PROCEDURE FOR MANAGING A VEHICLE'S PASSAGE THROUGH A WASH TUNNEL

Abstract

The invention relates to a method for delaying the loss of hydraulic pressure supplying a locking device (PkLk) of a motor vehicle's transmission, in order to leave said vehicle in a car wash tunnel. The method comprises: - placing the gear lever in the 'N' position; - a selective maneuver performed by the driver to activate a request to delay the locking of the locking device; - switching off the ignition; - starting at least one initial time delay (Tp1) from the ignition switch; - maintaining hydraulic pressure and holding the locking device in the unlocked position until an interruption condition occurs, which is triggered by the expiration of the first time delay, or if the ignition is restored, or if the lever is placed in a position other than 'N'. Figure 5

Description

Title of the invention: METHOD FOR MANAGING A VEHICLE'S PASSAGE THROUGH A WASH TUNNEL

[0001] The invention relates to a method for managing the passage of a motor vehicle through a washing tunnel.

[0002] The wash tunnel is equipped with a mobile towing skid for moving vehicles along the washing process inside the tunnel. In practice, one of the wheels of the vehicle to be washed is placed on the towing skid at the entrance to the wash tunnel. Most often, this is a front wheel of the vehicle, for example, the front left wheel for left-hand drive vehicles.

[0003] We are interested here in vehicles equipped with a dual-clutch automatic transmission, which are usually equipped with a transmission locking device, equivalent to a 'P' function in a conventional automatic transmission, the transmission locking device having an automatic operating mechanism.

[0004] The gearbox control lever may in some cases be a physical lever with four distinct mechanical positions, but here we consider in particular the case of so-called "impulse control" gear levers, that is to say with a single stable mechanical position and at least two unstable positions, one forward and one backward, which is complemented by a visual feedback on the lever itself and on the dashboard.

[0005] We are interested here in hybrid vehicles in which mechanical power produced by an internal combustion engine can be delivered to the wheels simultaneously or independently of electromechanical power delivered by an electric machine also arriving at the wheels via a transmission which combines thermal power and electrical power.

[0006] It is possible that the hybrid vehicle may be of the plug-in hybrid type. A mild hybrid vehicle can operate in zero-emission mode for short distances.

[0007] In the illustrated example, the thermal and electrical power are delivered to the same axle. However, it is not impossible to have the thermal power delivered to the front axle (front axle) and the electrical power delivered to the rear axle (rear axle).

[0008] Optionally, the vehicle of interest can be equipped here with an electromechanical parking brake, replacing the conventional handbrake, with automated main operation, hence here named 'EPB' for 'Electronic Parking Brake'.

[0009] The powertrain has two main states: inactive or active.

[0010] In the inactive state, which will also be called 'APC OFF', the powertrain does not deliver any torque on the output shaft to the wheels.

[0011] In the active state, which will also be called 'APC ON', the powertrain is ready to deliver torque on the output shaft to the wheels, or even actually delivers non-zero torque on the output shaft to the wheels.

[0012] The term 'APC' is an acronym for After Ignition and designates an electrical state of the vehicle's overall electrical architecture. The vehicle must be in the 'APC ON' state for the internal combustion engine to operate.

[0013] The transition from 'APC ON' to 'APC OFF' is referred to here as "ignition off". The transition from 'APC OFF' to 'APC ON' is referred to here as "ignition on".

[0014] The switching on and switching off of the contact is controlled either by a rotary key switch as is used in all motor vehicles manufactured up to the 2000s, or in a modernized version by a pulse-type push button which allows the operating cycles and in particular the APC ON and OFF contact transitions to be managed via a control unit.

[0015] Whether with a rotary key switch or with a pulse push button, vehicles equipped with recent dual-clutch gearboxes have an automatic park function when the ignition is switched off (i.e. transition from 'APC ON' to 'APC OFF').

[0016] If the vehicle is equipped with an EPB electronic parking brake, then after switching off the ignition, this parking brake is also engaged, in addition to the transmission being locked by the P position locking device.

