Brake particle trapping system

Abstract

The invention relates to a system (20) for trapping brake particles emitted by a disc brake (2), the trapping system (20) comprising: particle-suctioning means (22, 24, 26) which are able to adopt a first state, in which the suctioning means (22, 24, 26) produce a first level of suction, and a second state, in which the suctioning means produce a second level of suction that is stronger than the first level of suction; and a control unit (30) which regulates the state of the suctioning means (22, 24, 26), the control unit (30) being configured to switch the suctioning means (22, 24, 26) from the first state to the second state when a signal (34) for the rotational speed of the disc (4) of the brake (2), received by the control unit (30), indicates that the disc (4), in an acceleration phase, has exceeded a threshold rotational speed.

Description

Description Title: BRAKE PARTICLE CAPTURE SYSTEM Technical field

[0001] This disclosure relates to the field of vehicle braking devices (automobiles or railways) or industrial braking devices. The context relates in particular to the environmental protection aspects by the suction of braking particles emitted by friction brakes, in particular disc brakes. Prior art

[0002] Document FR 3 057 040 A1 describes a disc brake lining equipped with a collection groove and a through orifice, fluidically connected to suction means. This lining makes it possible to efficiently suck up brake dust over the entire radial height of the lining. The suction means comprise a turbine generating a vacuum which sucks up the dust to direct it towards a collection filter.

[0003] Documents DE 198 46 887 A1 and DE 196 43 869 A1 illustrate two examples of control of suction means in which maximum suction is controlled during braking.

[0004] Document FR 3 088 395 A1 introduces the concept of suction compensation based on the filling level of the collection filter: in order to guarantee satisfactory suction throughout the life of the filter, the suction power can increase if necessary.

[0005] Another example is given in document CH 687 013 A5 which distinguishes between braking carried out while the vehicle is moving at low speed (< 20 km / h) and during which no suction is carried out, and braking carried out while the vehicle is moving at higher speed (> 20 km / h), during which the suction of brake dust is controlled.

[0006] Thus, existing systems systematically recommend activating suction during braking phases and deactivating suction after braking phases. However, as explained below, the inventors of the present disclosure have highlighted the fact that, surprisingly, braking particles could be emitted outside of braking phases. Summary

[0007] The present disclosure thus provides a particle capture system and related methods, which significantly increase the quantity of brake particles recovered.

[0008] There is provided a system for capturing braking particles emitted by a disc brake, the capturing system comprising: particle suction means, capable of adopting a first state, in which the suction means produce a first suction level, and a second state, in which the suction means produce a second suction level, higher than the first suction level; and a control unit regulating the state of the suction means, the system being remarkable in that the control unit is configured to switch the suction means from the first state to the second state when a brake disc rotation speed signal, received by the control unit, indicates that the disc, in the acceleration phase, has exceeded a first threshold rotation speed.

[0009] The inventors have demonstrated that particles can be emitted even outside of braking phases, and in particular during acceleration beyond a certain speed. Without wishing to be bound by theory, the emission of these particles has been attributed to a centrifugal acceleration on the surface of the disc ejecting particles which would remain there after the suction which takes place during a previous braking. Aerodynamic disturbances (turbulence) generated by the rotation of the disc and / or by the movement of the vehicle, can also come into play.

[0010] The inventors thus identified a peak in particle emissions during acceleration. It would appear that after these particles have been evacuated, the emission level drops again, probably due to the exhaustion of these particles.

[0011] Thus, by ordering an increased suction level at the time of the emissions peak, particle capture is substantially increased. We observe a 10-point increase in the number of particles captured compared to a system that does not increase its suction level at the time of the peak. The threshold rotation speed value at which suction is triggered may depend on the design of the parts, the materials involved, the type of vehicle, etc. It can be defined empirically for each vehicle or industrial machine, or be obtained by modeling or extrapolation after experiments.

[0012] The intended application includes disc brakes for motor vehicles or railways or industrial disc brakes. In this type of brake, one or more linings come into contact with one or more discs. It is understood that the particle capture system of the present disclosure is also capable of capturing particles from other types of brake, particularly drum brakes.

[0013] By "suction level" is meant a measurable physical parameter related to suction, this physical parameter being able to be the depression (absolute value of a negative pressure), the suction flow velocity or the suction flow rate. Thus, a higher level suction has a greater depression, a greater flow velocity and / or a greater suction flow rate. In the present disclosure, one level is considered higher than another when the measurable parameters of the two levels differ strictly, for example by a relative value of at least 1% or at least 5% or at least 10% of one of these parameters. In certain examples according to the present disclosure, this difference can be increased to 100%, one of the levels being double the other, or one of the levels being an absence of suction.

