Vehicle tanks

Abstract

Disclosed is a tank (2) for a vehicle (1), configured to store an energetic fluid, the tank being characterized in that the tank forms a structural part of the vehicle.

Description

[Technical Field]

[0001] The present invention relates to a tank for a vehicle, which tank is intended to store an energetic fluid, in particular hydrogen. The invention also relates to a chassis for a vehicle equipped with such a tank. The invention further relates to a vehicle, in particular an automobile, equipped with such a tank and / or such a chassis. [Background technology]

[0002] To ensure low-pollution vehicle operation, vehicles equipped with fuel cells powered by hydrogen are known. Therefore, these vehicles are equipped with tanks in which hydrogen is stored and then consumed by the fuel cell. The hydrogen pressure in these tanks can be very high, for example, around 700 bar. Therefore, the tanks must be particularly resistant to the mechanical stresses exerted by the pressurized hydrogen. Furthermore, hydrogen is a highly flammable gas that poses a fire risk in the event of a leak. Therefore, hydrogen tanks must also be impact-resistant to ensure passenger safety in the event of a vehicle accident.

[0003] Tanks known from the prior art are generally in the form of one or more cylinders mounted on the vehicle and arranged, for example, under the seats of the vehicle. These tanks are very heavy and therefore increase the overall weight of the vehicle, which is contrary to the objective of providing a more economical vehicle in terms of energy. Furthermore, the tanks are also very bulky and, when incorporated into the vehicle, reduce the volume available for passengers or for storing goods. Finally, these tanks are also complicated to fix in a secure and stable manner within the vehicle. Summary of the Invention

[0004] SUMMARY OF THE INVENTION The object of the present invention is to provide a tank for a vehicle which overcomes the above-mentioned drawbacks and which is an improvement over the known tanks of the prior art.

[0005] More particularly, a first object of the present invention is to provide a vehicle equipped with a tank intended to store an energetic fluid such as hydrogen, which is relatively light, easy to assemble and capable of holding a relatively large volume for passengers or for storage.

[0006] The present invention relates to a tank for a vehicle, the tank being adapted to store an energetic fluid and forming a structural element of the vehicle.

[0007] The tank may include at least a first pair of opposing walls connected to one another by a first assembly of hollow connecting elements extending through the tank and parallel to a first axis.

[0008] The tank may comprise at least a second pair of opposing walls connected to one another by a second assembly of hollow connecting elements extending through the tank parallel to a second axis, the second axis forming an angle not equal to zero with the first axis, in particular the tank comprises at least a third pair of opposing walls connected to one another by a third assembly of hollow connecting elements extending through the tank parallel to a third axis, the third axis forming an angle not equal to zero with the first axis and the third axis forming an angle not equal to zero with the second axis.

[0009] The tank may include at least one fastening interface disposed at one end of the at least one connecting element.

[0010] The at least one fixation interface may include a threaded insert configured to cooperate with a fixation screw and / or an insert configured to cooperate with a clip.

[0011] The tank may have a rigid structure made of composite materials.

[0012] The tank may be configured to store energetic fluids, in particular hydrogen, at pressures of 700 bar or more.

[0013] The invention also relates to a chassis for a motor vehicle comprising a tank such as defined above.

[0014] The chassis may include two side bars extending in the longitudinal direction, and the tank may be fixed to each of the two side bars at a longitudinal continuation of the two side bars.

[0015] The invention also relates to a vehicle, in particular a motor vehicle, comprising a tank as defined above and / or a chassis as defined above.

[0016] These objects, features and advantages of the present invention will be explained in detail in the following description of particular embodiments, given by way of non-limiting example with reference to the accompanying drawings. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a schematic side view of a vehicle according to an embodiment of the present invention; [Figure 2] FIG. 2 is a partial perspective plan view of the chassis of the vehicle. [Figure 3] 1 is a side view of a tank of a vehicle, with a fitting fastened to the top wall of the tank. [Figure 4] FIG. 4 is a plan view of the tank of FIG. 3. [Figure 5] FIG. 2 is a partial perspective bottom view of the chassis of the vehicle. [Figure 6] 1 is a perspective bottom view of the tank, the tank being provided with a protective casing. [Figure 7] FIG. 1 is a vertical view of a longitudinal section of the tank. [Figure 8A] FIG. 1 is a partial perspective view of an embodiment of a tank for a vehicle. [Figure 8B] FIG. 8B is a perspective view of the tank of FIG. 8A. [Figure 9] FIG. 2 is a cross-sectional view of a fastening interface of the tank according to the first embodiment. [Figure 10] FIG. 10 is a cross-sectional view of a fastening interface of a tank according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] FIG. 1 schematically illustrates an automobile 1 according to an embodiment of the present invention. The vehicle 1 may be, for example, a passenger car or a utility vehicle. Alternatively, the vehicle 1 may be a truck, a bus, a lifting machine, an agricultural machine, or any other type of land vehicle. The present invention may be particularly suitable for aircraft or boats. In this document, axis X denotes the longitudinal axis of the vehicle 1. When moving forward in a straight line, the vehicle 1 moves from rear to front in a direction parallel to its longitudinal axis. Axis X points from front to rear of the vehicle, i.e., in the direction of reverse travel. Axis Y denotes the transverse axis of the vehicle. Axis Y points from left to right, with left and right defined according to the perspective of the driver of the vehicle 1. Axis Z denotes an axis perpendicular to axes X and Y. The vehicle 1 can be considered to be placed on a horizontal ground surface. Axis Z is a vertical axis pointing from bottom to top. Axes X, Y, and Z form a Cartesian reference system. This frame of reference defined relative to vehicle 1 can be used to describe tank 2 on vehicle 1, even though the tank is intended to be integrated into the vehicle in a particular orientation and therefore can be considered to be outside the vehicle.