[0017] However, when the vehicle has to go through a washing tunnel, it must be and remain in freewheeling configuration, so the transmission locking device must not be engaged.

[0018] But, in the case of a control device of the impulse lever type, even if the driver wishes to leave the lever in the N position, the control system engages the locking device shortly after the contact is cut off.

[0019] Therefore, when the driver wishes to drive their vehicle through a car wash tunnel, it is imperative that the transmission locking device remain unlocked, and if the vehicle is equipped with an EPB electronic parking brake, then this parking brake must remain released. Otherwise, the forced traction of the vehicle by means of the tunnel's movable traction shoe may cause mechanical damage to either the vehicle or the movable shoe system.

[0020] There therefore remains a need to propose a solution for passing a motor vehicle through a washing tunnel, ensuring that the vehicle's transmission is maintained in freewheel mode for the necessary time.

[0021] In this context, the present invention proposes a method for delaying the loss of hydraulic pressure supplying a transmission locking device of a motor vehicle, in order to leave said vehicle in a car wash tunnel, the vehicle's transmission comprising a dual-clutch gearbox, characterized in that the method comprises: a- placing the gear lever in the 'N' position, b- a selective maneuver performed by the driver, in order to activate a request to delay the locking of the locking device until the next ignition switch-off, c- switching off the ignition, d- starting at least a first time delay, from the ignition switch-off, e- maintaining hydraulic pressure at a level above a first pressure threshold and maintaining the locking device in the unlocked position at least until an interruption condition occurs,The interruption condition is met upon expiry of the first time delay, or if the contact is restored ('APC ON'), or if the gear lever is placed in a position other than 'N'.

[0022] Thanks to the provisions promoted above, it is possible to access a special operating mode compatible with the passage of the vehicle through a washing tunnel.

[0023] Advantageously, the shutdown of the hydraulic system is delayed, and sufficient pressure is maintained in the hydraulic circuit that supplies the transmission locking device, so that this locking device remains unengaged, i.e. remains unlocked.

[0024] It is noted that the particular operation proposed is in reality an exception to the general operation which seeks to apply, following a break in contact (or shortly thereafter), an automatic engagement of the transmission locking device, subject where necessary to the verification of other safety conditions such as the speed equal to 0.

[0025] It is noted that the locking device is powered via a hydraulic medium, i.e. a hydraulic fluid under pressure supplied by a hydraulic system.

[0026] According to one embodiment, the locking device engages if the hydraulic pressure is absent or too low.

[0027] It is understood that the first time delay is aborted if the contact is restored (APC ON) before the end of the first time delay.

[0028] According to one embodiment, it is provided that if the interruption condition is met by the expiration of the first time delay, then the blocking device is placed in locked position and furthermore the hydraulic pressure is no longer maintained and drops (gradually) to zero.

[0029] Thanks to this time delay, the locking mechanism is eventually engaged after the time delay expires, even if the driver does not retrieve their car at the end of the wash sequence. In other words, the transmission is not left in neutral indefinitely.

[0030] Furthermore, this locking engagement makes it possible to meet a security need to immobilize the vehicle for tamper-proof and anti-theft functions.

[0031] According to one embodiment, the first time setting is a calibrable parameter between 10 minutes and 20 minutes, preferably between 14 min and 17 min.

[0032] We thus choose a slightly longer time delay than the envelope duration of known washing sequences, knowing that tunnel washing sequences last on average between 8 min and 14 min.

[0033] According to one embodiment, the transmission locking device takes the form of a movable finger in selective interaction with a gear of the transmission.

[0034] According to one embodiment, said finger, also called the "parking finger," is returned by an elastic element to the locking position, while the supply of hydraulic pressure moves the parking finger away from the locking position. In other words, the engagement of the parking finger occurs passively due to a lack of pressure.

[0035] According to one embodiment, the hydraulic pressure is generated by a hydraulic system comprising a hydraulic pump, and optionally a hydraulic accumulator. The hydraulic system supplies, in particular, the gearbox clutches, but also the transmission locking device.