[0014] It is understood that the system of the present disclosure contains at least two distinct suction levels outside of braking phases. It may thus comprise more than two levels, and the suction means may be switched into these more than two levels depending on the rotational speed of the disc. In the same way that a rotational speed threshold, during acceleration, switches the suction means from a first level to a second level, a another threshold may be provided to switch from the second level to a third suction level, higher or lower than the second level, and higher or lower than the first level. The suction levels outside the braking phases may be different from the suction level applied during braking. Other parameters, such as for example the in situ detection of emitted particles, by a detector, may be taken into account for switching from one suction level to another suction level.

[0015] The "suction means" comprise one or more elements configured to create a negative pressure flow in the vicinity of the interface between the disc and the friction lining. The documents cited above give examples of structures for generating this negative pressure flow. These include, in particular, a caliper cover, a suction nozzle, a lining with a groove and a through-orifice. The vacuum source may consist of a turbine. The suction level may be adjusted by acting directly on the vacuum source, for example the intensity supplying the turbine to increase or decrease its rotation speed. Alternatively or in addition, the suction level may be adjusted indirectly: a valve may be interposed between the vacuum source and the disc / lining interface, the valve totally or partially filtering the suction power of the vacuum source.

[0016] By "control unit" we mean a hardware and / or software element dedicated to controlling the capture system or integrated into one of the main controllers of the vehicle (ICAN, ECU, EMS, etc.) or the industrial machine.

[0017] The "disc rotation speed signal" can come from a sensor directly measuring the rotation speed of the disc (tachometer, rev counter, optical, magnetic, electrical sensor, ESP, ABS, etc.). Alternatively, the rotation speed of the disc can be measured indirectly: for a vehicle, it can be measured on the crankshaft; for an industrial machine, it can be estimated by measuring the power delivered.

[0018] The trigger speed threshold is a threshold detected during the acceleration phase, i.e. when the rotational speed of the disc is increasing, the brake remaining inactivated. It should be noted that the present disclosure relates to normal use of a device and that the activation of the brake is seen here as incompatible with acceleration.

[0019] The acceleration phase may or may not follow a braking operation.

[0020] During a braking operation, the suction means may adopt a "zero" state in which the non-zero suction level may correspond to the second level, and / or may correspond to the maximum suction that the suction means can produce, and / or may be lower than the second level, and / or may be higher than the second level.

[0021] According to an advantageous embodiment, the first suction level corresponds to an absence of suction. Thus, the first suction level can correspond to a deactivated vacuum source (for example a stopped turbine or a closed valve in a pipe fluidically connecting a turbine to the brake). A first non-suction level makes it possible to increase the system's contribution to protecting the environment, by consuming less energy.

[0022] According to an advantageous embodiment, the control unit is configured to maintain the suction means in the second state, following the switching, for a duration of between 5 and 30 seconds, preferably between 10 and 15 seconds, then, after this duration, to switch the suction means back to the first state. Thus, the suction can be controlled independently of the rotation speed of the disk, since only a few seconds are sufficient to guarantee ideal suction, even if the rotation speed of the disk were to remain in the vicinity of the first threshold speed.

[0023] According to an advantageous embodiment, the control unit is configured to switch the suction means from the second state to the first state, if the following two conditions are met: a disk rotation speed signal, received by the control unit, indicates that the disk, in the deceleration phase, goes below a second threshold rotation speed, possibly equal to the first threshold rotation speed; and the brake is inactive, the switching of the suction means from the second state to the first state potentially being carried out after a time delay of 10 to 15 seconds during which these two conditions are maintained true. Indeed, following acceleration, if the disk decelerates, the phenomena leading to the emission of particles may disappear and it would not be appropriate to maintain the second suction level since particles would no longer be ejected and energy would therefore be wasted.When the brake is fitted to a vehicle, the disc speed can be obtained from the tachometer, the disc rotation speed being proportional to that of the vehicle.

