PARKING BARRIER CONTROL SYSTEM

Description

[0001] The invention relates to the field of gearbox controls for motor vehicles, and more specifically to the field of parking lock control which can be electrically controlled and associated with a gearbox, in particular an automatic gearbox.

[0002] We know of parking lock controls using a mechanical cable operated by the lever of an automatic gearbox, in the passenger compartment.

[0003] But gearboxes are increasingly electrified and automatic, and mechanical controls are being replaced by electric controls (“by wire”).

[0004] The parking lock actuation system must have at least one stable position, i.e. one that does not require electrical energy to last over time. Systems with a single stable position are known (monostable systems) and systems with two stable positions are also known (bistable systems).

[0005] The invention is an evolution of a monostable system, which in its nominal operation, according to the prior art, has a default position in which the parking lock is engaged and maintained. This default position is that reached in the absence of power supply to the actuation system.

[0006] A vehicle handling problem is encountered during the delivery of the gearbox to the final assembly plant. At this point, it is necessary to move the vehicle, but the gearbox and the parking lock actuation system are not powered. Manual access to the parking lock control is known to be tedious and requires a planned access path and manual grip. A tool may also be left in the vehicle. The production line is interrupted at each difficulty.

[0007] The problem also arises in various other life situations, including repairs or revisions.

[0008] Document DE102014104575_A1 discloses a parking lock with translationally movable coupling and actuating members, with coupling and actuating directions that are transverse to each other.

[0009] Document DE-A1-102010043257 discloses a parking lock control system for a vehicle with an automatic transmission, according to the preamble of claim 1.

[0010] Document WO-A1-2018192989, which constitutes the state of the art according to Article 54(3) EPC, discloses a parking lock control system for a vehicle with an automatic transmission.

[0011] To solve the problems mentioned above, a lock control system is proposed comprising a first actuator in motion between a first stable state in which a lock system is implemented, the first stable state being a state which does not require electrical or hydraulic energy to persist over time, and a first disengaged position in which the lock system is deactivated, and a second actuator in motion between a rest position in which the second actuator does not interact with the first actuator, and an active position in which the second actuator is forced against the first actuator, the first actuator comprising a first socket for a head of the second actuator which, when this second actuator is in the active position and its implementation is maintained, blocks the first actuator in the first disengaged position,the first actuator comprising a rod between a head for actuating the locking system and a cylinder for moving the rod and the head.,

[0012] The system is remarkable because the first actuator further comprises a second socket, shaped jointly with the head of the second actuator, to interact with it so as to block the first actuator in a second stable state in which the locking system is deactivated, the second stable state being a state which does not require electrical or hydraulic energy to persist over time, the first and second sockets being in the form of two notches provided at two distinct heights of the rod.

[0013] This provides a stable state of the parking lock, requiring no energy input, and in which the parking lock is disengaged.

[0014] Optionally and advantageously, the system can have the following characteristics: the first actuator is in translational movement in a first direction between the first stable state and the first disengaged position; the second actuator is in translational movement in a second direction between the rest position and the active position; the second stable state is reached by a stroke of the first actuator from the engaged position longer than that necessary to reach the first disengaged position; the first and second actuators are returned respectively to their first stable state and their rest position by springs; the first and second actuators are electrically or hydraulically operated.

[0015] The invention also provides a parking lock for a motor vehicle with automatic transmission comprising a control system as mentioned above.

[0016] The invention also provides a motor vehicle with an automatic gearbox comprising such a parking lock.

[0017] The invention will be better understood, and other aims, characteristics, details and advantages thereof will appear more clearly in the explanatory description which follows, made with reference to the appended drawings given solely by way of example illustrating an embodiment of the invention and in which: There figure 1 is a view of the system in a parking brake engaged position; the figure 2 is a view of the system in a parking brake unlocked position with electricity supplied to the actuators; the figure 3 is a view of the system in an original stable position of unlocking the parking brake without electricity supply to the actuators; the figure 4 is a schematic view of the system states.

[0018] In figure 1 a parking lock control system according to the invention is shown, in a first position.

[0019] This control system comprises a first actuator 1 in translational movement in a direction D1, and a second actuator 2 also in translational movement in a direction D2.

[0020] These two actuators are electric (or hydraulic) actuators, and their translational movements are transverse to each other, and more precisely perpendicular to each other.

[0021] They both comprise control rods directed in the translation direction. The control rod of the first actuator 1 is referenced 10 and the control rod of the second actuator 2 is referenced 20. Each of these rods comprises a head at its free end. The head of the rod 10 of the actuator 1 is referenced 11 and has a function of actuating the parking brake, and the head of the rod 20 of the actuator 2 is referenced 21 and has a function of interacting with the rod 10 for its blocking.

[0022] The actuator 1 further comprises a cylinder 18 with return means which are constituted by a spring 19.

[0023] The actuator 2 comprises a cylinder 28 with return means constituted by a spring 29.

