence of a plateau portion with a constant diameter may create an area where a body slightly smaller than the dimension Dm of the inlet 42 may become trapped and block the reduced portion 44.

[0092] According to one variation, the collection tank 4, which is in fluid communication with the vacuum source, can be arranged spaced apart from the friction liner 2. In practice, the tank can be separate from the liner, or even separate from the liner block. In other examples, the tank can be integral with the liner block but separate from the friction surface 21.

[0093] according to Figure 9 and Figure 10 The example shown can be a replacement or supplement to the aforementioned liner, where slot 4 can be provided on the trapping nozzle 100, which is positioned spaced apart from the friction surface 21. The example shown has only one slot, but multiple slots can be provided on a single nozzle. Similarly, multiple trapping nozzles can be provided for a single rotor; in particular, two nozzles can be positioned opposite each other on opposite sides of the brake rotor. The nozzle or multiple nozzles can be attached to a brake caliper bracket or brake caliper.

[0094] The collection groove 4 of the nozzle 100 includes an opening 45, which is configured to be positioned facing an annular surface of the rotor 10. This annular surface is typically the surface that contacts the friction lining of the bushing during braking. Thus, the opening 45 of the groove 4 in the nozzle 100 performs the function of capturing braking particles.

[0095] Similar to the example described above where the groove 4 is formed in the friction surface 21 of the liner 2, the collection groove 4 of the nozzle 100 is in fluid communication with the following: a conduit 41, which is different from the opening 45 and includes an inlet 42, the conduit having a first diameter D1 on the main portion 41.1 of its extension; and a suction port 5, which is different from the opening 45 and is configured to connect to a vacuum source.

[0096] The nozzle is thus configured to generate an airflow from inlet 42, through pipe 41 and slot 4. This airflow draws particles through opening 45 toward suction port 5, which is connected to a vacuum source via fluid connector 51.

[0097] According to some examples, similar to grooves formed in friction surfaces, the grooves may have multiple suction holes 5 and / or multiple inlets 42. Figure 10 An example of this is shown, illustrating a pair of nozzles 100, each facing one of the annular surfaces on either side of a brake disc (not shown); each nozzle includes two inlets 42 and a suction port 5, which is connected to a vacuum source via a fluid connection 51. In this example, the suction port 5 is located approximately in the middle of the nozzle, while the two inlets 42 (and thus two conduits 41) are arranged at two opposite ends of the nozzle.

[0098] The capturing nozzle 100 also includes a blocking device 6 configured to prevent a body 8 with a size greater than a limit Dm from entering the pipe 41 via the inlet 42 of the nozzle 100, wherein the limit Dm is less than or equal to 90% of a first diameter D1. The blocking device 6 may conform to the examples described above and... Figures 4 to 8 The example shown. Based on the adoption Figures 4 to 8 Which of the blocking devices 6 shown can provide the same technical benefits for the nozzle as for the aforementioned liner?

[0099] Although these various examples have been described individually, they can be combined with each other according to this disclosure. In particular, although not shown, examples of the blocking device 6 including blocking element 61 and / or grille 62 and / or reduced portion 44 are conceivable.

Claims

1. A brake pad (1) comprising a back plate (3) and a liner (2) supported on the back plate (3), the liner (2) comprising a friction surface (21) adapted to contact a rotor (11) and a brake particle collection groove (4) opening in the friction surface (21), the collection groove (4) being in fluid communication with the following portion: - A conduit (41) leading to an inlet (42) at a distance from the friction surface (21), the conduit (41) having a first diameter (D1) on the main portion (41.1) of its extension; and - Suction port (5), which is adapted to be connected to a vacuum source, The liner (1) includes a blocking device (6) configured to prevent a body (8) with a size greater than a limit (Dm) from entering the pipe (41) via the inlet (42), the limit (Dm) being less than or equal to 90% of the first diameter (D1).

2. The liner (1) according to claim 1, characterized in that, The limit is less than or equal to 70% of the first diameter.

3. The liner (1) according to claim 1 or 2, characterized in that, The limit is less than or equal to 32% of the first diameter, and preferably less than or equal to 16% of the first diameter.

4. The liner (1) according to any one of claims 1 to 3, characterized in that, The first diameter is between 1 mm and 6 mm, and the first diameter is preferably about 4 mm.