[0024] According to an advantageous embodiment, the control unit is configured to maintain the suction means in the second state as soon as the disk rotation speed signal indicates that the disk is rotating at a speed greater than a third threshold rotation speed, preferably equal to the first and / or the second threshold rotation speed. Indeed, certain conditions may lead to choosing to maintain the second suction level when a speed threshold is exceeded. This operating mode may be an alternative mode to the aforementioned activation duration, or it may be selectable by a user, the control unit being able to be provided with a dedicated interface allowing this choice to be made.

[0025] The invention also relates to a motor or railway vehicle comprising: a disc brake; a system for capturing braking particles emitted by the disc brake; and means for detecting the speed of the vehicle, the capture system comprising: particle suction means, capable of adopting a first state, in which the suction means produce a first suction level, and a second state, in which the suction means produce a second suction level, higher than the first suction level; and a control unit regulating the state of the suction means, the vehicle being remarkable in that the control unit is configured to switch the suction means from the first state to the second state when a speed signal emitted by the speed detection means and received by the control unit indicates that the vehicle, in the acceleration phase, has exceeded a speed which is between 40 and 60 km / h.Indeed, although the threshold speed mentioned in the examples above relating to the capture system is dependent on certain specificities linked to the materials used. for the brake lining and brake design, it appears that for the vast majority of vehicles, the peak emissions start between 40 and 60 km / h. Thus a control unit configured with a speed chosen in this range constitutes a good compromise for recovering particles and preserving the environment on a large scale, and effectively, because it does not require specific calibration for each vehicle.

[0026] The invention also relates to a method for calibrating a particle capture system according to one of the above embodiments, the method comprising, in this order: providing a disc brake comprising a disc, a pair of linings and a caliper; rotating the disc; activating the brake by applying a force to the linings in contact with the disc; ceasing activation of the brake; accelerating the disc, during which: the particles emitted by the brake are detected and the rotational speed of the disc is measured; determining the variations in the emission of the particles as a function of the rotational speed of the disc; identifying a peak in particle emissions over these variations; determining a specific value of rotational speed of the disc corresponding to the peak in emissions;and configuring the control unit of the capture system with said specific value as the first threshold rotation speed.;

[0027] The specific rotational speed value corresponding to the emissions peak may be a speed value at which the maximum emissions are produced. Alternatively, the specific value may be a characteristic speed value at the beginning of the peak, i.e., for example, when the emissions versus time or rotational speed curve increases abruptly. A tolerance margin of, for example, 10% of this value may be applied to ensure that the emissions peak is not even initiated and that particles are sucked away before this peak even appears.

[0028] Optionally, the calibration can result in the creation of a database including the disk, lining and caliper triplets (their design, material, etc.) and the threshold rotation speed value associated with each triplet. The control unit can access this database, identify the disk, linings and caliper to identify the triplet in play and find the threshold rotation speed value to be taken into account in the control of the suction means.

[0029] According to an advantageous embodiment, the method further comprises: measuring a residual braking torque when the brake is inactivated; and configuring the control unit according to the following principles: if the residual braking torque is greater than a threshold value of residual braking torque, the control unit is configured to maintain the suction means in the second state as soon as the disk rotation speed signal indicates that the disk is rotating at a speed greater than a threshold rotation speed; and if the residual braking torque is less than the threshold value of residual braking torque, the control unit is configured to maintain the suction means in the second state, following the switch from the first state, for a duration of between 5 and 30 seconds, preferably between 10 and 15 seconds, then, after this duration, to switch the suction means back to the first state.

[0030] Indeed, the inventors' investigation efforts have made it possible to establish that a residual braking torque, due to the permanent contact of the linings on the disc even in the absence of braking force, could have a significant impact on the emission of particles. In extreme situations, over the total lifetime of the linings, 30 to 40% of the particle emissions could occur because of this residual torque. Thus, when the residual torque induced by the disc / lining / caliper triplet is higher than a predetermined threshold, it may be advantageous to configure the control unit to maintain suction independently of the rotational speed of the disc.

[0031] The invention also relates to a method for controlling a braking particle capture system of a disc brake, the capture system comprising particle suction means, the method comprising: detecting the rotational speed of the disc; and when the rotational speed of the disc exceeds a first threshold rotational speed, switching the state of the suction means, from a first state, in which the suction means produce a first suction level, to a second state, in which the suction means produce a second suction level, higher than the first suction level.

[0032] Optionally, the particle capture system used in this method is in accordance with one of the embodiments set out above and / or is calibrated by one of the calibration methods set out above.

