VEHICLE AND METHOD OF IMPLEMENTING IT

Abstract

Vehicle (1) comprising at least one disc brake (2) comprising: a pair of linings (10, 12) having a braking particle collection element; and particle suction means (22, 24, 26) fluidly 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 lower than a threshold speed. Abstract figure: Figure 1

Description

Title of the invention: VEHICLE AND METHOD FOR IMPLEMENTING SAME Technical field

[0001] The present disclosure relates to the field of motor or railway vehicles and in particular their braking devices. The context relates in particular to the aspects of environmental protection by the suction of braking particles emitted by friction brakes, in particular disc brake type 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 the maximum suction is controlled during braking.

[0004] Document FR 3 088 395 A1 introduces the concept of compensation of the suction according to 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] Thus, existing systems are content to systematically and only recommend 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 crossing a ford, activating the particle suction leads to water being sucked into the pneumatic circuit, which renders it inoperative. None of the aforementioned disclosures identifies this problem or provides solutions to it. Summary

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

[0008] There is thus proposed a vehicle comprising at least one disc brake comprising: a pair of linings having a braking particle collection element; and particle suction means fluidically 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 collection elements of the pad (for example a groove at 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 serve as a particle reservoir during the braking phases, even in the absence of suction. It is therefore possible to capture the braking particles without necessarily suctioning at the exact moment of braking. Thus, the suction can be controlled so as not to engage when crossing a ford, which is certainly done at a speed lower than a usual cruising speed for a motor vehicle, without however hindering the effectiveness of the 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 suction air flow, whereas the “inactive” state corresponds to an absence of suction.

[0011] By “control unit” is meant 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, etc.).

[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 lower than a value within this range.

[0013] According to another aspect, the control unit is configured to control a succession of cycles, each of the cycles comprising a first step of a first duration during which the suction means are active and a second step of a second duration during which the suction means are inactive. The inventors have demonstrated the fact that during suction, the particles stored in the asperities of the disc are sucked up, whether it is suction during activation of the brake or in the absence of braking. It is therefore possible to maintain suction efficiency by programming a cyclic suction which is not necessarily linked to the activation of the brake. Cyclic activation and deactivation is to be understood in the sense of an alternation, or a continuous and direct succession of switches between the active state and the inactive state.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 the activation of the brake. By activating the suction in a manner decorrelated from the activation of the brake, the need to quickly activate the suction at the very moment of braking is eliminated: in fact, in At the start of braking, a peak in particle production occurs, which requires the immediate creation of a vacuum to absorb a significant portion of it. Consequently, there is no longer any need to provide the system with a powerful motor causing peaks in electrical consumption.

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

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

[0017] The invention also relates to a method for implementing a vehicle according to one of the embodiments described above, the method comprising the reception of 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 20 km / h and 30 km / h.

[0019] According to another aspect, the method comprises a cyclic phase of controlling the suction means, the cyclic phase comprising a succession of cycles, each of the cycles 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.

[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 the activation of the brake. In this case, the suction means are exclusively controlled according to the cyclic phase (and as soon as the speed is greater than the threshold speed).

[0024] According to another aspect, upon activation of the brake, the suction means are made active, and are kept active until the end of the activation of the brake or a few seconds after the end of the activation of the brake. This braking phase interrupts the cyclic phase, which resumes after braking. This strategy combines efficiency of particle capture outside of braking and efficiency during braking.

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

[0026] Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the attached drawings, in which:

[0027] [Fig-1] shows a vehicle, a disc brake and a data capture 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 timing diagram of the process of [Fig.4A].

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

[0033] [Fig.6] illustrates a timing diagram when the suction is controlled by braking, the speed reducing below the threshold speed. Description of the embodiments

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

[0035] [Fig.l] illustrates a vehicle 1, road (car, van, truck, etc.) or rail (train, tram, etc.) which comprises a braking device 2 of the disc brake type. It is understood that the present disclosure is not limited to this type of vehicle or to this type of brake: in fact, 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.).

[0036] The brake 2 is essentially composed of a disc 4 secured to a wheel of the vehicle 1 and rotating at a rotational speed denoted W around an axis 6. The rotational 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 contains two brake pads formed of a base and a lining 10, 12. For example, the pads may be those shown in [Fig. 2] and inspired by [Fig. 1] of document FR 3 087 238 A1, by figure 3A of document GB 2 533 476 A or by figures 3 or 4 of document KR 2020 0016 690 A. 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 sides of disc 4.

[0037] During a braking operation, the friction of the 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 to easily assimilated by the environment and harmful to the respiratory functions of people who are exposed to them on a recurring basis.

[0038] 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 Technologie(s).

[0039] 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 collection element at 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 sized 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.

[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 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 (CAN, ECU, EMS, etc.).