[0019] The vehicle 1 comprises a tank 2 according to an embodiment of the present invention. The tank 2 is intended to contain an energetic fluid that can be converted into an electric force capable of moving the vehicle, i.e. a fluid that forms an energy reserve. The tank 2 is therefore a part of the vehicle 1 that gives it a certain autonomy. The tank comprises in particular an inlet opening that makes it possible to fill it with energetic fluid and an outlet opening for supplying and then consuming the energetic fluid contained in the tank.

[0020] According to a preferred embodiment, the tank 2 is intended to store hydrogen, or more specifically dihydrogen. The vehicle 1 comprises a fuel cell 3 capable of converting hydrogen into electric current, and an electric motor 4 that is powered by the current output from the fuel cell 3. The vehicle 1 can also comprise an electrochemical battery 5, for example of the lithium-ion type. The electrochemical battery 5 can be charged by the current output from the fuel cell 3 and / or by connection to the electricity grid. The electric motor 4 can also be powered by the current output from the electrochemical battery 5. The tank 2 associated with the fuel cell 3 can therefore serve as a way to extend the autonomy of the vehicle when the electrochemical battery 5 is discharged.

[0021] As a variant, the vehicle 1 can be constructed differently. The vehicle 1 can be devoid of electrochemical batteries so that the tank 2 is the only energy source of the vehicle 1. According to another variant, the vehicle can be equipped with an internal combustion engine powered by hydrogen instead of a fuel cell. According to other variants, the tank 2 can be configured to store other types of energy gas, for example liquefied petroleum gas or natural gas. The tank may also be intended to store liquid fuels such as gasoline, diesel or ethanol.

[0022] The tank 2, which may be called a "storage device", is intended to store a pressurized energetic fluid, i.e., at a pressure strictly higher than atmospheric pressure. In this example, the tank 2 is intended to store an energetic fluid, in particular hydrogen, at a pressure of 700 bar or more. In variants, the tank 2 may be intended to store an energetic fluid at a different pressure, for example 300 bar or more, 500 bar or more, 1000 bar or more, or any other value. The tank 2 therefore comprises a robust structure 6 capable of withstanding the forces exerted by the pressurized fluid contained therein, i.e., outward forces acting from within the tank 2 and trying to rupture it.

[0023] Furthermore, the tank may have a capacity of more than 50 liters, preferably more than 100 liters, or even more than 150 liters. A 100 liter tank can store about 4 kg of hydrogen at 700 bar, which gives the car an autonomy of around 300 km.

[0024] The tank structure 6 is also able to withstand large impacts, in particular those that occur during an accident of the vehicle 1, without the energetic fluid leaking out. Data on accident rates and / or simulations and / or crash tests can determine the size of the structure 6, in particular the required wall thickness, so that even in the most severe accidents no leakage of the energetic fluid occurs.

[0025] According to the invention, the tank 2, which has the necessary high resistance to withstand the high pressure of the energetic fluid contained therein and to ensure the safety of the passengers of the vehicle 1 in the event of an accident, is advantageously used to form a structural element of the vehicle. The term "structural element" denotes an element of the vehicle that contributes to the overall rigidity of the vehicle. In other words, the tank 2 forms part of the body of the vehicle, i.e., part of the vehicle's framework. In particular, the tank 2 forms part of the vehicle's chassis, i.e., the part of the vehicle that can support the weight exerted by other vehicle equipment, such as the weight exerted by at least part of the vehicle's body. Furthermore, the tank not only supports the weight of certain equipment, but also provides a support to which these equipment can be attached.

[0026] In particular, the body of the vehicle 1 would not have sufficient rigidity without the tank 2. That is, the body of the vehicle 1 without the tank 2 would easily deform, especially due to the weight of the equipment mounted on the vehicle alone, or if the vehicle 1 were to crash, even at very low speeds. The tank 2 therefore constitutes an element of the body of the vehicle 1 that is essential for the rigidity and robustness of the vehicle 1. Therefore, by incorporating the tank 2 into the body, the amount of material used to manufacture the vehicle can be significantly reduced. As a result of the present invention, it is possible to reduce or even eliminate certain metal elements that were previously used to construct the body of the vehicle, especially the chassis.

[0027] The present invention is therefore particularly original in that the tank 2, which is conventionally supported on the vehicle body, becomes a component of the vehicle body. Furthermore, the present invention contradicts the conventional wisdom that tanks should be heavily protected as a result of the flammable or explosive nature of the energetic fluid contained therein. According to this conventional wisdom, the tank, under normal conditions of use, does not need to withstand any constraints other than those imposed by the energetic fluid contained therein.

[0028] According to the present invention, the tank can withstand loads of at least 100 kilograms, or even several hundred kilograms. These loads can be static loads, such as those imposed by the weight of the vehicle body and / or the weight of vehicle equipment such as seats and / or the weight of vehicle passengers. These loads can also be dynamic loads, such as those that appear in certain situations, such as during a vehicle collision. These various static or dynamic loads can impose compressive or shear forces on the tank. These forces are therefore directed in a different direction than the outward force exerted by the pressurized energetic fluid within the tank. Advantageously, the tank's resistance required to withstand the pressure exerted by the energetic fluid contained therein can also be used to withstand loads applied in various directions.

