VEHICLE AND ITS IMPLEMENTATION PROCESS

Abstract

Vehicle (1) comprising at least one disc brake (2) including: a pair of brake linings (10, 12) having a brake particle collection element; and fluidly connected particle suction means (22, 24, 26) controlled by a control unit (30) between an active and an inactive state, the control unit (30) being configured to keep the suction means (22, 24, 26) inactive when the speed (V) of the vehicle (1) is below a threshold speed. Abstract figure: Figure 1

Description

Title of the invention: VEHICLE AND ITS IMPLEMENTATION METHOD technical field

[0001] This disclosure relates to the field of motor vehicles or railways and in particular their braking systems. The context specifically addresses environmental protection aspects related to the extraction of brake particles emitted by friction brakes, particularly disc brakes. Previous technique

[0002] Document FR 3 057 040 A1 describes a disc brake lining equipped with a collection groove and a through orifice, fluidly connected to suction means. This lining allows for the efficient suction of brake dust along its entire radial height. The suction means include a turbine generating a vacuum that draws in the dust and directs it to a collection filter.

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

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

[0005] Thus, existing systems simply recommend systematically and solely the activation of suction during braking phases and the deactivation of suction after braking phases.

[0006] However, when driving in a hostile environment, such as when fording a stream, activating the particle suction system leads to water being drawn into the pneumatic circuit, rendering it inoperative. None of the aforementioned disclosures identifies this problem or provides any solutions. Summary

[0007] The present disclosure thus proposes a vehicle and its method of implementation which do not impair the operation of the braking particle capture system when crossing a ford.

[0008] A vehicle is thus proposed comprising at least one disc brake including: a pair of brake linings having a brake particle collection element; and particle suction means fluidly connected to each element of collection and controlled by a control unit between an active state and an inactive state, the control unit being configured to keep the suction means inactive when the vehicle speed is below a threshold speed.

[0009] The inventors have demonstrated that, surprisingly, the brake pad collection elements (for example, a groove on the trailing edge of the pad, a peripheral groove, a central suction orifice, a caliper cover, a suction nozzle, etc.), in contact with the disc, can act as a particle reservoir during braking, even in the absence of suction. It is therefore possible to capture brake particles without necessarily activating suction at the precise moment of braking. Thus, the suction can be controlled so as not to activate when crossing a ford, which is certainly done at a speed lower than the usual cruising speed of a motor vehicle, without, however, hindering the efficiency of particle suction and therefore the protection of the environment and people.

[0010] The "active" state corresponds to the generation of a depression and therefore of a flow of suction air, while the "inactive" state corresponds to an absence of suction.

[0011] By "control unit", it is appropriate to understand a hardware and / or software element dedicated to the control of the capture system or integrated into one of the main controllers of the vehicle (CAN, ECU, EMS,...).

[0012] According to another aspect, the threshold speed is between 20 km / h and 30 km / h. The speed at which a ford is crossed is generally less than a value within this range.

[0013] According to another aspect, the control unit is configured to command a succession of cycles, each cycle comprising a first stage of a first duration during which the suction means are active and a second stage of a second duration during which the suction means are inactive. The inventors have demonstrated that during suction, particles stored in the disc's asperities are drawn in, whether the suction occurs during brake activation or in the absence of braking. It is therefore possible to maintain suction efficiency by programming cyclic suction that is not necessarily linked to brake activation. Cyclic activation and deactivation should be understood as an alternation, or a continuous and direct succession of switches between the active and inactive states.Furthermore, it is implicit that the first and second durations are non-zero, otherwise the aspiration would be continuous or totally inactive.

[0014] According to another aspect, the control unit is configured to control the active or inactive state of the suction means independently of brake activation. By activating the suction independently of brake activation, the need to rapidly activate the suction at the very moment of braking is eliminated: indeed, in At the start of braking, a peak in particle production occurs, requiring the immediate creation of a low-pressure area to absorb a significant portion of it. Consequently, there is no longer a need to equip the system with a powerful motor that would generate spikes in electrical consumption.

[0015] According to another aspect, the control unit is configured to activate the suction means upon brake activation and to maintain them in the active state until the end of brake activation or for a few seconds after the end of brake activation. In this case, most of the particles produced during braking are captured.

