FR3074122B1 - DEVICE FOR CONNECTING THE GROUND OF A VEHICLE COMPRISING AN ANGULAR POSITION DETECTION UNIT OF A WHEEL - Google Patents

Abstract

Device for connecting to the ground of a vehicle, comprising: - a wheel (10) of the vehicle, - a vacuum source, - a plurality of channels (30) arranged between the vacuum source and a tread of the wheel ( 10), - means for opening and closing the channels (30), arranged between the vacuum source and the tread to open or close an air passage in each channel (30), characterized in that the ground connection device further comprises an angular position detection unit (60) arranged to determine an angular position of the wheel (10), so as to control the opening and closing means for opening or closing independently each air passage as a function of the angular position of each channel (30).

Description

GROUND CONNECTING DEVICE

The present invention relates generally to a ground connection device mounted on a motor vehicle. Typically, the ground link designates elements, generally linked together, making a connection between the chassis of a vehicle and the terrain on which it evolves. A ground connection device can generally be composed of the following elements (variable depending on the type of vehicle): axle, steering, wheels (tires and rims), brakes, suspension, anti-lock safety ...

These components have a significant impact on the safety of the occupants, because of their direct influence on handling, and DE19952878 discloses a ground connection device with channels arranged on the tread of a tire and communicable with a vacuum source to improve grip, thereby increasing occupant safety. However, this system is inefficient and requires a significant source of vacuum, which increases the energy requirements to feed it, as well as the weight of the necessary structure.

An object of the present invention is to meet the drawbacks of the prior art mentioned above and in particular, first, to provide a ground connection device that improves the safety of the occupants effectively, without necessarily requiring a large or impressive energy reserve.

For this a first aspect of the invention relates to a ground connection device of a vehicle, comprising: - a wheel of the vehicle, - a vacuum source, - a plurality of channels arranged between the vacuum source and a tread of the wheel, means for opening and closing the channels, arranged between the vacuum source and the tread to open or close an air passage in each channel, characterized in that the device ground linkage further comprises an angular position detecting unit arranged to determine an angular position of the wheel, so as to control the opening and closing means for independently opening or closing each air passage according to the angular position of each channel.

The angular position detection unit makes it possible to independently control the opening / closing of each air passage whose end facing the channel tread contacts or comes close to the ground, so that the other channels (whose ends facing the tread are away from the ground for example) can remain plugged, to save the vacuum source, and reduce the leakage rate and the need for vacuum level. In other words, only the channel (s) whose end contacts (s) or is (are) in close proximity to the ground is (are) open (s), which limits the leakage rate which alters the vacuum level in the vacuum source. It then takes less energy and volume to maintain the vacuum level at the threshold required to have a proper or effective increase in adhesion.

Advantageously, the vacuum source comprises at least one main vacuum cavity arranged in the wheel, forming a vacuum reserve. Such a main cavity makes it possible to immediately supply the level of vacuum, close to the tread.

Advantageously, the wheel comprises a rim, and the main cavity under vacuum is arranged in the rim. This arrangement generally simplifies the structure of the ground connection.

Advantageously, the wheel comprises an intermediate cavity connected to each of the channels, and separated from the main cavity under vacuum by a communication mechanism. This intermediate cavity makes it possible to separate the vacuum source and the opening and closing means, which limits the risks of leakage and the stresses applied to the opening and closing means.

[0009] Advantageously, the communication mechanism comprises a pyrotechnic device.

Advantageously, the wheel comprises a tire, each channel is formed at least in part by a tube, the device comprising an inner carcass arranged in the tire and traversed by the tube of at least one channel. Such an internal carcass makes it possible to roll with a flat or deflated tire and to keep the structure of the channels integral, which makes it possible to benefit from the optimization of adhesion even with a deflated tire.