[0024] Cylinders are either hydraulic cylinders or solenoid (electromagnetic) cylinders.

[0025] The control system comprises a finger 4, having a structure of a cam on which the head 11 presses to make it move in translation in a direction perpendicular to the direction of translation of the rod 10 of the first actuator 1.

[0026] Finger 4, by its translational movement, locks or releases parking lock 3.

[0027] In the position of the control system shown in figure 1 , each of the two actuators 1 and 2 is not supplied with energy, and therefore adopts its rest position, defined by the elastic, spring-type return means with which they are equipped. The first actuator 1 is in the stable position, or first stable state ES1. The second actuator 2 is in the rest position PR.

[0028] It follows from this situation that the first actuator 1 is moved towards the finger 4, which corresponds to its rest position, that the actuator 2 is moved away from the actuator 1 and more precisely from its rod 10, which corresponds to its rest position.

[0029] Consequently, the actuator 2 has no influence on the position of the actuator 1, which is free, and which pushes the finger 4, resulting in the locking of the parking lock 3 and the immobilization of the stationary vehicle, which can thus remain parked for a long time without consuming electrical energy (or hydraulic energy depending on the type of actuator) for the actuator 1. The return energy of the spring 19 is sufficient for the engagement and maintenance of the parking lock.

[0030] In figure 2 , at the request of the user of the motor vehicle, the first actuator 1 and the second actuator 2 are both supplied with energy and move, respectively for the actuator 1 by moving away from the finger 4, towards the left of the figure, following a stroke C1, and for the actuator 2 by moving closer to the rod 10 of the actuator 1, towards the top of the figure. The second actuator 2 is forced against the first actuator 1.

[0031] A first consequence of these movements is that the parking brake 3 is deactivated (the actuator 1 is in a disengaged state or position ED), and the vehicle can be set in motion to travel on the road, propelled by its powertrain and steered by the driver.

[0032] A second consequence of these movements is that the head 21 of the rod 20 of the actuator 2 enters a catch 15 in the form of a notch provided on the surface of the rod 10 on the side facing the actuator 2. The latter reaches an active position PA.

[0033] The insertion of the head 21 into the socket 15 has the effect of blocking the movement of the rod 10 of the actuator 1. This blocking is a securing effect of the deactivation of the parking brake. Indeed, in the event of failure of the excitation circuit of the first actuator 1, the second actuator 2 would hold the first actuator 1 in position.

[0034] On the other hand, in the event that the power supply to the two actuators 1 and 2 is cut off, for example for parking, the head 21 of the actuator 2, under the effect of the spring 29, withdraws from the socket 15 which does not offer it any resistance and the actuator 1 is then free to return to the position of the figure 1 , which it does spontaneously by the effect of spring 19, then engaging parking brake 3.

[0035] In figure 3 , the parking lock control system presented in the previous figures is shown in an original locked position allowing the actuators to be deactivated.

[0036] Actuator 1 has followed relative to the position in which it is shown in figures 1 et 2 a translation to the left bringing it into a position even further away from finger 4 than that represented in figure 2 . The race is a C2 race from the position of the figure 1 , with C2 > C1.

[0037] After the actuator 1 has followed this stroke and thus reached an intermediate position PI1, the actuator 2 is supplied with energy so that its head 21 is inserted into a socket of the rod 10 of the actuator 1. It reaches its active position PA, already described in connection with the figure 2 .

[0038] Taking into account the additional travel performed by the actuator 1 so that it moves away from the parking finger 4, the head 21 is inserted into a socket 16 on the lateral surface of the rod 10 located between the socket 15 and the head 11, on the side of the actuator 2 and having the shape of a notch.

[0039] The particularity of the socket 16, compared to the socket 15, is that it is shaped, together with the head 21, so that in the event of the power supply to the actuator 1 and the actuator 2 being removed, a new effect is obtained.

[0040] As a reminder, in the event of the power supply to the two actuators being removed, the actuator 1 is pushed back by its return means (spring 19) towards the finger 4, and the actuator 2 is returned by its return means (spring 29) so as to move away from the rod 10.

[0041] The new effect is that socket 16 holds head 21, which is not the case with socket 15 in the configuration of the figure 2 . The two actuators hold each other in the positions of the figure 3 , namely the stable state ES2 and the active position PA.

[0042] Thus, it is easy in certain situations to put the parking lock in a specific configuration with the disengaged parking lock remaining in this position stably without energy input.

[0043] This feature can be used for certain maintenance operations as well as during delivery of the gearbox to the vehicle assembly plant.

[0044] To ensure the proper functioning of the system, it is best to once the position described in figure 3 reached with the actuators supplied with energy (position PI1), first, cut off the power supply to the actuator 1, so that the plug 16 is properly engaged with the head 21 thanks to the return means of the actuator 1, then only in a second step cut off the power supply to the actuator 2, this removal of the power supply to the actuator 2 having no consequence since the head 21 is retained by the plug 16. The second stable position ES2 is reached.