[0029] Vehicle equipment that can be supported by and fixed to the tank 2 includes, in particular: - equipment intended to be placed in the passenger compartment of a vehicle, in particular a seat on which the passengers of the vehicle can sit; and / or - Safety devices such as seat belts - Bodywork elements, and / or - shock absorbers, and / or - Wheelset, and / or - Protective casing

[0030] More generally, the tank 2 can serve to hold any component or equipment mounted on the vehicle. In particular, the tank can support any equipment other than the energy fluid storage or distribution system. The tank can also be used to connect several vehicle body elements to each other. Thus, it is conceivable that electrochemical batteries intended to supply the vehicle's power unit and / or the power unit and / or transmission means between the power unit and the drive wheels and / or wheel motors and / or suspension means are supported and fixed to the tank 2.

[0031] Referring to FIG. 2, the tank 2 may have a generally parallelepiped shape. The tank 2 may therefore have three pairs of opposing walls. A first pair of opposing walls is constituted by a front wall 7A and a rear wall 7B. The walls 7A and 7B extend substantially parallel to the axes Y and Z. A second pair of opposing walls is constituted by a left wall 8A and a right wall 8B. The walls 8A and 8B extend substantially parallel to the axes X and Z. A third pair of opposing walls is constituted by an upper wall 9A and a lower wall 9B. The walls 9A and 9B extend substantially parallel to the axes X and Y. Alternatively, any other shape of the tank may be envisaged.

[0032] The tank 2 can be located at the rear of the vehicle. In particular, the tank can form the rear portion of the vehicle chassis 10, i.e., the rear portion of the vehicle's undercarriage. The chassis 10 can include two side bars 11A, 11B extending parallel to the axis X on both sides of the vehicle. These two side bars 11A, 11B can only extend rearward to a position immediately in front of the vehicle's rear wheel arches, i.e., the rear ends of the side bars 11A, 11B are located in front of the vehicle's rear wheels. Therefore, the side bars 11A, 11B can be shorter than those of conventional automobiles. The tank 2 is directly fixed to each of the two side bars. Therefore, the tank 2 functions as a cross member of the vehicle by connecting the two side bars 11A, 11B to each other. Therefore, the two side bars can be rigidly fixed in position relative to each other by the tank 2. Therefore, the use of the tank 2 can save one or more cross members of the chassis 10. In any case, the vehicle 1 does not have any structural cross members connecting the two side bars above or below the tank 2. The vehicle also does not have any structural cross members behind or immediately in front of the tank 2.

[0033] The tank 2 extends toward the rear of the vehicle 1 on the longitudinal extension of the two side bars, i.e., the rear end of the tank 2, particularly the rear wall 7B, is located rearward of the rear ends of the side bars 11A and 11B. The distance D1 along the longitudinal axis between the rear ends of the side bars 11A and 11B and the rear edge of the tank 2 can preferably be 20 cm or more, 40 cm or more, or 60 cm or more. Thus, the tank 2 can extend below the trunk of the vehicle or into the area of ​​the rear fender of the vehicle. The tank can therefore be intended to support the load exerted by a set of objects stored in the trunk of the vehicle.

[0034] To ensure a good connection between the side bars 11A, 11B and the tank 2, a longitudinal cover is preferably provided between these components, i.e., the front edge of the tank is preferably located forward of the rear ends of the side bars 11A, 11B. Thus, a hinge effect at the interface between the side bars and the tank is avoided under the influence of vertical loads or longitudinal impacts. The distance D2 along the longitudinal axis between the rear ends of the side bars 11A, 11B and the front edge of the tank 2 is preferably at least 10 cm, at least 20 cm, or at least 40 cm. Preferably, the side bars 11A, 11B do not extend more than halfway along the longitudinal axis X of the tank 2. Each side bar 11A, 11B can be fixed to two side walls 8A, 8B of the tank, respectively.

[0035] The tank 2 can extend substantially under the base plate of the seats 12 of the vehicle 1, in particular the rear seats. The seats 12 (the base plates of which can be seen in Figures 6 and 7) can be in the form of individual seats or bench-type seats on which several people can sit side by side. The seats 12 can be supported by the tank and fixed to it. The seats 12 can also be foldable seats, with the support for the pivot of the seat back fixed to the tank 2.

[0036] The upper wall 9A may be provided with a recess 13 intended to receive the base plate of the seat 12 so that the seated passenger does not sit too high. This recess 13 is particularly clearly visible in Figure 3. Behind the recess 13, the upper wall 9A is provided with a horizontal surface 14. This horizontal surface 14 may be intended to form the floor of the trunk. The recess 13 extends lower along the vertical axis Z than the horizontal surface 14 behind the recess.

[0037] The recess 13 may have a profile parallel to the transverse axis Y. The recess 13 may have a bottom 15, in particular a horizontal bottom, surrounded at the front and rear by inclined walls 16. The recess 13 may have a length L1 along the longitudinal axis X that corresponds substantially to the length of the base plate of the seat 12 along the longitudinal axis X, or at least 50% of the length of the base plate of the seat 12. This length may be, for example, 10 cm or more, preferably 20 cm or more. The height difference H1 along the vertical axis Z between the bottom 15 of the recess 13 and the rear horizontal surface 14 of the recess may be, for example, 5 cm or more, preferably 10 cm or more. The height of the rear horizontal surface 14 of the recess 13 along the axis Z can be freely selected depending on the compromise between the storage space of the trunk and the capacity of the tank. The recess 13 may be located in the front half of the upper wall 9A, while the horizontal surface 14 may be located in the rear half of the upper wall 9A.