Advantageously, the ground connection device comprises a positioning structure of the inner carcass arranged to position the inner carcass relative to the tire and / or to a rim receiving the tire. Such a positioning structure makes it possible to guarantee the position and thus the function of the internal carcass.

Advantageously, the positioning structure of the inner carcass is arranged between the inner carcass and a rim and comprises at least one plunger and a cavity receiving the plunger which can slide in the cavity at each wheel turn. The sliding of the divers in the cavity makes it possible to limit the hyperstatism.

Advantageously, each of the plurality of channels is provided with a valve arranged at the tread and having a state at least partially closed before activation of the opening and closing means. Such a valve prevents impurities and / or water from entering the vacuum circuit, for example to prevent clogging the channels.

Advantageously, the valve is a cap disposed in each of the plurality of channels at the tread. It is possible to envisage a stopper, a film, a cover and / or a membrane.

Advantageously, the valve is formed by a well enclosing a chimney, an inner surface of the well is in communication on the tread and / or is exposed to an external pressure, and an outer surface of the well gives and / or is in communication with the channel and / or is exposed to pressure in the channel, and the well is arranged to release a chimney opening if the internal pressure reaches a pressure of 0.5 bar (a) lower than the external pressure, and / or if a pressure difference greater than 0.5 bar (a) is applied between the inner surface and the outer surface of the well.

In other words, each channel comprises at its end a tube receiving the operculum, an inner surface of the well being exposed to atmospheric pressure, and an outer surface of the well being exposed to a pressure in the channel, the well is arranged to release the cap if its inner surface is exposed to atmospheric pressure, and if the outer surface is exposed to an absolute pressure of less than 0.5 bar (a). In other words, the well is flexible and deforms sufficiently to release the seal as soon as a differential pressure between its inner surface and its outer surface exceeds 0.5 bar.

Advantageously, each of the plurality of channels is slidably mounted relative to a rim of the wheel. This arrangement makes it possible to avoid a hyperstatic assembly, to compensate for the deformations of the tire at each turn of the wheel.

[0018] Advantageously, each of the plurality of channels comprises an end integral or recessed with the tread.

Advantageously, each of the plurality of channels is normally closed before activation of the opening and closing means, activation decided after detection of an emergency situation. In other words, during the normal life situations of the vehicle, the opening and closing means do not work, the channels are not in communication with the vacuum source. During an emergency life situation (for example during an emergency braking initiated to avoid a collision ...), the opening and closing means are activated to put the channels whose end is in contact or very close to the ground in communication with the vacuum source. In other words, the ground connection device comprises a main valve which keeps the empty source of the channels isolated, as long as the vehicle is in a life situation that does not require increased adhesion.

Advantageously, the opening and closing means are arranged to control an opening of the air passage of each channel whose end is close to the ground, and / or to maintain an opening of the air passage. of each channel whose end is close to the ground.

Advantageously, an end of a channel is judged near the ground if it is in an angular sector of the wheel centered on a straight line passing through the center of the wheel and a point of contact between the wheel and the ground , and range of ± 10 ° around this line.

[0022] Advantageously, the opening and closing means are electrically controlled.

Advantageously, the opening and closing means are solenoid valves. Alternatively, pneumatic or mechanical valves (via a cam) can be provided.

[0024] Advantageously, each of the plurality of channels comprises a solenoid valve.

Advantageously, the ground connection device comprises a passive pumping unit arranged between a rigid portion of the wheel and a deformable portion of the wheel to create or maintain a vacuum level in the vacuum source during a taxiing. of the vehicle.

Advantageously, the passive pumping unit is formed by at least one piston linked to the tread, and arranged to slide in a liner bound to a rim, so as to form a vacuum chamber comprising at least one valve anti-return, making it possible to create or maintain a level of vacuum in the vacuum source during a running of the vehicle.