[0045] It is specified that to leave this specific position and return to nominal mode as represented by the figures 1 et 2 , the solution is to re-supply power to actuators 1 and 2 (or only actuator 1), this allowing the rod 20 of actuator 2 to be released, more precisely its head 21 which leaves the socket 16 and its engagement with it so that actuator 2 can return by itself to the rest position, thanks to its return means. An intermediate position PI2 is thus reached. Once this is done, the complete return to the nominal unlocked position (state ES1) is done by cutting off the power supply to actuator 1.

[0046] Thus, an additional stroke C2 of the actuator 1 was used, which is used only under certain conditions, and an additional blocking system defined by the socket 16 to block the actuator 1 with the control in the disengaged position, or second stable state ES2.

[0047] In figure 4 the evolutions of the system have been represented.

[0048] The nominal positions of this are represented by ES1 (stable state n°1, represented in figure 1 , and in which the lock is set) and ED (disengaged state, represented in figure 2 , in which the actuators are kept powered). The stroke of the actuator 1 between ES1 and ED is a distance C1, parallel to the rod 10, under the effect of the actuation of the two actuators 1 and 2. The passage from ES1 to ED is naturally reversible by a reverse movement, caused by the return means of the actuators 1 and 2, after stopping the electrical (or hydraulic) actuation of the actuators 1 and 2.

[0049] From state ES1, a stroke C2 of actuator 1, under the effect of actuation of actuator 1, parallel to rod 10 and longer than stroke C1 makes it possible to reach an intermediate position PI1, from which actuation of actuator 2 makes it possible to reach a stable state ES2, in which the energy supplies of the two actuators can be interrupted, starting with that of actuator 1.

[0050] Then, by restoring the power supply to actuator 1, it is possible to reach an intermediate position PI2, from which the interruption of the power supply to actuator 1 makes it possible to return to the stable state ES1, corresponding to the locking position.

[0051] It is thus possible to set up a gearbox which, under particular conditions, can have a stable operating mode with a stationary system despite the absence of energy input (state ES2), which can of course be easily brought back to a classic operation with automatic engagement of the parking lock in the event of an energy cut (state ES1) as is the case from the configuration of the figure 2 . Eventually, it is possible to move from ES2 to ED, in a controlled manner.

[0052] The invention therefore makes it possible, without the need to add additional components, to meet the needs corresponding to the life situations encountered without requiring any particular manual actions from the user.

[0053] Remarkably, the solution allows for the delivery of an unlocked automatic gearbox in ES2 condition. It does not require a holding tool to do this. It also allows, during the vehicle's lifetime and for a maintenance operation, for example, to return the gearbox to the unlocked position, as in delivery mode, while removing the power supply to the actuators.

Claims

1. A lock control system comprising a first actuator (1) moving between a first stable state (ES1) in which a lock system (3) is implemented, the first stable state (ES1) being a state which does not require of electrical or hydraulic energy to last over time, and a first disengaged position (ED) in which the lock system (3) is deactivated, and a second actuator (2) moving between a rest position (PR) in which the second actuator (2) does not interact with the first actuator (1), and an active position (PA) in which the second actuator (2) is constrained against the first actuator (1), the first actuator (1) comprising a first socket (15) for a head of the second actuator (21) which when this second actuator (2) is in the active position (PA) and its implementation is maintained blocks the first actuator (1) in the first disengaged position (ED), the first actuator (1) comprising a rod (10) between a head (11) for the actuation of the system of lock (3) and a cylinder (18) for moving the rod (10) and the head (11), characterized in that the first actuator (1) further comprises a second socket (16), shaped, together with the head of the second actuator (2), to interact with the latter so as to block the first actuator (1) in a second stable state (ES2) in which the lock system (3) is deactivated, the second state stable (ES2) being a state which does not require electrical or hydraulic energy to persist over time, the first and second sockets (15, 16) being in the form of two notches provided at two distinct heights of the rod (10).

2. Lock control system according to claim 1, characterized in that the first actuator (1) is in translational movement in a first direction. (D1) between the first stable state (ES1) and the first disengaged position (ED).

3. Lock control system according to claim 1 or claim 2, characterized in that the second actuator (2) is in translational movement in a second direction (D2) between the rest position (PR) and the active position (PA).

4. Lock control system according to one of claims 1 to 3, characterized in that the second stable state (ES2) is reached by a stroke (C2) of the first actuator from the engaged position (ES1) longer than that required (C1) to reach the first disengaged position (ED).

5. Lock control system according to one of claims 1 to 4, characterized in that the first and second actuators (1, 2) are returned respectively in their first stable state (ES1) and their rest position (PR) by springs (19, 29).

6. Lock control system according to one of claims 1 to 5, characterized in that the first and second actuators are electrically or hydraulically operated.

7. Parking lock for motor vehicle with automatic transmission characterized in that it comprises a control system according to one of claims 1 to 6.

8. Motor vehicle with automatic gearbox characterized in that it comprises a parking lock according to claim 7.