[0033] Thus, the various aspects of this disclosure help to preserve the environment. If a conventional suction system operating only during braking allows a capture efficiency of around 62%, the activation of a certain level of suction beyond a threshold speed allows this value to exceed 71%. Brief description of the drawings

[0034] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analyzing the attached drawings, in which:

[0035] [Fig. 1] shows a vehicle, a disc brake and a particle capture system.

[0036] [Fig. 2] shows a first reading of particle emissions.

[0037] [Fig. 3] shows a second particle emission reading.

[0038] [Fig. 4] shows a third particle emission reading.

[0039] [Fig. 5] shows a fourth particle emission reading.

[0040] [Fig. 6] shows a fifth particle emission reading.

[0041] [Fig. 7] shows a sixth particle emission reading.

[0042] [Fig. 8] shows one process. Description of the embodiments

[0043] The figures represent different aspects of the invention in a schematic manner. Unless explicitly indicated otherwise, each aspect shown in a figure may be combined with other aspects shown in other figures in any technically possible combination.

[0044] Figure 1 illustrates a possible application for the present disclosure. A vehicle 1, automobile (car, van, truck, etc.) or railway (train, tram, metro, etc.), comprises a braking device 2 of the disc brake type. It is understood that the invention is not limited to this type of vehicle or to this type of brake: indeed, those skilled in the art will know how to adapt the invention for other vehicles (motorcycle, bicycles, etc.) or for other types of brakes (drum, multi-disc, etc.).

[0045] The brake 2 is essentially composed of a disc 4 secured to a wheel of the vehicle 1 and rotating at a rotation speed denoted W around an axis 6. The rotation speed W is proportional to the linear speed V of advance of the vehicle 1. A caliper 8 partially overlapping the periphery of the disc 4 encloses two linings 10, 12. The application of a force parallel to the axis 6 by means of one or more pistons generates a braking torque by the friction of the linings 10, 12 on the respective faces of the disc 4.

[0046] During a braking operation, the friction of the linings 10, 12 on the disc 4 generates particles (dust, PM10, PM25, etc.). These particles are harmful to the environment: their composition may contain elements that are difficult for the environment to assimilate and harmful to the respiratory functions of people who are exposed to them on a recurring basis.

[0047] A particle capture system 20 is thus provided for recovering the particles. Such a system 20 may for example be in the form presented in document FR 3 057 040 A1 or in another form, in particular according to the examples in the patent literature published in the name of the company Tallano.

[0048] The capture system 20 may thus comprise a vacuum source 22, here represented as a turbine, which is fluidically connected, for example by means of a (flexible) pipe 24, to a zone close to the interface between the linings 10, 12 and the disc 4. In one example, the linings 10, 12 may be provided with a through hole and the pipe 24 may be connected to the rear face of the linings 10, 12. The pipe 24 may comprise a filter 26 or a particle collection tank. This filter 26 may for example be dimensioned so as not to require maintenance and so as to be able to be replaced simultaneously with a replacement of the linings 10, 12. The filter 26 may be arranged downstream or upstream of the turbine 22.

[0049] The operation of the turbine 22 can be controlled, via a connection 28, by a control unit 30. The control unit 30 is shown schematically here. It can comprise a memory, a processor and communication buses. It can take the form of hardware and / or software elements dedicated to the control of the capture system or be integrated into one of the main controllers of the vehicle (ICAN, ECU, EMS, etc.) or of the industrial machine.

[0050] A sensor 32 can detect the rotational speed of the disc 4. This sensor 32 can be integrated into an assembly arranged locally near the disc 4, such as for example a brake assist system (ABS) or an electronic trajectory correction system (ESP). The sensor 32 can alternatively be an indirect sensor, which detects for example the rotational speed of the crankshaft and deduces therefrom the rotational speed of the disc and / or the linear forward speed of the vehicle. For industrial machines, the speed of the disc can be obtained by any suitable means.

[0051] The sensor 32 communicates a signal 34 to the control unit 30. The signal 34 can be an electrical potential which corresponds to an image of the rotational speed of the disk 4. The assembly is calibrated so that the control unit 30 can transpose the electrical potential of the signal 34 into a rotational speed value of the disk 4.

[0052] The control unit 30 is configured to detect an acceleration, i.e. a positive variation in the rotational speed of the disk 4 and to estimate when the speed of the disk 4 exceeds a threshold. As explained with reference to the following figures, the detection of this threshold causes the control unit 30 to switch the operation of the turbine 22 to increase its suction level, for example by increasing the power supply intensity of the turbine. The suction level can take any value between zero suction and maximum suction of the turbine 22.