In other words, the ground connection device comprises at least one piston connected to the tread, and arranged to slide in a jacket so as to form a vacuum chamber comprising at least one anti-return valve, to create or maintain a vacuum level in the vacuum source while driving the vehicle. Such a piston, sliding in the chamber at each turn of the wheel due to the deformations of the tire, will create and / or maintain an adequate level of vacuum to then be able to increase the adhesion. This passive system takes advantage of tire deformations at each wheel revolution to generate a vacuum (such as a piston pump) without the need for power.

Advantageously, the piston is embarked on a channel.

Advantageously, the ground connection device comprises a control unit connected to: - the angular position detection unit for receiving a signal of angular position of the wheel, and - the opening and closing means, to send an open or close command signal, based on the received angular position signal.

A second aspect of the invention is a vehicle comprising at least one ground connection device according to the first aspect of the invention.

Other features and advantages of the present invention will appear more clearly on reading the following detailed description of embodiments of the invention given as non-limiting examples and illustrated by the accompanying drawings, in which: : [0032] Figure 1 shows a side view of a wheel forming part of a ground connection device according to the invention; [0033] FIG. 2 represents a sectional view of the wheel of FIG. 1; Figure 3 shows the view of Figure 2, with means for opening and closing the ground link device activated; Figure 4 shows the view of Figure 3, with a tire of the flat tire; [0036] FIG. 5 represents a variant of the implementation of FIGS. 2 to 4; FIG. 6 shows the view of FIG. 5 after half a turn of the wheel; Figures 7a and 7b show a variant of the implementation of Figures 2 to 4.

Figure 1 shows a side view of a wheel 10 formed by a rim 11 and a tire 12 which rolls on a floor 100, about an axis of rotation 13. To improve the adherence, it is intended to implant a plurality of channels 30 in the wheel 10, which open on the tread of the wheel 10 and can be connected to a vacuum source when the need arises (emergency braking if a collision is anticipated, or if a tire of the vehicle is brutally pierced ...).

For this purpose, the ground connection device therefore comprises the wheel 10, the channels 30, but, as shown in Figures 2, 3 and 4, the ground connection device also comprises a vacuum source formed in particular by a depressurized main cavity (for example by an electric vacuum pump) housed in the rim 11, an intermediate cavity 21 separated from the main cavity 20 by a wall 11b of the rim 11 and a communication mechanism 70, a solenoid valve 41 arranged at a first end of a tube 31 forming part of the channel 30, and a detection unit 60 comprising for example at least one sensor 61 and a plurality of targets 62 on the rim 11.

During a rotation of the wheel 10 shown in FIG. 1, the sensor 61 measures a rotation of the wheel 10 during the passage of each target 62 in front of its detection surface (it is possible in particular to provide a first sensor with a single target on the rim 11, and a second sensor with a plurality of targets on the rim 11, so as to know the angular position of the wheel 10, reset at each wheel revolution. a sensor of an anti-lock wheel device, or ABS). It is then possible to deduce for each channel 30 an angle α with a straight line passing through the center of the wheel 10 and a point of contact with the ground 100. The angular sensor can also be combined with an on-board attitude sensor. vehicle for more precision.

To save energy, the invention proposes to put in communication a channel 30 with the vacuum source only when the end facing the tread comes close to the ground 100. For this purpose, the solenoid valve 41 of a channel 30 is controlled to open an air passage in a seat or body 32 only when the channel 30 in question has an angle α which indicates contact or imminent contact with the ground 100. For example, it is possible to open the solenoid valve 41 only if the angle α is less than 10 °.

In detail, Figure 2 shows the ground connection device in a non-activated state, or a normal driving state. In other words, the system is in a life situation where there is no need for increased adhesion. As a result, the channels 30 are at atmospheric pressure, the main cavity 20 is isolated from the intermediate cavity 21 by a plug 72 of the opening device, the solenoid valve 41 is closed, and the channel 30 terminates in a well 32 closed by a cover 33 which prevents impurities from the road to enter the tube 31. The lid 33 may be a plug, or a simple membrane, or a film.

