FR3078048A1 - BATTERY PROTECTION DEVICE IN CASE OF LATERAL SHOCK AND VEHICLE EQUIPPED WITH SUCH A DEVICE - Google Patents

Abstract

The invention relates to a hybrid or electric motor vehicle whose structure comprises, at each of its lateral sides, a spar (1) arranged parallel to a subfloor stretcher (3); the vehicle further comprising a propulsion battery and at least one battery protection device (17); the vehicle being remarkable in that a battery protection device (17) is disposed between said spar (1) and said subfloor stretcher (3) and in that said protection device (17) comprises at least one element arcuate (19) force distribution. The invention also relates to such a protection device.

Description

BATTERY PROTECTION DEVICE IN THE EVENT OF LATERAL SHOCK AND

VEHICLE EQUIPPED WITH SUCH A DEVICE

The present invention relates to the automotive field and applies more particularly to a motor vehicle of the hybrid vehicle or electric vehicle type. The invention relates to the field of passive vehicle safety equipment. In particular, the invention is in the field of the protection of vehicles against side impacts. The invention relates to a battery protection device and to a vehicle equipped with such a device.

Electric type motor vehicles include only an electric motor. Hybrid vehicles include an electric motor in addition to a heat engine. The two motors operate simultaneously or alternately so as to reduce the total power consumed by the vehicle. The propulsion battery of the electric motor is generally of rectangular shape and is housed under the rear passenger seats.

The propulsion battery is exposed during a side impact of the "post" type, in which the spar will deform and strike the battery on one of its side faces. There is a risk of electric shock or chemical burns to passengers.

The management of "pole" type shocks at the batteries is currently done by deformation of the structure (shock absorption) and by transmission of forces in the structural sleepers when the impact is made at their level. It is also possible to have a protective frame or a shell around the battery to further improve the safety benefits. However, there is a constant need to go further and further improve vehicle safety.

For example, the document FR2710893 proposes a motor vehicle chassis comprising a non-deformable base frame and two front and rear absorption zones associated with said frame. The frame and the absorption zones have a honeycomb structure. This solution is interesting, but requires significant investments since it involves modifying the chassis of the vehicles. It would be interesting to find a solution that is adaptable to existing vehicles and easy to implement.

The aim of the invention is to provide a solution to at least one of the drawbacks of the prior art. In particular, the invention aims to provide a protection device that can be used on existing vehicles without changing their design. The invention also aims to provide vehicles showing enhanced safety by the presence of such devices.

To this end, and according to a first aspect, the invention relates to a hybrid or electric type motor vehicle, the structure of which comprises, at each of its lateral sides, a spar arranged parallel to a sub-floor stretcher; the vehicle further comprising a propulsion battery and at least one battery protection device; the vehicle being remarkable in that a battery protection device is disposed between said spar and said sub-floor stretcher and in that said protection device comprises at least one arcuate force distribution element.

As will have been understood on reading the definition which has just been given thereof, the invention consists in making use of existing spaces in vehicles which were hitherto unused, in order to place there devices for protecting the battery of propulsion. The protective devices in question are designed to distribute the forces received locally, following a "pole" type impact, by the presence of one or more arched elements. Each arched element has an arch comprising a top and two feet. In a preferred implementation of the invention, the feet of the arched elements are placed in abutment on a sub-floor stretcher so that the top is arranged facing the spar. The force resulting from an impact located at the level of the top of an arched element will be transmitted by its legs to its feet and therefore distributed between the two feet.

Advantageously, the forces coming from the feet of the arched element are then transmitted to structural crosspieces arranged under the propulsion battery, so as to create a force path which bypasses said battery. Also, according to a preferred embodiment of the invention, the vehicle comprising two sub-floor stretchers and at least two structural cross members extending between said sub-floor stretchers in the transverse direction of the vehicle, the vehicle is remarkable in that 'at least one arcuate force distribution element comprises two feet and in that it is arranged so that said feet are placed in abutment on the sub-floor stretcher in alignment with said structural sleepers. The structural crosspieces and the feet of the arched element or elements are aligned in the transverse direction of the vehicle. The feet of the arched element (s) are arranged to be placed as an extension of said structural crosspieces.