[0016] According to another aspect, each collection element is a groove, optionally a peripheral groove completely surrounding the trim.

[0017] The invention also relates to a method of implementing a vehicle according to one of the embodiments described above, the method comprising receiving a speed signal by the control unit and the control, by the control unit, of the suction means to keep the suction means inactive when the speed of the vehicle is below a threshold speed.

[0018] According to another aspect, the threshold speed is between 20km / h and 30 km / h.

[0019] According to another aspect, the method includes a cyclical control phase of the aspiration means, the cyclic phase comprising a succession of cycles, each of the cycles comprising a first stage of a first duration during which the aspiration means are active and a second stage of a second duration during which the aspiration means are inactive.

[0020] According to another aspect, the first duration is between 5 seconds and 2 minutes, preferably between 10 seconds and 1 minute.

[0021] According to another aspect, in which the second duration is between 30 seconds and 30 minutes, preferably between 4 and 10 minutes.

[0022] According to another aspect, the ratio between the first duration and the second duration is between 1 / 3 and 1 / 10.

[0023] According to another aspect, the active or inactive state of the suction means is controlled independently of brake activation. In this case, the suction means are controlled exclusively according to the cyclic phase (and as soon as the speed is greater than the threshold speed).

[0024] According to another aspect, when the brake is activated, the suction means are activated and remain active until the brake activation is complete or for a few seconds afterward. This braking phase interrupts the cyclic phase, which resumes after braking. This strategy combines efficient particle capture outside of braking and efficient capture during braking.

[0025] According to another aspect, each collection element is a groove, optionally a peripheral groove completely surrounding the trim. Brief description of the drawings

[0026] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analysis of the accompanying drawings, on which:

[0027] [Fig-1] shows a vehicle, a disc brake and a sensor system particles.

[0028] [Fig.2] illustrates different examples of brake pads.

[0029] [Fig.3] shows a flowchart of a brake implementation process.

[0030] [Fig.4A] represents a flowchart of a suction process.

[0031] [Fig.4B] shows a chronogram of the process of [Fig.4A].

[0032] [Fig.5] illustrates a timing diagram when the suction is controlled during braking, the speed remaining above the threshold speed.

[0033] [Fig.6] illustrates a timing diagram when the suction is commanded during braking, with the speed reducing below the threshold speed. Description of the implementation methods

[0034] The figures schematically represent different aspects of the invention. Unless explicitly stated otherwise, each aspect shown in a figure can be combined with other aspects shown in other figures in all technically possible combinations.

[0035] Figure 1 illustrates a road vehicle 1 (car, van, truck, etc.) or rail vehicle (train, tram, etc.) which includes a braking device 2 of the disc brake type. It is understood that this disclosure is not limited to this type of vehicle or this type of brake: indeed, a person skilled in the art will be able to adapt the invention for other vehicles (motorcycle, bicycles, etc.) or for other types of brakes (drum, multi-disc, etc.).

[0036] The brake 2 essentially consists of a disc 4 attached to a wheel of the vehicle 1 and rotating at a rotational speed denoted W about an axis 6. The rotational speed W is proportional to the linear speed V of the vehicle 1. A caliper 8 partially overlapping the periphery of the disc 4 contains two brake pads consisting of a backing plate and a lining 10, 12. For example, the pads could be those shown in [Fig. 2] and based on [Fig. 1] of document FR 3 087 238 A1, Figure 3A of document GB 2 533 476 A, or Figures 3 or 4 of document KR 2020 0016 690 A. Applying a force parallel to the axis 6 by means of one or more pistons generates a braking torque through the friction of the linings 10, 12 on the surfaces respective of disc 4.

[0037] During braking, the friction of the brake linings 10, 12 on the disc 4 generates particles (dust, PM10, PM2.5, 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 repeatedly exposed to them.

[0038] A particle capture system 20 is thus provided to recover the particles. Such a system 20 may, for example, be in the form shown in document FR 3 057 040 Al or in another form, in particular according to the examples in the patent literature published in the name of the company Tallano Technologie(s).