The tire also comprises an inner carcass 53 traversed by the tube 31, and held in position by a positioning structure 50 formed by plungers 51 sliding in cavities of the inner carcass 53 and driven by springs 52. This carcass internal 53 makes it possible to roll with a tire 12 flat or under-inflated, as will be explained in FIG.

Finally, due to the deformability of the tire 12, it is possible to mount the tubes 31 sliding in a portion 11c of the rim 11, because they must remain attached to the tread. A seal is provided between the tube 31 and the wall 11c of the rim 11.

FIG. 3 represents a life situation where it is necessary to increase the adhesion of the tire 12 to the ground 100. For this purpose, the plug 72 of the communication mechanism 70 has been destroyed by a pyrotechnic device 71, so as to put in communication the main cavity 20 with the intermediate cavity 21 (which may advantageously have a smaller volume possible, contrary to what represents Figure 3, not to scale at this level). Finally, for the channel 30 whose angle α is low (end in contact with the ground 100), the solenoid valve 41 is activated (an electric coil pushes down the piston of the solenoid valve 41 so as to open a passage air in the body 32 of the solenoid valve 41), so that the vacuum of the main cavity 20 sucks the cap 33 which releases the well 32, which puts the tread in depression with the ground 100.

The other channels 30 of the wheel 10 are not put in communication with the intermediate cavity 21, that is to say that their solenoid valve 41 remains in the position shown in FIG. 2. During the rotation of the wheel, each solenoid valve 41 is activated (open) when the channel 30 corresponding to the end arriving at ground level 100 and activated again (closed) when the end leaves the ground 100. This significantly limits the leakage rates, which allows to reduce the size of the main cavity 20, and / or to limit the size of a possible vacuum pump.

It can be seen in Figure 3 that the tube 31 has slid a little relative to the rim 11 and its wall 11c, due for example to the braking force which cup the tire 12.

Figure 4 shows the tire 12 with a puncture, caused by an orifice 80 in the right side. As a result, the pressure in the tire 12 is equal to the atmospheric pressure, so that the tire 12 collapses, but the inner carcass 53 avoids rolling flat, forming a support between the rim 11 and the tread. The plungers 51 are driven into the cavities of the inner carcass 53, and the tube 31 has slid again relative to the wall 11c of the rim 11. In summary, the inner carcass 53 preserves the structure of the channels 30, and driving with a tire that is under-inflated and / or somewhat sagging, but that still allows the ground-engaging device to be used again to provide increased grip with respect to the same tire that would be totally collapsed with the unusable ground-tie device .

FIG. 5 represents an alternative or an improvement of the implementation of FIG. 2. Indeed, a mechanism composed of a piston 91 anchored on the tube 31 via a rod has been added, to slide at each turn. wheel in a jacket formed by the walls 11a and 11b of the rim 11. Non-return valve communications are provided, including a communication 92 in the wall 11b to provide an anti-return communication with the main cavity 20. This architecture allows to create or maintain the vacuum level in the main cavity at each wheel revolution, as shown in FIG. 5 (low distance D1: recessed tire and end of channel 30 shown in contact with the ground) and FIG. D2 greater than D1: tire relaxed after half a turn of wheel 10, end of the channel 30 shown opposite to the ground). The piston 91 oscillates between the positions indicated by the distances D1 and D2, which draws air from the main cavity 20.

Figures 7a and 7b show an alternative implementation of the lid 33 of Figures 2 to 4 (detail Vil of Figure 2). The channel 30 ends with a well 34, made of rubber for example, which encloses a chimney 35 pierced on its side face. When the pressure P1 (FIG. 7a) prevailing in the tube 31 (outside the well 34) is equal to the atmospheric pressure inside the well 34, the latter elastically encloses the chimney 35. vacuum is created in the channel 30, then the pressure P2 (Figure 7b) in the tube 31 (outside the well 34) is less than the atmospheric pressure inside the well 34, the latter releases the side face of the chimney 35 as shown, which makes it possible to transmit the vacuum towards the tread of the tire 12.