According to one embodiment of the invention, the protection device comprises a plurality of arcuate elements succeeding one another in the longitudinal direction of the vehicle. The different arched elements may have come in one piece and form a single assembly showing a plurality of successive legs and arches. Preferably, to facilitate their installation and their manipulation, the arched elements each comprise a single arch and two feet. Preferably, the vehicle comprising two sub-floor stretchers and at least three structural cross members extending between the sub-floor stretchers in the transverse direction of the vehicle, the vehicle is remarkable in that it comprises at least two arcuate elements for distributing 'efforts arranged to succeed in the longitudinal direction of the vehicle. Preferably, said arcuate elements each comprise two feet, and one of the feet of each of two successive arcuate elements bear on the sub-floor stretcher in alignment with the same structural crosspiece.

According to a preferred embodiment of the invention, the longitudinal members and the under-stretchers being longitudinal structural elements, and the arched force distribution elements showing a lower surface and an upper surface, the vehicle is remarkable in that the device for protection further includes:

- at least one absorption element of a first type configured to fill the space between the underside of an arched element and the longitudinal structural element disposed opposite, preferably between the underside of an arched element and the sub-floor stretcher; and or

- at least one absorption element of a second type configured to fill the space between the upper surfaces of two arcuate elements arranged successively in the longitudinal direction of the vehicle and the longitudinal structural element disposed opposite, preferably between the upper surfaces of two arcuate elements successively arranged in the longitudinal direction of the vehicle and a spar.

The presence of absorption elements filling the spaces between the arched element or elements and the spar or the sub-floor stretcher improves the performance of the arched elements and adds a shock absorption function to the protection device. .

The lower surface is defined as the inner, concave surface of the arch (i.e., the arched element). The upper surface is defined as the external and convex surface of the arch (i.e. the arched element).

Preferably, at least one absorption element of a first type and / or at least one absorption element of a second type has an arrangement of internal ribs forming a trellis or a triangulated system. This configuration makes it possible to give the absorption elements the mechanical resistance necessary for their function.

Advantageously, at least one absorption element of a first type and / or at least one absorption element of a second type is made of plastic or composite material. In this way, it is possible to optimize the weight of the absorption device.

The absorption elements of a first type and of a second type can be similar, both from the point of view of their structure, of the material of which they are composed, or of their dimensions.

Optionally, at least one absorption element of a first type and / or at least one absorption element of a second type is fixed to an arcuate element, preferably by gluing. Alternatively, the absorption elements are fixed to the vehicle body on the floor, a side member, and / or a sub-floor stretcher.

The arched elements are advantageously fixed in position. Also, advantageously, the longitudinal members and the sub-floor stretchers being longitudinal structural elements and the vehicle further comprising a floor, the vehicle is remarkable in that the arched force-distributing element comprises:

- at least one hole for the passage of a screw for attachment to the floor; and or

- At least one fixing tab for its attachment to a longitudinal structural element and / or to a structural cross member. Preferably, the arcuate force distribution element comprises two feet and at least one of its feet is provided with a fixing tab.

Those skilled in the art will benefit from the fact that the arched element has sufficient strength to respond to its function of transmission and distribution of forces received. To this end, the arcuate force distribution element can be made of a metallic material. Preferably, the arcuate element is made of steel or aluminum. Advantageously, it is a solid element.

As will be understood, the arched element or elements are advantageously fixed to the vehicle floor or to the sub-floor stretcher. Indeed, in order to facilitate the installation of the protection device, the arched element is not in contact with the spar, so that a clearance remains between the spar and the arched element. The spar and the arched element nevertheless come into contact with each other in the event of an impact. Also, advantageously, the arcuate element for distributing forces comprises a vertex, and said arcuate element is arranged so that its vertex is placed facing the spar, and so that there remains a spacing between said vertex and said spar.

According to a second aspect, the invention provides a vehicle according to the first aspect remarkable in that it further comprises at least one absorption element of a third type configured to fill a space between the sub-floor stretcher and the battery. , preferably:

- at least one absorption element of a third type is made of plastic or composite material; and / or at least one absorption element of a third type has a honeycomb structure. Such a configuration provides an additional level of protection for the battery.