[0039] The collection system 20 can thus include a vacuum source 22, here represented as a turbine, which is fluidically connected, for example by means of a flexible conduit 24, to a collection element at the interface between the seals 10, 12 and the disc 4. In one example, the seals 10, 12 may be provided with a through hole and the conduit 24 may be connected to the rear face of the seals 10, 12. The conduit 24 may include a filter 26 or a particle collection tank. This filter 26 may, for example, be sized to be maintenance-free and to be replaced simultaneously with the replacement of the seals 10, 12. The filter 26 may be located upstream or downstream of the turbine 22.

[0040] 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 may include memory, a processor, and communication buses. It may take the form of hardware and / or software components dedicated to controlling the sensor system or be integrated into one of the vehicle's main controllers (CAN, ECU, EMS, etc.).

[0041] The control unit 30 controls the amount of current supplied to the turbine motor 22 and thus controls its speed. When no electrical current is supplied to the motor driving the turbine 22, the turbine 22 is stationary and no vacuum is created in the duct 24. No particle suction is produced. In this case, the suction means 20, 22, 24, 26 are said to be in an inactive state. When an electrical current is supplied to the motor driving the turbine 22, the turbine starts moving and suction is produced. In this case, the suction means 20, 22, 24, 26 are said to be in an active state, regardless of the (non-zero) speed of the turbine and / or the (non-zero) amplitude of the electrical current supplied to the motor.

[0042] In one variant, the active or inactive state of the suction means is regulated by a valve disposed in the pneumatic suction circuit and the turbine can be driven continuously.

[0043] Figure 2 shows three examples of brake pads 40, 50, 60 that can be used with the particle capture system. Other variants are also conceivable.

[0044] The plate 40 includes a base 42 on which the trim 10 is fixed. In the trim 10, a particle collection groove 44 is formed. This groove is connected to suction means.

[0045] The plate 50 includes a peripheral groove 54 which follows the profile of the lining 10. An air inlet is provided in the center of the lining 10 and an air outlet is arranged in the groove 54.

[0046] The plate 60 is formed of a trim 10 and a skirt 62 which is intended to be arranged around the trim 10 to form a suction zone 64 between the trim 10 and the skirt 62.

[0047] Thus, various collection elements 44, 54, 64 can be provided on a plate for the aspiration of particles.

[0048] Figure 3 shows a method 100 for implementation on a vehicle (1 in Figure 1). The various steps are presented as occurring sequentially to facilitate understanding of the process, but these steps can be carried out continuously, sometimes simultaneously. The method 100 includes a step 110 of receiving a speed signal V from the vehicle by the control unit 30. The signal can be transmitted by any suitable sensor or processing unit of the vehicle. This step can, for example, be carried out continuously or sequentially at a frequency between 1 and 50 Hz.

[0049] In step 120, the speed V (actual speed) received by the control unit 30 is compared to a threshold speed V0. The threshold speed can take any value, including an integer value, between 20 km / h and 30 km / h.

[0050] If the speed V is less than V0, the process 100 continues with step 130, which controls (or maintains) the inactivity of the suction means. Thus, the system ensures that no special particle suction is performed at low speeds and that water crossing a ford does not enter the suction circuit. Experience has shown that driving at higher speeds, even in rain, does not present this risk of water entering the circuit.

[0051] If the speed V is greater than V0, the suction can be controlled in step 140 according to one of the following modes: (a) the suction is triggered when the brake is activated and ceases when the brake activation is discontinued; (b) the suction is triggered when the brake is activated and ceases a few seconds (for example, 1, 2, 3, 4, 5, 6, or 7 seconds) after the brake activation is discontinued; (c) the suction is cyclic and independent of brake activation: whether the brake is activated or not, the suction maintains its cyclic rhythm; (d) the suction is cyclic and the suction means are also activated when the brake is activated, as described in modes (a) or (b) above. Regardless of the operating mode, if the speed falls below V0, all suction ceases.

[0052] The control unit can be configured to remain in one of these operating modes. Alternatively, the control unit can switch from one mode to another in a predetermined manner, based on predefined parameters (for example, a level of wear on the linings or the disc, a level of filter clogging, etc.). In one variant, the switchover is performed by a user selection.

[0053] Since the speed V is constantly monitored, step 140 ceases as soon as a speed V lower than V0 is detected.