[0038] The chassis 10 does not include any further structural elements arranged between the tank 2 and the seat 12, thus saving weight and volume occupied by these components. Nevertheless, a protective or separating wall may be provided between the seat and the tank and / or between the trunk and the tank, particularly to improve appearance and comfort. However, this wall is not intended to support the seat or objects transported in the trunk, and as a result, its thickness may be reduced.

[0039] The tank 2 may also advantageously be provided with an anti-submarining device 17. Such a device forms a stop that prevents the base plate of the seat 12 from sliding forward in the event of an accident. The anti-submarining device 17 is formed by a protrusion extending forward and upward in front of the recess 13. The anti-submarining device 17 may have a contoured configuration along the axis Y and / or may extend across the entire width of the tank along the axis Y. As can be clearly seen in FIG. 7, the underside of the base plate of the seat 12 may have a configuration complementary to that of the anti-submarining device 17. Thus, the underside of the base plate of the seat 12 may have a contoured recess along the axis Y that engages with the protrusion of the anti-submarining device 17. In addition to improving passenger safety, incorporating the anti-submarining device 17 into the tank 2 allows for an increase in the tank's volume and, therefore, its storage capacity for energetic fluid.

[0040] The tank 2 also provides a support for fastening safety devices. The safety devices are intended to protect the vehicle's passengers in the event of an accident. In particular, the safety devices may include safety belts and / or devices conforming to the ISO 13216-1:1999 standard, more commonly known as the Isofix system. In particular, anchoring means 21 for safety belts and / or anchoring means 22 conforming to the ISO 13216-1:1999 standard may be fastened to the upper wall 9A of the tank. The anchoring means 21, 22 may be fastened, for example welded or screwed, to a plate which is itself screwed to the tank 2.

[0041] In this way, the tank 2 is intended to withstand the large tensile forces exerted by the anchoring means in the event of an accident. The anchoring means 21 can be connected to a safety belt clip-on device 23, also called a stalk. Such a clip-on device 23 protrudes between the base plate and the back of the seat 12 arranged above the tank and is intended to be activated by the passenger to lock or unlock the safety belt. Alternatively, the anchoring means 21 can also be connected to a safety belt return device and / or a safety belt retractor and / or a safety belt locking device. As can be clearly seen in Figures 3 and 4, the anchoring means 21 can be fixed to the bottom 15 of the recess 13.

[0042] The anchoring means 22 may comprise a curved bar 24, in particular made of metal and / or U-shaped, which is intended to cooperate with a fixing device integrated into a removable seat, for example a child car seat, in order to hold this securely. The curved bar 24 may also extend horizontally, perpendicular to the recess 13. In particular, the curved bar 24 may be welded to a plate 25 which is itself screwed to the tank in the region of the front edge of the horizontal surface 14.

[0043] Advantageously, one or more fixing hooks 26 for securing loads can also be fixed to the tank 2. The fixing hooks 26 may be fixed relative to a horizontal surface 14 arranged behind the recess 13. As can be seen in Figure 4, the fixing hooks 26 may, if applicable, be fixed, in particular welded, to the plate 25 to which the curved bar 24 is welded. Alternatively, the fixing hooks 26 may be fixed, in particular welded, to another plate.

[0044] The tank 2 also supports a rear portion of the vehicle body. This rear portion of the vehicle body may include, for example, legs extending substantially vertically to the vehicle roof and / or rear fins or rear quarter panels and / or rear portions of the vehicle's rear door surrounds and / or the vehicle's rear or trunk doors and such rear door surrounds. The portion of the vehicle body supported by the tank 2 may be fixed to the tank, particularly in the area of ​​the rear half of the tank's upper wall 9A. To this end, the chassis 10 includes a frame 28 fixed directly to the tank 2. The frame 28 may itself be fixed directly to a portion of the vehicle's body or may form the lower edge of the body. The frame 28 may be arranged around the tank's upper wall 9A. It may be generally U-shaped. The frame 28 may include, in particular, a first segment extending along the rear edge of the tank 2 and second and third segments extending along the tank's side edges. The frame 28 may be made of a metal material and / or in the form of a corner angle. The frame 28 may in particular comprise a wall 29 extending relative to the upper wall 9A of the tank. Said wall 29 may be fixed to the tank by fixing means such as fixing screws. The number and / or arrangement of the fixing screws may be freely selected to obtain the desired rigidity and retention. In particular, the fixing screws may be distributed at a regular pitch, for example at a pitch of between 5 cm and 30 cm, in particular at a pitch of between 10 cm and 20 cm.

[0045] The trunk base 27 is fixed directly to the tank 2 or to the tank 2 via a frame 28. The trunk base 27 comprises the rear wall of the trunk that extends transversely and vertically below the trunk door in the closed position. A means for locking the trunk door, such as a latch wire, can also be fixed to the trunk base 27.

[0046] The vehicle 1 further comprises an impact absorbing device 30 supported by and fixed to the tank 2. In particular, the impact absorbing device 30 is fixed only to the tank 2. The impact absorbing device 30 is therefore not fixed to the side bars or to the metal cross members of the vehicle.

[0047] The impact absorbing device 30 is intended to absorb all or part of the kinetic energy transferred to the vehicle 1 upon impact with the impact absorbing device 30. As such, the impact absorbing device 30 may be incorporated into a fender of the vehicle. The impact absorbing device 30 may also be covered by a trim part of the vehicle.

[0048] According to this embodiment, the impact absorbing device 30 is arranged to withstand longitudinal impacts to the rear of the vehicle, and is therefore incorporated into the rear fender of the vehicle. In a variant, the impact absorbing device 30 is arranged to withstand longitudinal impacts to the front of the vehicle, and can therefore be incorporated into the front fender.