According to a third aspect, the invention relates to a vehicle protection device according to the first aspect, remarkable in that it comprises at least one arcuate force-distributing element comprising two feet, a lower surface and an upper surface. Preferably, it further comprises:

at least one absorption element of a first type fixed on the underside of an arched element; and or

- at least one absorption element of a second type fixed to the upper surface of said arched element; and or

- At least one fixing tab, preferably arranged on one of its feet.

The invention will be well understood and other aspects and advantages will appear on reading the following description, given with reference to the accompanying drawing plates in which:

Figure 1 shows the locations of a protection device according to the invention and a third type absorber.

- Figure 2 is a perspective view showing a protection device and third type absorbers in place in the vehicle.

- Figure 3 is a representation of an arcuate element.

- Figure 4 is a representation of a protection device.

- Figure 5 is a representation of a first type absorber.

- Figure 6 is a representation of a third type absorber.

In the description which follows, the term “understand” is synonymous with “include” and is not limiting in that it authorizes the presence of other elements in the device, the assembly or the vehicle to which it makes reference. It is understood that the term "understand" includes the terms "consist of". The terms “front” and “rear” as well as the “longitudinal” and “transverse” directions will be understood in relation to the general orientation of the vehicle. The term "lower" will indicate greater proximity to the ground than the term "upper". In the various figures, the same references designate identical or similar elements.

The invention relates to a motor vehicle provided with a propulsion battery and a device for protecting such a battery. Figure 1 is a partial view in cross section of a vehicle capable of accommodating such a protection device. The vehicle is of the hybrid or electric type and comprises a spar 1 and a sub-floor stretcher 3 on each lateral side of the vehicle. The longitudinal members 1 and the sub-floor stretchers 3 are structural elements of the vehicle extending in its longitudinal direction. The vehicle further comprises a propulsion battery 5. The battery 5 is advantageously wrapped in a protective shell 7. It is disposed under the floor 9 of the vehicle, preferably under the front floor and in particular under the rear passenger seats. Structural sleepers 11 are arranged under the battery 5 and extend between the sub-floor stretchers in a direction transverse to the vehicle. The structural crosspieces 11 are connected to the sub-floor stretchers 3. There are therefore two spaces (13, 15) that the invention will exploit by filling them with protective devices and, optionally, absorbers. A first usable space 13 is located between the side rails 1 and the sub-floor stretchers 3 which are arranged opposite. A second usable space 15 is located between the battery 5 and each of the sub-floor stretchers 3. The invention is remarkable in that the vehicle comprises at least one battery protection device (not visible in FIG. 1) and in that at least one battery protection device is disposed in the space 13 existing between one of the side members 1 and the sub-floor stretcher 3 placed opposite said side member 1.

In FIG. 2, the protective device 17 is shown in its housing, that is to say the sub-floor space existing between one of the side members 1 and the sub-floor stretcher 3 placed opposite said side member 1.

As can be seen, said battery protection device 17 comprises at least one arcuate element 19 for distributing forces. As illustrated in FIG. 3, each arched element comprises an arch having two support legs 21 and a top 23.

The arcuate elements 19 are advantageously fixed in position in their housing. According to a preferred embodiment, they are fixed by their feet 21 to the sub-floor stretcher 3. To do this according to a preferred embodiment (illustrated in Figure 2), they have a fixing tongue 25 (not visible in the figure 3) which is placed as an extension of their feet and which allows fixing by screwing on the sub-floor stretcher. The invention thus takes advantage of the presence of screws 27 intended for fixing the structural crosspieces 11 on the sub-floor stretcher to fix the three elements together by the same fixing means, the end of a structural crosspiece 11 then being sandwiched between the sub-floor stretcher 3 and a fixing tab 25 of the protection device 17.

Other means of fixing the arched elements 19 can be envisaged. For example, they can be fixed by gluing or they can be screwed or clipped on the underside of the floor. When screwed to the floor, the arched elements will have at least one hole 29 for the passage of a screw.

Those skilled in the art will have the advantage that the arcuate element or elements 19 have sufficient strength to meet their function of transmission and distribution of received forces. To this end, at least one arcuate element 19 for distributing forces can be made of a metallic material. Preferably, at least one arcuate element 19 is made of steel or aluminum. When it is made of a metallic material, an arcuate element 19 may have lightening holes 31. Preferably, at least one lightening hole is also used for fixing by screwing the arcuate element 19 to the floor 9 of the vehicle.