[0054] The operating modes (a) and (b) corresponding to an application of suction at the time of braking do not require further explanation: as long as the speed V remains greater than V0, the suction becomes active at the time of braking and stops at the end of braking, possibly with a delay of a few seconds.

[0055] A cyclic suction 1000 (mode (c) above) is illustrated in Figures 4A and 4B. In a first step 1100 of a first duration T1, the suction means are activated. In a second step 1200 of a second duration T2, the suction means are deactivated.

[0056] The two steps 1100, 1200 form a cycle C which is repeated (as long as the vehicle speed remains above the threshold V0 and regardless of brake activation). The two steps follow each other directly in time.

[0057] This succession over time is also represented in [Fig. 4B]. The x-axis is the time axis. The curve shows the intervals corresponding to the changes of state between the active state and the inactive state, each state being maintained for a respective duration T1, T2.

[0058] It appears that cyclic suction is as effective as suction limited to braking sequences. Approximately 67% of the PM10 particles produced are captured. Cyclic suction allows for a lower turbine acceleration, as it is not necessary to rapidly increase the turbine speed to absorb the particle peak that occurs during braking. Thus, for the same particle capture rate, a smaller engine can be selected.

[0059] The following table shows the quantities of PM10 particles detected (produced by the brake and not captured) during a standardized WLTP cycle, for different suction configurations (in mg per km and per vehicle brake): Continuous suction Cyclic suction (T1=1 min; T2=3 min) Cyclic suction (T1=1 min; T2=6 min) Cyclic suction (T1=1 min; T2=13 min) Cyclic suction (T1=1 min; T2=27 min) 1.8 2.2 2.6 3.6 3.7 Table 1

[0060] Tests with different values ​​of T1 and T2 show that when the T1 / T2 ratio is less than 10%, the quantity of particles detected (produced but not captured) is close to 3.7 mg / km / brake, which is the quantity detected in the absence of suction. For a T1 / T2 ratio between 15% and 30%, the efficiency is acceptable. Above 30%, the benefits in particle capture are offset by significant power consumption.

[0061] Regarding the duration values, the duration Tl can be between 5 seconds and 2 minutes, preferably between 10 seconds and 1 minute. Below this range, it becomes necessary to provide for a rapid acceleration of the turbine so that it quickly reaches steady state (and therefore requires a powerful and energy-intensive motor) before the end of Tl. Above this range, the electrical consumption is significant.

[0062] The second duration T2 can be between 30 seconds and 30 minutes, preferably between 4 and 10 minutes. For the reasons mentioned above, the duration T2 is chosen so that the ratio between the first duration T1 and the second duration T2 is between 1 / 3 and 1 / 10.

[0063] The following table shows the quantities of PM10 particles detected (produced by the brake and not captured) during a standardized WLTP cycle, for different suction configurations (in mg per km and per vehicle brake): Cyclic aspiration (T1=1 min; T2=6 min) Aspiration 2 times 30 seconds interrupted by 5 minutes at V0 Aspiration 20 seconds then 3 minutes at V0 then aspiration 40 seconds 2.6 2.7 2.7 Table 2

[0064] Suction tests with interruption (due to a speed becoming below the threshold V0) seem to confirm that the effectiveness of the aspiration is substantially maintained, whether one aspirates once for 1 minute or one aspirates in several times (1 minute in cumulative time).

[0065] Figures 5 and 6 show timing diagrams according to the operating mode (d) mentioned above.

[0066] Figure 5 shows a situation in which the speed V remains above V0. The suction means are controlled according to a cyclic phase until a braking start time TD. Braking ceases at a braking end time TF. The speed has decreased between TD and TF without, however, falling below V0. At time TD, if, according to the imposed cycle, the suction means are active, then they remain active, and if, according to the imposed cycle, the suction means are inactive, then they are activated. The suction means are activated. until the end of the TF braking, optionally increased by a delay d. Thus, in the illustrated example, the suction means become inactive again at time TF+d.

[0067] A new cyclic phase begins after braking.