[0041] The control unit 30 controls the amount of current that is supplied to the motor of the turbine 22 and thus controls its speed. When no electric current is supplied to the motor driving the turbine 22, the turbine 22 is stationary and no vacuum is created in the conduit 24. No suction of particles is produced. In this case, the suction means 20, 22, 24, 26 are said to be in an inactive state. When an electric current is supplied to the motor driving the turbine 22, the latter 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 electric current supplied to the motor.

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

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

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

[0045] The plate 50 comprises a peripheral groove 54 which matches 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 lining 10 and a skirt 62 which is intended to be arranged around the lining 10 to form a suction zone 64 between the lining 10 and the skirt 62.

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

[0048] [Fig. 3] shows a method 100 for implementation on a vehicle (1 in [Fig. 1]). The different steps are presented as taking place sequentially to facilitate understanding of the process, but these steps can take place continuously, sometimes jointly. The method 100 comprises 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 computing unit of the vehicle. This step can, for example, be carried out continuously or sequentially at a frequency of between 1 and 50 Hz.

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

[0050] If the speed V is lower than V0, the method 100 continues with step 130 which controls (or maintains) the inactivity of the suction means. Thus, the system guarantees that no particular particle suction measurement is carried out at low speed and that water when crossing a ford would not enter the suction circuit. Experience has shown that driving at higher speed, even in the rain, did not present this risk of water being ingested into the circuit.

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

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

[0053] The speed V being continuously monitored, step 140 stops as soon as a speed V lower than V0 is detected.

[0054] The operating modes (a) and (b) corresponding to an application of the 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 FIGS. 4A and 4B. In a first step 1100 of a first duration T1, the suction means are controlled to be active. In a second step 1200 of a second duration T2, the suction means are controlled to be inactive.

[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 independently of the activation of the brake). The two steps follow one another directly in time.

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

[0058] It appears that cyclic suction is as effective as suction that would be limited to braking sequences. Approximately 67% of the PM 10 particles produced are captured. Cyclic suction makes it possible to choose a lower turbine acceleration, because it is not necessary to quickly increase the turbine speed to absorb the particle peak that occurs during braking. Thus, for the same particle capture rate, a smaller motor can be chosen.

[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 (Tl=1min; T2=3min) Cyclic suction (Tl=1min; T2=6min) Cyclic suction (Tl=1min; T2=13min) Cyclic suction (Tl=1min; T2=27min) 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 and 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. Beyond 30%, the benefits on particle capture are offset by significant electrical consumption.

[0061] As regards the values ​​of the durations, the duration Tl can be between 5 seconds and 2 minutes, preferably between 10 seconds and 1 minute. Below this range, it becomes necessary again to provide rapid acceleration of the turbine so that it quickly reaches stationary mode (and therefore a powerful and power-hungry engine) before the end of Tl. Above this range, the electrical consumption is significant.

[0062] The second duration T2 may 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 (Tl=1min; T2=6min) Aspiration 2 times 30 seconds interrupted by 5 minutes under V0 Aspiration 20 seconds then 3 minutes under V0 then aspiration 40 seconds 2.6 2.7 2.7 Table 2

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

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

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

[0067] A new cyclic phase begins after braking.

[0068] [Fig.6] shows a situation in which the speed V drops below V0. In this example, which initially resembles that of [Fig.5], at a time T0 during braking, the speed drops below the threshold V0. At this time, the suction becomes inactive, despite the fact that braking is in progress. After braking, in the case illustrated, 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), the suction is by default cyclical but that an activation of the brake makes the suction a priority, but also that no suction is carried out, regardless of the actuation or non-actuation of the brake, when the speed of the vehicle 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

Claims

1. Vehicle (1) comprising at least one disc brake (2) comprising: - a pair of linings (10, 12) having an element (44, 54, 64) for collecting braking particles; and - particle suction means (22, 24, 26) fluidically 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 lower than a threshold speed (V0).

2. Vehicle (1) according to claim 1, wherein the threshold speed (V0) is between 20 km / 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 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.

4. Vehicle (1) according to 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 one of claims 1 to 3, in which 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 activation of the brake (2) or until a few seconds after the end of activation of the brake (2).

6. Vehicle (1) according to one of claims 1 to 5, in which each collection element is a groove (44, 54, 64), optionally a peripheral groove (54) entirely surrounding the lining.

7. Method (100) for operating a vehicle according to one of claims 1 to 6, the method comprising the reception (110) of 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 maintain the suction means (22, 24, 26) inactive when the speed (V) of the vehicle (1) is lower than a 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) of 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 (T1) 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. Method (100) according to one of claims 9 to 12, in which the ratio between the first duration (T1) and the second duration (T2) is between 1 / 3 and 1 / 10.

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

14. Method (100) according to 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 activation of the brake or a few seconds after the end of the activation of the brake.

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

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