Preferably, in order to facilitate its positioning, said arcuate element 19 is arranged so that there remains a spacing between its apex 23 and the beam 1 placed opposite the apex 23. Nevertheless, this spacing will be as small as possible, by example it represents a play of a few millimeters.

As can be seen in FIG. 1 and in FIG. 4, the protection device comprises a plurality of arcuate elements 19 which follow one another in the longitudinal direction of the vehicle. The various arched elements 19 may have come in one piece and form a single assembly showing a plurality of successive feet and arches. Preferably, to facilitate their installation and their manipulation, the arched elements 19 each comprise an arch and two feet. FIG. 4 shows a protection device which can be installed in a vehicle showing four structural crosspieces.

In Figure 2, it is understood that two successive arched elements 19 will be placed as an extension of the same structural cross member 11. The cord of the arched members is therefore advantageously at least equal to the distance between two structural cross members 11. The width of a foot 21 of an arched element 19 (aligned with a structural cross member 11) is advantageously less than the width of the structural cross member 11. The top 23 of the arched member 19 is disposed between two structural cross members 11 in the longitudinal direction of the vehicle. The top 23 of the arched element 19 is arranged facing the side member, halfway between two structural crosspieces 11.

However, a reverse orientation of the arcuate elements is possible. Their top is then placed in alignment with the ends of the structural crosspieces and their feet are placed opposite the spar. Whatever the orientation chosen for the arched elements, it is important to place their feet or their summit in extension of the structural crosspieces, in order to allow a transmission of forces towards said structural crosspieces.

It will be understood that when the protection device is oriented so that the tops of the arched elements are arranged facing the sub-floor stretchers, the fixing tabs 25 are advantageously arranged at the level of the tops so as to fix the tops on the under-stretcher. floor and / or a clearance is present between the feet of the arched elements and the side member disposed opposite.

According to a preferred implementation of the invention, the spaces between the arched elements 19 and the spar 1 and the spaces between the arched elements 19 and the sub-floor stretcher 3 are filled with absorption elements (33, 35) . Also, preferably, the protection device 17 comprises at least one absorption element of a first type 33 configured to fill the space between the lower surface of the arched element 19 and the longitudinal structural element disposed opposite (here the sub-floor stretcher 3). Alternatively or additionally, the protection device 17 comprises at least one absorption element of a second type 35 configured to fill the space between the upper surfaces of two successive arched elements 19 in the longitudinal direction of the vehicle and the element of longitudinal structure arranged opposite (here the spar 1).

Preferably, at least one absorption element of a first type 33 and / or at least one absorption element of a second type 35 is made of plastic or composite material and has an arrangement of internal ribs 37 forming a trellis or a triangulated system. FIG. 5 illustrates an exemplary embodiment of an absorption element of a first type 33 showing such a system of internal ribs 37. Other structures can be envisaged by a person skilled in the art such as a cellular structure for example, or still a very dense foam.

Advantageously, at least one absorption element of a first type 33 and / or at least one absorption element of a second type 35 is fixed to an arcuate element 19, preferably by gluing. It is possible to pre-glue the absorption elements (33, 35) to the arched elements 19 before mounting them on the vehicle.

The absorption elements (33, 35) can be made of a thermoplastic or thermosetting composite material. A preferred implementation of the invention will favor the use of thermoplastic matrices which have higher delamination and rupture limits than thermosetting resins.

The manufacture of the absorption elements (33, 35) of thermoplastic material can be done, for example, by injection or by any other process known to those skilled in the art. Whatever the manufacturing process chosen, those skilled in the art will benefit from selecting the thermoplastic polymer matrix from one or more materials chosen from polypropylene (PP), polyphthalamide (PPA), polyetheretherketone (PEEK), phenylene polysulfide. (PPS), polyamide-imide (PAI), polyetherimide (PEI), polyarylamide (PAA), or polyamide (PA) such as for example polyamide 6 (PA 6 or polycaprolactam) or polyamide 6.6 (PA 6.6 or polyhexamethylene adipamide). Preferably, the polymer matrix will be a polyamide (PA).