[0053] Figure 2 illustrates a reference test in which no particle capture is performed during acceleration.

[0054] The x-axis represents time (e.g., in seconds). The y-axis represents (1) the disk rotation speed W (e.g., in revolutions per minute); (2) the suction level p (e.g., in bar); and (3) the quantity of CPC particles (for condensation particle counter) released into the environment, i.e., particles produced by the brake and not captured by the capture system. As mentioned above, other physical quantities can be used to characterize the suction level or the quantity of particles emitted.

[0055] The rotational speed of the disc may be proportional to a physical reality in which the system is used. For a vehicle, this may be the linear speed of the vehicle (V=RW where R is the radius of the vehicle wheel). Thus, in all examples of the present disclosure, when the brake is a vehicle brake, the expression "rotational speed of the disc" may be replaced by "vehicle speed". For an industrial machine, the physical reality in question may be the power delivered (power = torque x W) when the torque is constant over a sufficient range of values ​​of rotational speed of the disc. Thus, in all examples of the present disclosure, when the brake is an industrial machine brake, the expression "rotational speed of the disc" may be replaced by "machine power".

[0056] The curve in Figure 2 shows a braking operation taking place between time Tf 1 and time Tf2. During this braking operation, the speed W decreases. The suction is activated with a braking suction pressure, noted pf. Despite the suction, there may be a temporary increase in particle emissions, as the capture system cannot claim to guarantee total capture of all the particles produced during braking.

[0057] In this illustration, after Tf2, the disc accelerates. The suction is inactivated and becomes zero after Tf2. For simplification, the rotational speed is described as evolving linearly, but identical results are obtained for a rotational speed that exhibits a different evolution.

[0058] It can be seen from this figure that at low speeds, few particles are emitted and that a peak appears for a certain range of speed values. The speed Wa, reached at time Ta, indicates the start of the peak. This start can be determined analytically by an abrupt increase in the quantity of emitted particles, i.e. a derived signal (as a function of time or as a function of speed) greater than a threshold value. The peak ends at the speed Wb, reached at time Tb. Without being bound by theory, the end of the peak is assimilated to an exhaustion of the particles present at the lining / disc interface. A speed Wc, reached at time Te, can be defined as a speed at which the largest quantity of particles is emitted.

[0059] It is important to note that the identification of this peak by the inventors results from extensive experiments and that the appearance of this peak is not intuitive or expected for those skilled in the art. On the contrary, all of the literature recommends the suction of particles at the time of braking, considering that it is at this very moment that the particles are torn from the linings and that it is therefore appropriate to carry out the suction simultaneously with a braking operation.

[0060] Compared to Figure 2, Figure 3 shows a test with a similar speed variation, in which the particle capture system is activated at the start of the peak: at time T1, the suction means are switched from a low or zero suction level (p1) to a higher suction level (p2). T1 can be time Ta in Figure 2, at the start of the peak (W1=Wa in Figure 2). It should be noted that other choices can be made to switch the suction means to their second state, such as Te, or a few seconds before Ta, or before the disk reaches speed Wa, for example when the disk reaches a speed 10% lower than Wa.

[0061] The change of state of the suction means is materialized by the passage from a depression p1 (which can be zero) to a depression p2, greater (in absolute value) than p1. As mentioned above, other parameters (flow speed, flow rate) can be used to qualify the distinction between the first suction level and the second suction level.

[0062] In this example, the value of p2 is less than the value of pf, suction depression during braking.

[0063] It is observed that the peak of particle emissions, which is present in Figure 2 in the absence of suction, is considerably flattened when the suction is increased from the speed value W1. The timing of this suction allows a compromise between permanent suction (and therefore energy consumption without gain for the environment) and the absence of suction (and therefore a release of emissions into the environment).

[0064] Figure 3 also shows that the turbine can switch back, under the impulse of the control unit, to the first state after a certain duration Dt, i.e. at time T1+Dt. The duration Dt can be between 5 and 30 seconds, preferably between 10 and 15 seconds.

[0065] It should be noted that the increase in emissions during braking remains unchanged between Figure 2 and Figure 3 since the suction is the same.

[0066] Figure 4 illustrates the fact that when the speed drops below a certain threshold W2, which may be equal to W1, the control unit switches the suction means to the first state (lower suction level). This switchover may possibly (as drawn) occur before the duration Dt has elapsed. Indeed, since the emission of particles stops when the speed drops, it is no longer necessary to maintain a high suction level.