[0036] According to one embodiment, the selective maneuver consists of a particular sequence involving a pulse selector for controlling the gearbox, the brake pedal and a device for starting and stopping the engine, either a push button or a rotary key switch.

[0037] This is a specific maneuver that cannot be performed accidentally. This maneuver is described in the owner's manual and in the tutorials on the vehicle's multimedia screen. This selective maneuver is compatible with a vehicle with a conventional key or a keyless vehicle with a one-touch start button ('Start / Stop Engine').

[0038] According to one embodiment, the method may further include a step of providing audible and / or visual feedback on a display to confirm to the user that the selective maneuver has been correctly taken into account.

[0039] The user can thus have confirmation that the selective maneuver has been correctly carried out, or that, on the contrary, it has failed.

[0040] According to one embodiment, a second time delay is provided, which is started from the moment the contact is cut off, with a shorter duration than the first time delay, said second time delay causing a maintenance of the hydraulic pressure to facilitate a possible restart of the engine by means of the electric machine associated with the gearbox, said second time delay being extended by the first time delay if a washing tunnel mode has been called and confirmed.

[0041] This second delay is present if the start of the internal combustion engine is obtained via the intervention of the electric machine present in the gearbox, in which case the main clutch KO must be closed which requires the maintenance of hydraulic pressure for a few tens of seconds after the ignition is switched off, in order to react without delay to any need for a rapid restart by the driver.

[0042] According to one embodiment, the second time delay is a calibrable parameter between 40 seconds and 80 seconds, and forms a cancellation window for the washing tunnel mode.

[0043] This value is a compromise between a duration sufficient to meet any need for rapid restart of the driver and a duration that is too long which could be perceived as an untimely event.

[0044] According to one embodiment, the vehicle is left, for the washing sequence, on a moving skid arranged at the base of the washing tunnel. The said tractor shoe can be attached to a loop chain, or to a conveyor or a conveyor belt.

[0045] The invention further relates to a hybrid vehicle comprising an internal combustion engine and a transmission with an electrified dual-clutch gearbox, and at least one control unit configured to implement the method as described above.

[0046] The invention will be further detailed by describing non-limiting embodiments, and based on the accompanying figures illustrating variants of the invention, in which: [Fig.1] schematically illustrates a vehicle passing through a car wash tunnel; [Fig.2] represents an example of the electrical and mechanical architecture of a hybrid vehicle with a dual-clutch transmission in which the present invention is implemented; [Fig.3] schematically illustrates a functional block diagram giving an example of a system implementing the present invention; [Fig.4] represents an example of a timing diagram in the case of a contact cut-off sequence, with washing and expiration of the first time delay; [Fig.5] represents another example of a timing diagram in the case of a contact break sequence, with washing and re-establishing contact before the end of the first time delay; [Fig.6] represents another example of a timing diagram in the case of a contact cut-off sequence, without execution of the particular sequence for the purpose of passing through the wash tunnel, but with temporary maintenance of hydraulic pressure in anticipation of a possible rapid restart by the driver.

[0047] In the various figures, the same reference numerals designate identical or similar elements. For the sake of clarity, some elements are not necessarily shown to scale.

[0048] Figure 1 represents a TLV wash tunnel configured to wash VH vehicles during their progressive passage inside the TLV wash tunnel. The progressive passage consists of moving the vehicle forward gradually, while rotating brushes and air nozzles act simultaneously on the vehicle.

[0049] The vehicle in question can be a sedan, a pickup truck, a coupe, a van, etc.; there is no limitation on the type of vehicle. The vehicle can be 4x4 or 4x2.

[0050] The wash tunnel is equipped with a mobile SBT towing skid to move vehicles along the washing process inside the tunnel. In practice, one of the wheels of the vehicle to be washed is placed on the towing skid at the entrance to the wash tunnel. Most often this is a front wheel of the vehicle, for example the front left wheel for left-hand drive vehicles.