[0068] Figure 6 shows a situation in which the speed V falls below V0. In this example, which initially resembles that of Figure 5, at a time T0 during braking, the speed falls below the threshold V0. At this instant, the suction becomes inactive, despite the fact that braking is in progress. After braking, in the illustrated case, the speed remains below V0 and the suction remains inactive. If the speed V were to exceed V0 again, the suction would resume cyclically.

[0069] Figures 5 and 6 show in other words that in mode (d), suction is by default cyclic but that an activation of the brake gives priority to suction, but also that no suction is carried out, regardless of whether the brake is activated or not, when the vehicle speed is less than V0.

[0070] This strategy makes it possible to obtain a good compromise between the efficiency of particle capture and the reliability of the system which is not at risk of being submerged.

Claims

Demands

1. Vehicle (1) comprising at least one disc brake (2) including: - a pair of linings (10, 12) having a brake particle collection element (44, 54, 64); and - fluidly connected particle suction means (22, 24, 26) connected to each collection element and controlled by a control unit (30) between an active state and an inactive state, the control unit (30) being configured to • keep the suction means (22, 24, 26) inactive when the speed (V) of the vehicle (1) is less than a threshold speed (V0); and • make the suction means (22, 24, 26) inactive if they are active while the speed decreases and becomes less than the threshold speed (V0).

2. Vehicle (1) according to claim 1, in which the threshold speed (V0) is between 20km / h and 30 km / h.

3. Vehicle (1) according to claim 1 or 2, wherein the control unit (30) is configured to control a succession of cycles (C), each of the cycles (C) comprising a first stage (1100) of a first duration (T1) during which the suction means (22, 24, 26) are active and a second stage (1200) of a second duration (T2) during which the suction means (22, 24, 26) are inactive.

4. Vehicle (1) according to any one of claims 1 to 3, wherein the control unit (30) is configured to control the active or inactive state of the suction means (22, 24, 26) independently of the activation of the brake (2).

5. Vehicle (1) according to any one of claims 1 to 3, wherein the control unit (30) is configured to activate the suction means (22, 24, 26) upon activation of the brake (2), and to maintain them in the active state until the end of the brake (2) activation or until a few seconds after the end of the brake (2) activation.

6. Vehicle (1) according to any one of claims 1 to 5, wherein each collection element is a groove (44, 54, 64), optionally a peripheral groove (54) completely surrounding the trim.

7. Method (100) of implementing a vehicle according to any one of claims 1 to 6, the method comprising receiving (110) a speed signal (V) by the control unit (30) and the control (130), by the control unit (30), of the suction means (22, 24, 26) to keep the suction means (22, 24, 26) inactive when the speed (V) of the vehicle (1) is less than a threshold speed (V0) and to make the suction means (22, 24, 26) inactive if they are active while the speed decreases and becomes less than the threshold speed (V0).

8. Method (100) according to claim 7, wherein the threshold speed (V0) is between 20km / h and 30 km / h.

9. Method (100) according to claim 7 or 8, comprising a cyclic phase (1000) for controlling the suction means, the cyclic phase (1000) comprising a succession of cycles (C), each of the cycles (C) comprising a first step (1100) of a first duration (T1) during which the suction means (22, 24, 26) are active and a second step (1200) of a second duration (T2) during which the suction means (22, 24, 26) are inactive.

10. Method (100) according to claim 9, wherein the first duration (Tl) is between 5 seconds and 2 minutes, preferably between 10 seconds and 1 minute.

11. Method (100) according to claim 9 or 10, wherein the second duration (T2) is between 30 seconds and 30 minutes, preferably between 4 and 10 minutes.

12. A method (100) according to any one of claims 9 to 12, wherein the ratio between the first duration (T1) and the second duration (T2) is between 1 / 3 and 1 / 10.

13. Method (100) according to any one of claims 7 to 12, wherein the active or inactive state of the suction means (22, 24, 26) is controlled independently of the activation of the brake (2).

14. A method (100) according to any one of claims 7 to 12, wherein upon activation of the brake, the suction means (22, 24, 26) are made active, and are kept active until the end of the brake activation or a few seconds after the end of the brake activation.

15. Method (100) according to any one of claims 7 to 14, wherein each collection element is a groove (44, 54, 64), optionally a peripheral groove (54) completely surrounding the lining.

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