[0067] Figure 5 represents a variant in which the suction level is kept high as long as the speed remains above a threshold W3, which can be equal to W1.

[0068] Figure 6 shows a comparison between a system "a" and a system "b". The C axis represents the friction torque (e.g. in Nm) of the pads on the disc. During braking, the torque has the value Cf, braking torque. Outside the braking phase, by construction, the pads remain in contact with the disc without, however, applying sufficient force to slow the disc. This contact can generate a so-called residual torque, the importance of which is specific to a disc, pad, caliper triplet. Thus, a brake "a" will, for example, have a residual torque Ca lower than a system "b" with a residual torque Cb.

[0069] The inventors have highlighted the implication of the residual torque value on the emission of particles: Figure 6 shows that system "b" which has the greatest residual torque results in the emission of a greater number of CPCb particles than system "a" which emits fewer CPCa particles. The difference between the two curves can fade at the emission peaks: in fact the emission peaks in the braking phase or near the threshold speed can be at equivalent levels independent of the residual torque level.

[0070] Figure 7 shows that the suction level control law can be chosen to be different for a system with a high residual torque (above a given threshold): for system b, the depression remains at a level p2 after the passage of speed W1 while the level can fall back to p1 for system a with low residual torque.

[0071] In the examples of the suction control method given in Figures 2 to 7, it is understood that if, after the braking phase, a new braking phase takes place, the suction is again activated at the pf level.

[0072] The threshold speed W1 can correspond to a speed of vehicle 1 which is between 40 km / h and 60 km / h.

[0073] Figure 8 illustrates a method 1000 of calibrating a particle capture system which may be the system previously described in connection with Figure 1 and / or controlled according to what is described in connection with one or more of Figures 2 to 7.

[0074] Step 100 consists of providing a disc brake, for example of the type shown in Figure 1. During step 200, the disc is rotated. For example, for a vehicle, the discs are rotated indirectly by the engine. Step 300 materializes a braking phase, by applying a force to the pads. Braking reduces the speed of the disc to a speed which may not be zero. Step 400 marks the end of brake activation.

[0075] In step 500, the disk is accelerated, its rotational speed is monitored, and the emitted particles are measured. The rotational speed can be detected directly by a dedicated sensor, which can be integrated into a brake assist or trajectory correction device. Alternatively, the rotational speed can be measured indirectly. The emitted particles can be detected by a suitable sensor, for example CPC.

[0076] Particle emission and velocity data are recorded at all times. A curve can then be plotted, expressing the variations in particle emissions as a function of the disk's rotational speed.

[0077] These variations include a peak which is to be identified at step 700.

[0078] The specific speed at which this peak occurs is identified in step 800. As illustrated in Figures 2 and 3, the specific speed may be chosen to be that which begins the peak, or a slightly lower speed, for example 10% lower than the start of the peak, to anticipate suction before the peak occurs.

[0079] Optionally, as discussed in connection with Figures 6 and 7, the residual braking torque can be measured at a time when the brake is not activated.

[0080] Step 900 consists of configuring the control unit. This involves, in particular, recording the peak-specific speed value in a memory of the control unit dedicated to the threshold speed value W1.

[0081] The configuration step 900 may also consist of defining a suction strategy, in particular in connection with the measured residual torque. Thus, if the residual braking torque is greater than a threshold value of residual braking torque, the control unit may be configured to maintain the suction means at a high suction level as soon as the disk rotation speed signal indicates that the disk is rotating at a speed greater than a threshold rotation speed; and if the residual braking torque is less than the threshold value of residual braking torque, the control unit may be configured to maintain the suction means in the second state, following the switch from the first state, for a duration of between 5 and 30 seconds, preferably between 10 and 15 seconds, then, after this duration, to switch the suction means back to the first state.

Claims

Claims

1. System (20) for capturing braking particles emitted by a disc brake (2), the capture system (20) comprising: particle suction means (22, 24, 26), capable of adopting a first state, in which the suction means (22, 24, 26) produce a first suction level (p1), and a second state, in which the suction means produce a second suction level (p2), higher than the first suction level (p1); and a control unit (30) regulating the state of the suction means (22, 24, 26), the system (20) being characterized in that the control unit (30) is configured to switch the suction means (22, 24, 26) from the first state to the second state when a rotation speed signal (34) of the disc (4) of the brake (2), received by the control unit (30), indicates that the disc (4), in the acceleration phase, has exceeded a first threshold rotation speed (W1).