[0051] The SBT traction shoe can be attached to a loop chain, conveyor, or moving walkway. When the wash tunnel is in operation, the traction shoe slowly moves from the entrance to the exit and pulls one vehicle wheel, while the other vehicle wheels roll freely on the floor. Any other means of moving the vehicle forward, such as a cleat or a push stop, can be used instead of the aforementioned traction shoe.

[0052] A general diagram of a hybrid type traction chain is now described with reference to [Fig.2].

[0053] In the illustrated example, the hybrid drivetrain powers the front axle. Of course, the hybrid drivetrain could also power the rear axle. It is also possible to have the drivetrain shown here coupled to one axle and a second electric motor coupled to the other axle.

[0054] The traction chain includes an internal combustion engine designated ENG and identified 1, a transmission designated TR, which includes a gearbox BV and an electric machine designated ME and identified 2.

[0055] The output shaft 56 of the gearbox BV is connected to the wheels of the relevant axle via a differential Diff and wheel shafts 58, as known per se and therefore not described in detail. It is noted that only one wheel 59 and only one wheel shaft have been represented in [Fig.2].

[0056] The internal combustion engine 1 is controlled by a first electronic computer 10.

[0057] In the example illustrated here, the electric machine 2 is also controlled by the electronic computer 10, but of course it could be controlled by a separate computer.

[0058] The phases of the electric machine are controlled via an inverter 22. The electric machine 2 can act alternately as a motor or a generator. The electric machine 2 is operated as a generator, particularly during regenerative braking. The rest of the time, the electric machine is used as a primary or auxiliary traction motor, and also to start the internal combustion engine 1, or is not used in certain phases.

[0059] The transmission includes a main clutch KO, whose function is to selectively couple the engine output shaft with the primary transmission shaft 55. The primary shaft 55 is arranged downstream of the main clutch KO and forms the input shaft of the gearbox BV.

[0060] This KO main clutch is open when the internal combustion engine is stopped and the vehicle is traveling in zero emission mode.

[0061] When the internal combustion engine is running and needs to provide traction power to the wheels, then the main clutch KO is closed.

[0062] The transmission includes on its primary shaft 55 a gear coupled to the electric machine 2, via where appropriate a reduction stage 54. In the example illustrated here, the coupling between the electric machine and the primary shaft is permanent.

[0063] In the illustrated example, the BV gearbox is a mechanically type electrified dual-clutch gearbox, and the gearbox control is robotized.

[0064] The gearbox comprises a first clutch K1 serving a first half of the gearbox and a second clutch K2 serving a second half of the gearbox. According to the example given here, the first half of the gearbox carries the odd-numbered gears, e.g. 1, 3, 5, and 7. The second half of the gearbox carries the even-numbered gears, e.g. 2, 4, and 6.

[0065] The first clutch K1 and the second clutch K2 are arranged coaxially in the gearbox, although symbolically represented on two separate axes in [Fig.2] for clarity of exposition.

[0066] In the illustrated example, the gearbox is associated with a hydraulic unit 4 which includes a hydraulic pump P supplying pressurized oil on the one hand to lubricate the components of the gearbox and on the other hand for the control of the clutches KO, Kl and K2.

[0067] The oil pump P is driven by a specific electric motor 40, independently of the operation of the internal combustion engine.

[0068] Optionally, a hydraulic accumulator R may be provided.

[0069] The gearbox is operated by electric actuators, e.g. fork displacement cylinders, clutch control cylinders KO, Kl and K2, powered by pressurized oil from the hydraulic unit 4.

[0070] In the illustrated example, the alternator 57 supplies electrical energy to the NW1 network with a nominal voltage of 48 Volts connected to a first battery 51. It is noted that the nominal voltage of the first network could be different from 48 volts.

[0071] In addition to the alternator, for certain vehicle configurations, a conventional starter in selective mechanical coupling with the engine crankshaft may be provided.