[0049] When an impact occurs against the shock absorbing device 30, the force is automatically transmitted to the tank 2. Due to its high resistance and robustness, it can withstand this force without damage or deformation. The impact force is then transmitted to the side bars 11A, 11B, which extend further towards the front of the tank 2. The tank 2 therefore functions as an intermediate component between the shock absorbing device 30 and the side bars 11A, 11B. In other words, the shock absorbing device 30 is connected to the side bars via the tank 2.

[0050] The impact absorbing device 30 comprises an assembly of a rear impact cross member 31, a pillar 32 intended to deform upon impact, and a support 33 intended to be fixed directly to the tank 2. The rear impact cross member 31 is fixed to the tank via the pillar 32 and the support 33. The pillar can be said to have a "planned deformation", i.e. the pillar can be configured to deform in a predictable manner upon impact against the rear impact cross member 31 in order to optimize the amount of energy absorbed by the deformation and / or to effectively control the deformation mode of the impact absorbing device 30. To this end, the pillar may be provided with weak points such as openings or notches.

[0051] The rear impact cross-member 31 may extend at least approximately parallel to the transverse axis Y at the rear of the tank 2. A pillar may extend parallel to the longitudinal axis X between the rear impact cross-member 31 and the rear wall 7B of the tank. The pillar 32 thus comprises a first end fixed, for example welded, to the support 33 and a second end fixed, for example welded, to the rear impact cross-member 31. The pillar may have a square, rectangular or any other form of cross-section.

[0052] According to one variant, the pillars 32 can also extend obliquely to the longitudinal axis X. The axes along which the pillars extend can, for example, form an angle with the longitudinal axis X between 0° and 30°, or even between 0° and 45°.

[0053] According to one embodiment, the rear impact cross member 31 can be fixed to the support 33 by a single pillar 32. This single pillar is preferably located in the center of the impact absorbing device 30. The rear impact cross member 31 is preferably fixed to the support 33 by at least two pillars 32, or at least three pillars 32, or even at least four pillars 32. These pillars 32 may be distributed across the width of the tank 2 along the transverse axis Y. Figure 2 shows an impact absorbing device with two pillars 32, while Figures 3, 4, and 5 show an impact absorbing device with four pillars 32. There may be any number of pillars. Preferably, the pillars are spaced apart so that they do not interfere with each other when deformed under impact.

[0054] The tank 2 provides a wide rear wall 7b, which provides a large surface for fixing the impact absorbing device 30. It is therefore easier to increase the number of pillars supporting the rear impact cross-member 31, thereby improving the energy absorption capacity of the impact absorbing device 30. The invention therefore allows for significant benefits compared to vehicles with rear impact cross-members 31 fixed to the vehicle's side bars, since such vehicles have only two pillars facing each side bar, which reduces their energy absorption capacity.

[0055] According to one embodiment, instead of or in addition to the pillars 32, a honeycomb structure can be provided between the rear wall 7B of the tank and the rear impact cross member 31.

[0056] The design of the rear impact cross member 31 can be simplified since the cross member can be supported by a greater number of pillars and / or honeycomb structures. The rear impact cross member 31 may, for example, have a simple rectangular form parallel to the transverse axis Y, i.e., a non-curved shape. The cross section of the rear impact cross member 31 may, for example, be U-shaped. Nevertheless, cross members in the form of a circular arc about an axis parallel to the vertical axis Z are also possible.

[0057] The support 33 may comprise a main plate 34 extending parallel to the transverse axis Y and the vertical axis Z. This main plate 34 is fixed to the rear wall 7B of the tank, in particular by means of a set of fixing screws extending through holes in the plate. Since the main plate 34 is supported by the rear wall 7B, the main plate 34 may be relatively thin. For example, the main plate 34 may have a thickness of 2 mm or less. The main plate is not intended to further stiffen the tank. Its only role in the event of an impact is to distribute the pressure exerted by the pillars over a wider surface. The main plate is therefore not a cross-member of the chassis.

[0058] The support 33 may also comprise auxiliary plates 35 perpendicular to the main plate 34. According to the embodiment shown, the auxiliary plates 35 extend parallel to the longitudinal axis X and the vertical axis Z and are fixed, in particular by means of fixing screws, to the tank side walls 8A and 8B, respectively. The fixation of the shock absorbing device 30 by the transverse plates 35 in addition to the fixation by the main plate 34 improves the resistance of the shock absorbing device.

[0059] According to one variant, the support 33 can comprise only a single auxiliary plate. According to another variant, the support 33 can comprise an auxiliary plate extending parallel to the longitudinal axis X and the transverse axis Y and fixed to the upper wall 9A. The support 33 can also comprise an auxiliary plate extending parallel to the longitudinal axis X and the transverse axis Y and fixed to the lower wall 9B.

[0060] In the event of an impact at the rear of the vehicle, the pillars 32 deform and absorb the energy of the impact. In particular, the pillars 32 are compressed between the cross member 31 and the main plate 34, which abuts the rear wall of the tank. The shock wave is transmitted by the tank 2 to the side bars 11A, 11B. The tank has a non-deformable or substantially non-deformable structure 6 and therefore transmits all of the load it receives to the side bars 11A, 11B. In the case of a moderate impact, only the pillars deform. Repair work on the vehicle is particularly simple, as it is only necessary to unscrew the impact absorber 30 on the tank 2 and replace it with a new one.