2. A capture system (20) according to claim 1, wherein the first suction level (p1) corresponds to an absence of suction.

3. Capture system (20) according to one of the preceding claims, in which the control unit (30) is configured to maintain the suction means (22, 24, 26) in the second state, following the switching, for a duration (Dt) of between 5 and 30 seconds, preferably of between 10 and 15 seconds, then, after this duration (Dt), to switch the suction means (22, 24, 26) back into the first state.

4. Capture system (20) according to one of the preceding claims, in which the control unit (30) is configured to switch the suction means (22, 24, 26) from the second state to the first state, if the following two conditions are met: a rotation speed signal (34) of the disk (4), received by the control unit (30), indicates that the disk (4), in the deceleration phase, passes below a second threshold rotation speed (W2), possibly equal to the first threshold rotation speed (W1); and the brake (2) is inactive, the switching of the suction means (22, 24, 26) from the second state to the first state being potentially carried out after a time delay of 10 to 15 seconds during which these two conditions are maintained true.

5. Capture system according to one of the preceding claims, in which the control unit (30) is configured to maintain the suction means (22, 24, 26) in the second state as soon as the rotation speed signal (34) of the disk (4) indicates that the disk (4) is rotating at a speed greater than a third threshold rotation speed (W3), preferably equal to the first and / or the second threshold rotation speed (W1, W2).

6. Motor or railway vehicle (1) comprising: a disc brake (2); a system for capturing braking particles (20) emitted by the disc brake (2); and means for detecting the speed of the vehicle, the capture system (20) comprising: particle suction means (22, 24, 26), capable of adopting a first state, in which the suction means (22, 24, 26) produce a first suction level (p1), and a second state, in which the suction means produce a second suction level (p2), higher than the first suction level (p1); and a control unit (30) regulating the state of the suction means (22, 24, 26), the vehicle being characterized in that the control unit (30) is configured to switch the suction means (22, 24, 26) from the first state to the second state when a speed signal emitted by the speed detection means and received by the control unit (30) indicates that the vehicle (1), in the acceleration phase, has exceeded a speed which is between 40 and 60 km / h.

7. A method (1000) for calibrating a particle capture system according to one of claims 1 to 5 or a vehicle according to claim 6, the method comprising, in this order: providing (100) a disc brake (2) comprising a disc (4), a caliper (8) and a pair of linings (10, 12); rotating (200) the disc (4); activating the brake (300) by applying a force to the linings (10, 12) in contact with the disc (4); ceasing activation of the brake (400); accelerating the disc (500), during which: the particles emitted by the brake (2) are detected and the rotational speed (W) of the disc (4) is measured; determining (600) the variations in the emission of the particles as a function of the rotational speed (W) of the disc (4); the identification of a peak (700) of particle emission on these variations;determining (800) a specific value (Wa) of rotation speed of the disk (4) corresponding to the emission peak; and configuring (900) the control unit (30) of the capture system (20) with said specific value (Wa) as first threshold rotation speed (W1).;

8. A calibration method according to claim 7, further comprising: measuring (850) a residual braking torque when the brake is inactivated; and configuring (900) the control unit according to the following principles: o if the residual braking torque (Cb) is greater than a threshold value of residual braking torque, the control unit (30) is configured to maintain the suction means in the second state as soon as the disk rotation speed signal indicates that the disk is rotating at a speed greater than a threshold rotation speed (W1); and o if the residual braking torque (Ca) is less than the threshold value of residual braking torque, the control unit (30) is configured to maintain the suction means in the second state, following the switch from the first state, for a duration of between 5 and 30 seconds, preferably between 10 and 15 seconds, then, after this duration, to switch the suction means back to the first state.

9. Method for controlling a system (20) for capturing braking particles of a disc brake, the capture system comprising particle suction means, the method comprising: detecting the rotation speed (W) of the disc (4); and when the rotation speed of the disc exceeds a first threshold rotation speed (W1), switching the state of the suction means, from a first state, in which the suction means produce a first suction level (p1), to a second state, in which the suction means produce a second suction level (p2), higher than the first suction level (p1).

10. A method according to claim 9, wherein the particle capture system (20) is according to one of claims 1 to 5 and / or is calibrated by a calibration method according to claim 7 or 8.

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