[0072] A DC / DC converter designated 5 is provided which supplies a second network NW2 with a nominal voltage of 12V connected to a second 52 (conventional 12 volt battery) as well as to a plurality of electrical equipment operating under 12 Volts as known per se, including the specific electric motor 40 of the hydraulic group 4.

[0073] The first battery 51 may be of the Lithium-Ion type. The first battery 51 may be recharged independently of the alternator present on the vehicle, by connecting it to a charging means from a source external to the vehicle. This is the configuration known as a "plug-in hybrid". The electrical energy stored in the first battery 51 is used by the electric motor.

[0074] The transmission locking device is designated PkLk; it comprises a gear 61 fixed for rotation with a rotating element of the transmission, in the illustrated example this being the differential ring gear. The transmission locking device includes a parking finger 62, movable (here radially) between a position engaged in the gear 61 and a disengaged position, without mechanical interference with the gear. Any other hydraulically controlled mechanical locking system may also be suitable.

[0075] According to one embodiment, the parking finger 62 is returned to the locked position by an elastic element, for example, by a spring. Conversely, the application of hydraulic pressure moves the parking finger away from the locked position. Thus, the parking finger engages passively due to a lack of pressure. It should be noted that the parking finger 62 cannot engage if the wheel 61 is rotating.

[0076] Furthermore, some vehicles are equipped with an automated parking brake, here referred to as EPB for 'Electronic Parking Brake'. This automated parking brake (or automated parking brake) replaces the conventional handbrake. Generally, this automated parking brake is engaged each time the ignition is switched off, or shortly after the ignition is switched off, without excluding a combination of conditions known in themselves and therefore not detailed here. The active components of the automated parking brake act on the wheels, particularly and generally on the rear wheels (although symbolically represented in [Fig.2] on the single wheel shown).

[0077] For the automated parking brake, a manual control button EPB Sw is provided, delivering information marked FP (see [Fig.3]).

[0078] PRND lever and other inputs

[0079] Regarding the gearbox control lever, we consider here the case of gear levers known as "pulse control", that is to say with a single stable mechanical position and two, three or four unstable positions, one or two forward (+) and one or two backward (-), as illustrated by the pulse button marked 87 in [Fig.3].

[0080] According to a particular example, the impulse control lever has four unstable positions: two forward positions with a basic stroke and an overstroke, and two rearward positions with a basic stroke and an overstroke. For example, from position D, if the user activates the basic stroke, the gearbox switches to position N, whereas if the user directly activates the overstroke, the gearbox switches directly to position R.

[0081] In other words, a simple impulse on the basic stroke changes the gearbox by one step (D->N or N->R or N->D or R->N), the use of the overstroke allows skipping a step, in particular to switch quickly between D and R.

[0082] The impulse lever is complemented by a visual feedback on the lever itself and on the dashboard, representing the actual effective position P, R, N, D, without excluding a manually controlled position.

[0083] We are now interested in the starting and stopping of the internal combustion engine 1, as well as the switching on and switching off of the ignition.

[0084] For this purpose, a start button, also called the 'start engine' button 88 (or simply 'start'), is provided, as shown in [Fig. 3]. This start button can be generically called the 'starting device'. In an alternative embodiment, a conventional ignition switch 81 can be used to initiate the starting sequence, as well as to switch the ignition on or off.

[0085] The vehicle is equipped in a known manner with a brake pedal 8 with a brake pedal sensor 84. The contact used materializes the fact that the brake pedal is substantially depressed.

[0086] Continuing on [Fig.3], the vehicle is equipped with a multifunction display 9. The electromotor unit computer (called CMM) is identified 10 while the dual-clutch transmission computer (called TCU) is identified 7.

[0087] It is also provided in a general multifunction computer called BSI (Intelligent Service Box). This multifunction BSI computer receives most of the logic inputs necessary for the operation of the system.

[0088] The various computers of the vehicle communicate with each other and exchange information by means of a multiplexed bus 44, for example a CAN bus.