[0061] FIG. 5 is a bottom view of the vehicle chassis 10. It can be seen that the tank 2 can comprise two cavities 40A, 40B intended to accommodate elements 41A, 41B of the wheelset of the vehicle 1. These cavities 40A, 40B open downwards, respectively towards the sides of the tank. These cavities can be delimited by an assembly of vertical and horizontal walls 42, 43, extending halfway up the tank. By arranging the cavities 40A, 40B in the tank 2, the bottom wall 9B of the tank can be closer to the ground, especially outside these cavities. The bottom wall 9B therefore comprises a horizontally extending region 45 (substantially H-shaped according to the embodiment shown in FIG. 5) lower than the elements 41A, 41B of the wheelset. This makes it possible to increase the tank's volume and lower the center of gravity of the vehicle, thereby improving stability.

[0062] Advantageously, the vehicle 1 does not have any carrier structure for supporting the tank 2 from below. As a result of its great resistance, the tank 2 may be exposed to impacts occurring under the underside of the vehicle, for example impacts caused by stones being kicked up or by crossing a pavement. Nevertheless, as will be described below, it is possible to fix a protective casing under the tank 2 to provide further protection.

[0063] Therefore, as shown in Figures 6 and 7, the vehicle advantageously includes a protective casing 44 fixed to the tank 2. The protective casing 44 extends horizontally below the tank 2. The protective casing 44 can be fixed directly to the tank 2 without any intermediate parts. The protective casing 44 has an upper surface facing the lower wall 9B of the tank and a lower wall exposed to protrusions occurring on the road. The lower wall 9B is therefore protected from impacts caused by kicked-up stones or when crossing a sidewalk.

[0064] Advantageously, the protective casing 44 closes off the cavities 40A, 40B from below. In other words, the cavities 40A, 40B are delimited from below by several parts of the protective casing 44. The protective casing 44 is thus able to protect the wheelset elements 41A, 41B.

[0065] The protective casing 44 is preferably a single block element, i.e. made in a single piece. It therefore offers better protection against splashes of water compared to a protective casing formed by several elements assembled together. The protective casing 44 may have a generally rectangular shape. It preferably extends under the entire lower wall of the tank 2. It therefore extends across the entire width of the vehicle undercarriage along the transverse axis Y, up to a position near the wheels connected to the elements 41A, 41B of the vehicle's wheelset.

[0066] The protective casing allows the vehicle to be offered with a flat bottom, which improves the aerodynamics of the vehicle and reduces the risk of foreign objects getting stuck to the underside of the protective casing relative to the vehicle.

[0067] The protective casing 44 may be made of plastic material, metal or any other material, and may contain several materials, particularly to improve the level of sound insulation.

[0068] According to one embodiment, the protective casing 44 may include a deflector 46 configured to create a ground effect by air circulation. The ground effect is an aerodynamic effect intended to press the vehicle against the ground, thus improving grip on the ground. The deflector 46 may include a surface slightly inclined relative to the longitudinal axis X. This inclined surface may extend rearward and upward at the rear of the protective casing 44. Alternatively or additionally, the protective casing 44, and in particular the deflector 46, may also include fins that protrude downward and extend in a plane parallel to the longitudinal axis X and the vertical axis Z. Such fins improve the lateral stability of the vehicle.

[0069] The protective casing 44 may be fixed only to the tank. Alternatively, the vehicle may be provided with a rear fender element located behind the protective casing 44. The protective casing 44 may be fixed to this rear fender element. To improve protection, an overlap may be provided between the rear fender element and the protective casing.

[0070] Advantageously, the vehicle 1 can also comprise an acoustic filtering element sandwiched between the protective casing 44 and the tank's lower wall 9B. The acoustic filtering element can improve the sound insulation of the passenger compartment, which is particularly advantageous when the vehicle is equipped with an electric drive, since such a drive is very quiet in operation. The acoustic filtering element may, for example, comprise a layer of felt and / or foam.

[0071] With reference to FIG. 5, it can also be seen that the electrochemical cell 5 extends in front of the tank 2 along the longitudinal axis X. In particular, the electrochemical cell 5 extends between the two side bars 11A, 11B and is fixed to the two side bars 11A, 11B. The electrochemical cell 5 has a lower wall oriented toward the ground. The vehicle may also be equipped with a second protective casing (not shown) configured to protect the lower wall of the electrochemical cell. The protective casing 44 can be fixed to the second protective casing. For better protection, an overlap can also be provided between the protective casing 44 and the second protective casing.

[0072] The structure 6 of the tank 2 is advantageously made of composite materials. Such materials are lighter than steel and even lighter than any other metal with comparable resistance. Furthermore, the methods for manufacturing components from composite materials allow the production of structures 6 with a wide variety of geometric shapes. Thus, structural shapes 6 that are more complex than those obtained from metals can be envisaged, in order to fully utilize the volume available in the vehicle and thus increase the capacity of the tank. When the tank is intended to store pressurized gases rather than liquids, more complex shapes of the tank are particularly recommended, since, unlike liquids, there is no risk of the gases becoming trapped in the tank.

[0073] Composite materials can include draped or preformed structures and / or woven and resin-impregnated materials. Composite materials can be based on reinforcing elements and a matrix. The reinforcing elements can include carbon fiber or glass fiber, which are lightweight materials, or Kevlar®, which has greater resistance to impact. The matrix can be an organic matrix, such as an epoxy resin, a phenolic resin, or a modified polyester. The matrix can also be a metal matrix.

[0074] 8A and 8B are perspective views of structure 6 of an embodiment of tank 2. Walls 7A and 7B are connected to each other by a first assembly of connecting elements 51 extending parallel to axis X. Similarly, walls 8A and 8B are connected to each other by a second assembly of connecting elements 52 extending parallel to axis Y, and walls 9A and 9B are connected to each other by a third assembly of connecting elements 53 extending parallel to axis Z.