According to this implementation, there is no detachable cap, but the channel 30 is still protected impurities by the well 34 as the channel 30 is not evacuated.

It will be understood that various modifications and / or improvements obvious to those skilled in the art can be made to the various embodiments of the invention described in the present description without departing from the scope of the invention.

Claims (15)

A vehicle floor-connecting device, comprising: - a wheel (10) of the vehicle, - a vacuum source, - a plurality of channels (30) arranged between the vacuum source and a tread of the vehicle. wheel (10), means for opening and closing the channels (30), arranged between the vacuum source and the tread to open or close an air passage in each channel (30), characterized in that the ground engaging device further comprises an angular position detecting unit (60) arranged to determine an angular position of the wheel (10), so as to control the opening and closing means for opening or closing independently each air passage according to the angular position of each channel (30). 2. A ground connection device according to the preceding claim, wherein the vacuum source comprises at least one main cavity (20) under vacuum arranged in the wheel (10), forming a vacuum reserve. Ground-connecting device according to claim 2, wherein the wheel (10) comprises an intermediate cavity (21) connected to each of the channels (30), and separated from the main cavity (20) under vacuum by a mechanism of porting (70). Ground-connecting device according to one of the preceding claims, wherein the wheel (10) comprises a tire (12), in which each channel (30) is formed at least in part by a tube (31), the device comprising an internal carcass (53) arranged in the tire (12) and traversed by the tube (31) of at least one channel (30). 5. A ground connection device according to the preceding claim, comprising a positioning structure (50) of the inner carcass (53) arranged to position the inner carcass (53) relative to the tire (12) and / or to a rim ( 11) receiving the tire (12). 6. ground binding device according to one of the preceding claims, wherein each of the plurality of channels (30) is provided with a valve arranged at the tread and having a state at least partially closed before activation opening and closing means. 7. A ground connection device according to the preceding claim, wherein the valve is a cap disposed in each of the plurality of channels (30) at the tread. The ground connection device according to claim 6, wherein the valve is formed by a well (34) enclosing a chimney (35), wherein an inner surface of the well (34) is exposed to an external pressure, and a outer surface of the well (34) is exposed to a pressure in the channel (30), and wherein the well (34) is arranged to release an opening of the stack (35) if the internal pressure reaches a lower pressure of 0.5 bar (a) at the outside pressure. 9. A ground connection device according to one of the preceding claims, wherein each of the plurality of channels (30) is normally closed before an activation of the opening and closing means, activation decided after detection of a situation of 'emergency. 10. A ground connection device according to one of the preceding claims, wherein the opening and closing means are arranged to control an opening of the air passage of each channel (30) whose end is close of the ground, and / or to maintain an opening of the air passage of each channel (30) whose end is close to the ground. 11. A ground connection device according to the preceding claim, wherein an end of a channel (30) is judged near the ground if it is in an angular sector of the wheel (10) centered on a straight line passing through the center of the wheel (10) and a point of contact between the wheel (10) and the ground, and a range of ± 10 ° around this line. 12. A ground connection device according to one of the preceding claims, comprising a passive pumping unit arranged between a rigid portion of the wheel (10) and a deformable portion of the wheel (10), to create or maintain a level of empty in the vacuum source when driving the vehicle 13. A ground connection device according to the preceding claim, wherein the passive pumping unit is formed by at least one piston (91) connected to the tread, and arranged to slide in a liner bound to a rim (11). ), so as to form a vacuum chamber comprising at least one non-return valve, for creating or maintaining a vacuum level in the vacuum source during a rolling of the vehicle. 14. A ground connection device according to the preceding claim, wherein the piston (91) is embedded on a channel (30). 15. Vehicle comprising at least one ground connection device according to one of the preceding claims.