[0089] Selective maneuver for tunnel washing mode

[0090] An example of a WTM selective maneuver is described below to request the delayed shutdown of the hydraulic functions and consequently to keep the vehicle in freewheel mode. The WTM selective maneuver begins with the vehicle at a standstill (zero speed), engine running, foot on the brake, and the gear selector in neutral (N).

[0091] Within 5 seconds, the following operations must be carried out.

[0092] Press and hold the brake pedal down, then follow this order:

[0093] if the engine is switched off and the impulse selector is moved forward or backward. s2 release the brake pedal then turn the ignition back on. s3 Foot on the brake, press the electric parking brake control to release it. 4s Release the brake pedal, turn off the ignition.

[0094] It should be noted that if the vehicle is equipped with a conventional handbrake, in steps s3 and s4 above the handbrake status switch is used instead of the automated parking brake status switch.

[0095] Another example of selective maneuvering can be achieved by means of user interaction on the vehicle's multifunction display 9 (e.g. touchscreen).

[0096] Figures 3 to 5 illustrate, via respective chronograms, three different scenarios, the first two concerning an actual passage through a washing tunnel.

[0097] As illustrated in figures 3 to 5, the selective maneuver is identified WTM, and a first time delay Tpi is started at the time of the contact being cut off.

[0098] The key cut-off request corresponds to pressing the SSB start stop button.

[0099] The state of the contact ('APC') on the vehicle is shown on the third line from from the top. The mode selected ('PRND') by the gear lever is shown on the fourth line.

[0100] At time tl, the driver selects the neutral mode N using the gearbox control lever.

[0101] At time t2, the driver performs the required selective maneuver, either by manipulating the gearshift lever and brake pedal, or by interacting with the touchscreen. This selective maneuver WTM triggers a request to enter a tunnel wash mode, which in practice is a request to delay the interruption of the hydraulic unit until the ignition is switched off.

[0102] It is noted, in view of the example provided above, that the selective maneuver can itself include a cutting off and a re-establishing of the contact.

[0103] At time t3, we have the request for final contact cut-off.

[0104] At time t4, we have the ignition cut-off (APC OFF) which launches the first the time delay mentioned above, Tpi, is of approximately 15 minutes.

[0105] On [Fig.4], the first time delay elapses completely until its expiry, at time t6. The first computer 10 or the BSI then decides to interrupt the maintenance of the hydraulic pressure and cuts off the supply to the hydraulic pump via the stopping of the engine 40, at time t7.

[0106] This results in the engagement of the park finger 62 in the toothed wheel 61 of the transmission and consequently a locking of the transmission.

[0107] In [Fig. 5], the wash is shorter, and the driver returns to the driver's seat of his car before the expiry of the first 15-minute timer. The driver turns the ignition back on at time t5. The driver starts the engine and / or the electric machine and selects drive mode D or reverse R or even P on the gear selector of the gearbox and then moves the vehicle.

[0108] Of course, when the ignition is switched on again, the first timer is interrupted and aborted. The hydraulic unit continues to operate without interruption during this sequence. The hydraulic unit will be switched off after the next ignition switch-off, immediately or shortly thereafter.

[0109] It is noted that in figures 4 and 5, the automated parking brake EPB remains released while the first time delay elapses, i.e. in the OFF state.

[0110] After the expiration of the time delay Tpi on the [Fig.4], at time t6, the automated parking brake can be engaged or alternatively remain disengaged according to the strategy implemented in the management of the vehicle's electrical network.

[0111] In figures 5 and 6, at time t4, we have the contact cut-off (APC OFF) which launches on the one hand the first time delay mentioned above Tpi with a duration of approximately 15 minutes and on the other hand a second time delay Tp2 with a duration of approximately 60 seconds.

[0112] This second time delay Tp2 is present for configurations where the internal combustion engine is started via the intervention of the electric machine 2, in which case the main clutch KO must be closed, which necessitates maintaining hydraulic pressure after the ignition is switched off, in order to react immediately to any need for a rapid restart by the driver. Indeed, closing the main clutch KO requires the presence of hydraulic pressure.