5. The liner (1) according to any one of claims 1 to 4, characterized in that, The blocking device (6) is attached to the liner (2) or is an integral part of the liner (2) or the back plate (3).

6. The liner (1) according to any one of claims 1 to 5, characterized in that, The blocking device (6) includes a blocking element (61) positioned facing the entrance (42) and at a distance from the entrance equal to the limit value (Dm).

7. The liner (1) according to the preceding claim, characterized in that, The blocking element (61) is integrally formed with the back plate (3), and preferably, the blocking element (61) is a U-shaped extension of the back plate (3).

8. The liner (1) according to any one of claims 1 to 7, characterized in that, The blocking device (6) includes a grille (62) arranged around the entrance (42).

9. The liner (1) according to the preceding claim, characterized in that, The grille (62) is integrally formed with an insert (63) having a through channel (65) and fitted into the pipe (41).

10. The liner (1) according to claim 8, characterized in that, The inlet (42) penetrates the opening of the outer surface (43) of the liner (1), and the grille (62) is fitted onto the outer surface (43) to cover the inlet (42), and the grille (62) is preferably welded to the outer surface (43).

11. The liner (1) according to any one of claims 1 to 10, characterized in that, The inlet (42) has a second diameter that is smaller than the first diameter of the pipe (41), in particular at least 10% smaller, and the inlet (42) constitutes all or part of the blocking device.

12. The liner (1) according to any one of claims 1 to 11, characterized in that, In addition to the main portion (41.1) defining the first diameter (D1), the conduit (41) also includes a portion (44) with a reduced cross-section, preferably tapered, which extends from the main portion (41.1) to the inlet (42).

13. A brake particle collecting nozzle (100), comprising: - A collection trough (4) is configured to be positioned facing the brake rotor (10); - A conduit (41) in fluid communication with the collection tank (4) and including an inlet (42), the conduit (41) having a first diameter (D1) on the main portion (41.1) of its extension; and - Suction port (5), which is configured to connect to a vacuum source. The nozzle (100) includes a blocking device (6) configured to prevent a body (8) with a size greater than a limit (Dm) from entering the pipe (41) via the inlet (42), the limit (Dm) being less than or equal to 90% of the first diameter (D1).

14. The particle collecting nozzle (100) according to claim 13, characterized in that, The limit (Dm) is less than or equal to 70% of the first diameter.

15. The particle collecting nozzle (100) according to claim 13 or 14, characterized in that, The limit is less than or equal to 32% of the first diameter, and preferably less than or equal to 16% of the first diameter.

16. The particle collecting nozzle (100) according to any one of claims 13 to 15, characterized in that, The first diameter is between 1 mm and 6 mm, and the first diameter is preferably about 4 mm.

17. The particle collecting nozzle (100) according to any one of claims 13 to 16, characterized in that, The blocking device (6) includes a blocking element (61) positioned facing the entrance (42) and at a distance from the entrance equal to the limit value (Dm).

18. The particle collecting nozzle (100) according to any one of claims 13 to 17, characterized in that, The blocking device (6) includes a grille (62) arranged around the entrance (42).

19. The particle collecting nozzle (100) according to any one of claims 13 to 18, characterized in that, The grille (62) is integrally formed with an insert (63) having a through channel (65) and fitted into the pipe (41).

20. The particle collecting nozzle (100) according to any one of claims 13 to 19, characterized in that, The inlet (42) has a second diameter that is smaller than the first diameter of the pipe (41), in particular at least 10% smaller, and the inlet (42) constitutes all or part of the blocking device.

21. The particle collecting nozzle (100) according to any one of claims 13 to 20, characterized in that, In addition to the main portion (41.1) defining the first diameter (D1), the conduit (41) also includes a portion (44) with a reduced cross-section, preferably tapered, which extends from the main portion (41.1) to the inlet (42).

22. A braking system (10) comprising a rotor (11) and: - A pair of brake pads (1) according to any one of claims 1 to 12; - and / or one or more particle trapping nozzles (100) according to any one of claims 13 to 21. The braking system (10) also includes a vacuum source in fluid communication with a suction port (5) of a slot (4) of each liner (1) and / or each trap nozzle (100).

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