[0075] According to one variant, the tank 2 may comprise only a single assembly of connecting elements or only two assemblies of connecting elements out of the three assemblies of connecting elements 51, 52, 53. In a variant, all or some of the assemblies of connecting elements 51, 52, 53 may extend in directions different from the axes X, Y and Z, as long as the axis along which each assembly of connecting elements extends forms a non-zero angle with the axis along which the other assemblies of connecting elements extend. Advantageously, the three axes along which the three assemblies of connecting elements 51, 52 and 53 extend are perpendicular to one another so as to stiffen the tank in an optimal manner.

[0076] The connecting elements 51, 52, 53 extend through the tank 2 on both sides between the two opposing walls. They act as tie rods that strengthen the resistance of the tank and are subjected to tensile forces when the energetic fluid contained in the tank exerts pressure on the walls 7A, 7B, 8A, 8B, 9A and 9B. The connecting elements 51, 52, 53 are arranged inside the outer shell of the tank 2 and not around this outer shell.

[0077] Each connecting element is separated from the other connecting elements, i.e., the connecting elements are not in contact with each other and preferably do not come into contact with each other within the tank 2. Therefore, the tank 2 is not partitioned and the energy fluid can easily circulate within the tank 2.

[0078] The connecting elements 51, 52, 53 are hollow. In particular, the connecting elements, which may also be called "reinforcing wells," may be tubes if they have a circular cross section. However, the cross section of the connecting elements is not necessarily circular. For example, the cross section of the connecting elements may also be square, rectangular, polygonal, or oval.

[0079] 9 shows the connecting element 51 in more detail, the other connecting elements being constructed in a similar manner. Each connecting element 51, 52, 53 has a tubular form with an outer surface 54 and an inner surface 55. The outer surface 54 faces the interior of the tank and is therefore intended to be in contact with the energetic fluid, while the inner surface 55 communicates with the exterior of the tank and is therefore intended to be in contact with the ambient air.

[0080] The connecting elements 51, 52, 53 can be made of composite material or metal, or they can simultaneously comprise composite and metal, in particular metal tubes arranged in a structure made of composite material.

[0081] The inner surface 55 may comprise a material different from that forming the structure 6 of the tank. The inner surface 55 may in particular comprise a metal tube extending over the entire length of the connecting elements 51, 52, 53 or only in the region of the ends of the connecting elements 51, 52, 53. The metal tube may, if applicable, be annealed over its outer periphery to ensure good retention within the structure 6.

[0082] Each connecting element 51, 52, 53 has two opposite ends in the area of ​​the two opposite walls it connects. As a result of the connecting elements being hollow, the tank has, for each connecting element, an opening 56 that passes completely through the tank. These openings 56 do not communicate with the energy fluid storage volume. Therefore, these openings 56 do not serve for the supply of energy fluid, in particular for the supply of pressurized hydrogen to the fuel cell 3.

[0083] On the other hand, opening 56 can be used for the introduction of electrical wires and / or hydraulic conduits, thus saving space outside the tank for the introduction of these electrical wires and / or hydraulic conduits, while providing a way to fix these wires and / or hydraulic conduits in place.

[0084] The openings 56 can also be used to allow liquids to be drained from the vehicle or to generate ventilation elements intended to cool or heat the passenger compartment.

[0085] As will be explained below, the openings 56 can be advantageously used to fasten various vehicle accessories, in particular the openings 56 being used to fasten the seat 12, the anchoring means 21, 22 of the safety device, the body frame 28, the shock absorbing device 30, the wheel set elements 41A, 41B and the protective casing 44, as mentioned above.

[0086] For this purpose, the tank 2 comprises a group of fastening interfaces 57, each of which is located at one end of at least one connecting element 51, 52, 53, in particular at the end of the opening 56. As shown in FIG. 9, all or some of the fastening interfaces 57 can comprise inserts intended to cooperate with fastening screws 58, for example, M8 or M10 type fastening screws. The inserts can be formed as metal tubes fitted into the inner surface 55 of the connecting element, or they can be additional elements, such as plastic pins, pressed into the inner surface 55 of the connecting element. The inserts can have a length of, for example, between 20 mm and 60 mm. The inserts can be threaded or unthreaded. Thus, the inserts provide a fastening means that extends deep into the tank's volume. Such fastening means are particularly robust and allow for the fastening of large loads.

[0087] As shown in FIG. 10 , all or part of the fastening interface 57 may comprise an insert intended to cooperate with a clip 59. The clip 59 may comprise radial fins that can interfere with a tubular insert and be forcefully engaged with the insert. Alternatively, the clip 59 may have any other form. For example, it may be intended to be forcefully engaged and unscrewed for removal. Furthermore, adhesive or mastic may be applied to the opening 56 to improve the resistance of the fastening screw 58 or clip 59. The use of clips 59 may be preferable to the use of fastening screws, which have a moderate mass and are intended for fastening equipment other than the safety article, such as the protective casing 44.

[0088] Each fastening interface 57 allows a piece of vehicle equipment to be fastened to the tank wall. The fastening interface 57 can be arranged at the end of the opening 56 located on the side of the wall to which the equipment is fastened. Alternatively, the fastening interface 57 can also be arranged at the end of the opening 56 located on the opposite side of the wall to which the equipment is fastened. In this case, a shaft or cable connecting the fastening interface 57 to the equipment can extend into the opening 56. Such an arrangement makes it possible to provide a fastening interface in the area of ​​the lower wall 9B, for example, for fastening equipment to the upper wall 9A, which facilitates vehicle assembly or maintenance work.