[0113] At time t8, the second time interval Tp2 is extended by the first time interval if a wash tunnel mode has been called and confirmed. Even if the hold function for short-delay restart has priority in the logics of the software of the respective computers, at time t8, it is the mode of passage through the washing tunnel which takes over and continues to maintain the hydraulic pressure to keep the neutral mode of the gearbox for the entire duration of the washing or the time delay Tpi, as illustrated on the timing diagram of [Fig.5].

[0114] However, in the example of [Fig.6], the driver did not request the tunnel wash mode and consequently, the hydraulic pressure is interrupted at the expiry of the second time delay Tp2 without the first time delay taking over.

[0115] It is noted that, according to an optional embodiment, the second time interval Tp2 can create a window for canceling the tunnel wash mode. Indeed, if the driver operates the gear selector again during this window, then the tunnel wash mode is canceled, and an audible or textual notification is given to the driver on the multifunction display.

[0116] According to one embodiment, the first time delay Tpi is a calibrable parameter, between 10 minutes and 20 minutes, preferably between 14 min and 17 min.

[0117] According to one embodiment, the second timing Tp2 is a calibrable parameter, between 40 seconds and 80 seconds.

[0118] Of course, the preceding examples are given only as examples and are in no way limiting; a person skilled in the art may consider all reasonably accessible variations and combinations.

Claims

Demands

1. A method for delaying the loss of hydraulic pressure supplying a locking device (PkLk) of the transmission (TR) of a motor vehicle (VH), in order to leave said vehicle in a vehicle wash tunnel (TLV), the vehicle's transmission comprising a dual-clutch gearbox, characterized in that the method comprises: a- placing the gear lever in the 'N' position, b- a selective maneuver performed by the driver, in order to activate a request to delay the locking of the locking device until the next ignition switch-off, c- switching off the ignition, d- starting at least one first time delay (Tpi), from the ignition switch-off, e- maintaining hydraulic pressure at a level above a first pressure threshold and maintaining the locking device in the unlocked position at least until an interruption condition occurs,the interruption condition being met upon expiry of the first time interval or if the contact is restored or if the gear lever is placed in a position other than 'N', and characterized in that a second time interval is provided, starting from the breaking of the contact, with a shorter duration than the first time interval, said second time interval causing a maintenance of hydraulic pressure to facilitate a possible restart of the engine by means of the electric machine associated with the gearbox, said second time interval being extended by the first time interval if a wash tunnel mode has been called and confirmed.

2. The method according to claim 1, characterized in that if the interruption condition is achieved by expiry of the first time delay, then the locking device is placed in the locked position and furthermore the hydraulic pressure is no longer maintained and gradually decreases to zero.

3. A method according to any one of claims 1 to 2, characterized in that the first timing (Tpi) is a calibrable parameter between 10 minutes and 20 minutes, preferably between 14 minutes and 17 minutes.

4. A method according to any one of claims 1 to 3, characterized in that the transmission locking device takes the form of a movable finger in selective interaction with a gear of the transmission.

5. A method according to any one of claims 1 to 4, characterized in that the hydraulic pressure is generated by a hydraulic system comprising a hydraulic pump and optionally a hydraulic accumulator.

6. A method according to any one of claims 1 to 5, characterized in that the selective maneuver consists of a particular sequence involving a pulse selector for controlling the gearbox, the brake pedal and a device for starting and stopping the engine, either a push button or a rotary key switch.

7. A method according to any one of claims 1 to 6, further comprising an audible and / or visual feedback step on a display to confirm to the user that the selective maneuver has been correctly taken into account.

8. Method according to claim 1, characterized in that said second time delay is a calibrable parameter between 40 seconds and 80 seconds.

9. Hybrid vehicle comprising an internal combustion engine and a transmission with an electrified dual-clutch gearbox, and at least one control unit configured to implement the method according to any one of claims 1 to 8.

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