[0089] Preferably, one or more fixing interfaces arranged on the side walls 8A and 8B are used to fix the side bars 11A and 11B, respectively. One or more fixing interfaces arranged on the upper wall 9A are used to fix the seat 12 and / or the anchoring means 21, 22 and / or the body frame 28. One or more fixing interfaces arranged on the rear wall 7B are used to fix the impact absorbing device 30. One or more fixing interfaces arranged on the lower wall 9B are used to fix the protective casing 44.

[0090] Such a fixing interface 57 can advantageously be provided at the end of each opening 56 of the tank. Each connection element 51, 52, 53 can thus support two fixing interfaces 57 arranged on two opposite faces of the tank. The tank can therefore be provided with a large number of fixing interfaces 57 making it possible to fix different fittings in different positions.

[0091] The same equipment can also be fixed to the tank 2 using two or more fixing interfaces to ensure proper fixing protection. Also, the same equipment can be easily fixed to different positions on the tank without the need for modifications.

[0092] The multiple fastening interfaces also allow for several possible ways of fastening equipment, so that the same tank 2 can be easily reused on different models of vehicle.

[0093] Openings 56 that are not intended for fastening vehicle equipment can be closed with a closing means to prevent the accumulation of mud, sand, earth, stones, or any other particles. In particular, unused openings 56 can be closed with individual plugs, or with a film that surrounds the entire tank, or with any other protective device. Unused openings 56 can be used, if applicable, during the life of the vehicle, for example, to fasten new equipment or new accessories. For maintenance work, it is conceivable that an equipment item, such as the shock absorber 30, is disassembled and replaced with a new equipment item, which is then fastened using the fastening interface that remained unused until that point.

[0094] Advantageously, the connecting elements 51, 52, 53 are distributed according to a regular pitch, for example, between 5 cm and 30 cm, in particular between 10 cm and 20 cm. As a result, the fastening interfaces 57 are distributed according to a regular pitch across the tank wall. The fastening interfaces 57 are therefore arranged according to a grid pattern on the surface of the tank 2. This further facilitates the reuse of the same tank and the same accessories for different vehicle models, since the same accessories can be fixed in several locations on the tank without the need for adaptation pieces. The tank thus forms a modular structure, similar to Lego blocks, to which several accessories can be fixed. The present invention therefore allows for a great degree of design freedom for the vehicle, while achieving economies of scale.

[0095] To manufacture the vehicle 1, it is possible to first manufacture the chassis, in particular by assembling the tank 2 to the side bars 11A, 11B. The various vehicle accessories can then be fastened to the tank 2. In particular, as described above, the seat 12, the anchoring means 21, 22 of the safety devices, the body frame 28, the shock absorber 30, the wheel set elements 41A, 41B, and the protective casing 44 are fastened to the tank 2 by means of fastening interfaces 57. Therefore, the assembly of the tank is carried out before the fastening of these various accessories in the vehicle manufacturing process. The fastening of these various accessories can be carried out simply by tightening the fastening screws 58 or engaging the clips 59. This also facilitates maintenance work that requires the disassembly of these accessories.

[0096] Finally, the invention has the advantageous advantage that vehicles equipped with a tank for the energetic fluid are lighter, since part of the metal chassis that the vehicle previously had is saved. Also, since the tank occupies part of the volume previously occupied by the chassis, the vehicle offers more space for passengers or for storage. Alternatively, this available volume can be used to increase the size of the tank, thus providing a vehicle with greater autonomy. Finally, the tank provides a particularly practical support for fastening a wide variety of equipment on board the vehicle.

Claims

1. A tank (2) for a vehicle (1), adapted to store an energetic fluid, characterized in that the tank (2) forms a structural element of said vehicle.

2. 2. The tank (2) according to claim 1, characterized in that it comprises at least a first pair of opposing walls (7A, 7B) connected to each other by a first assembly (51) of hollow connecting elements extending through the tank and parallel to a first axis (X).

3. at least a second pair of opposing walls (8A, 8B) connected to one another by a second assembly (52) of hollow connecting elements extending through the tank and parallel to a second axis (Y), said second axis forming an angle with said first axis not equal to zero; 3. The tank (2) according to claim 2, characterized in that it comprises at least a third pair of opposing walls (9A, 9B) connected to one another by a third assembly (53) of hollow connecting elements extending through the tank and parallel to a third axis (Z), said third axis forming an angle not equal to zero with the first axis and said third axis forming an angle not equal to zero with the second axis.

4. 4. Tank (2) according to claim 2 or 3, characterized in that it comprises at least one fastening interface (57) arranged at one end of at least one connecting element (51, 52, 53).

5. 5. The tank (2) according to claim 4, characterized in that the at least one fastening interface (57) comprises a threaded insert configured to cooperate with a fastening screw (58) and / or an insert configured to cooperate with a clip (59).

6. Tank (2) according to any one of claims 1 to 5, characterized in that it comprises a rigid structure (6) made of composite material.

7. 7. A tank (2) according to any one of claims 1 to 6, characterized in that it is adapted to store an energetic fluid, in particular hydrogen, at a pressure of 700 bar or more.

8. A chassis (10) for a motor vehicle, characterized in that it comprises a tank (2) according to any one of claims 1 to 7.

9. 9. The chassis (10) according to claim 8, characterized in that it comprises two side bars (11A, 11B) extending in the longitudinal direction, and the tank (2) is fixed to each of the two side bars at their longitudinal continuations.

10. A vehicle (1), in particular a motor vehicle, characterized in that it comprises a tank (2) according to any one of claims 1 to 7 and / or a chassis according to claim 8 or 9.

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