The manufacture of the device in thermosetting material can be done according to the techniques known from RTM (Resin Transfer Molding) or SMC (Sheet Molding Compound) for example. The resins used can be selected from polyepoxide resins, unsaturated polyester resins, vinylester resins, copolymers such as polyester-vinylester resins.

Preferably, the composite material used (with a thermoplastic or thermosetting matrix) comprises a reinforcement (or filler) in fibers or in a mixture of fibers selected from natural glass, carbon, ceramic, graphite fibers such as fibers flax, hemp or bamboo, organic polymers such as polyester fibers. Preferably, the fibers used in the composite material are glass and / or carbon fibers.

Optionally, the absorption elements (33, 35) may have local reinforcement elements. For example, the local reinforcing elements may be present on the external surface of said absorption elements.

The protective device operates as follows. When the vehicle collides with a post in front of a structural cross member 11, the spar 1 will deform and press in compression on the absorption element of a second type 35 placed opposite, which will absorb a portion crash impact energy on itself. At the end of the crushing, the absorption element of a second type 35 will transmit part of the forces received to the legs of the arcuate elements arranged on either side. Then, the forces will be transmitted to the structural cross member 11.

When the vehicle collides with a post between two structural crosspieces 11, the spar 1 will deform and press in compression on the arched element 19 disposed opposite. The arched element 19 will deform, transmitting part of the forces to the structural crosspieces 11 via the feet 21. The deformation of the arched element will press on the absorption element of a first type 33 which will absorb part of the impact energy by crushing on itself.

In order to respond to violent impact situations, a person skilled in the art will have the advantage that the vehicle also comprises at least one absorption element of a third type 39 5 configured to fill a space 15 (visible in FIG. 1 ) between the sub-floor stretcher 3 and the battery 5. Preferably, as illustrated in FIG. 6, at least one absorption element of a third type 39 is made of plastic or composite material and has a cellular structure, for example of the type Honeycomb. Such a configuration makes it possible to offer an additional level of protection to the battery 5. The composite material and / or the internal structure can be similar to those chosen for the first 33 and / or second 35 types of absorbers.

The absorption element of a third type can also be made of dense foam. The foam can be chosen from a polyether, polyester, polypropylene, polyethylene or polyurethane foam, preferably a polyethylene foam. For example, the foam may be an expanded polyethylene foam of the NEOPOLEN® type.

The protective device 17 is advantageously symmetrical and able to be mounted both on the right lateral side than the left lateral side of the vehicle.

Claims (10)

1. Motor vehicle of the hybrid or electric type, the structure of which comprises, at each of its lateral sides, a spar (1) arranged parallel to a sub-floor stretcher (3); the vehicle further comprising a propulsion battery (5) and at least one battery protection device (17); the vehicle being characterized in that a battery protection device (17) is disposed between said spar (1) and said sub-floor stretcher (3) and in that said protection device (17) comprises at least one element arched (19) force distribution. 2. Vehicle according to claim 1, the vehicle comprising two sub-floor stretchers (3) and at least two structural sleepers (11) extending between said under-stretchers (3) in the transverse direction of the vehicle, the vehicle is characterized in that at least one arcuate element (19) for distributing forces comprises two legs (21) and in that it is arranged so that said legs (21) are placed in abutment on the sub-floor stretcher (3) in alignment with said structural sleepers (11). 3. Vehicle according to claim 1 or 2, the vehicle comprising two sub-floor stretchers (3) and at least three structural sleepers (11) extending between the sub-floor stretchers (3) in the transverse direction of the vehicle, the vehicle is characterized in that it comprises at least two arcuate elements (19) for distributing forces arranged to succeed one another in the longitudinal direction of the vehicle, preferably said arcuate elements (19) each comprise two feet (21), and one of the feet (21) of each of two successive arched elements (19) bear on the sub-floor stretcher (3) in alignment with the same structural crosspiece (11). 4. Vehicle according to one of claims 1 to 3, the side members (1) and the under-floor stretchers (3) being longitudinal structural elements, and the arched elements (19) of force distribution showing a lower surface and an upper surface , the vehicle is characterized in that the protection device (17) further comprises: - at least one absorption element of a first type (33) configured to fill the space between the lower surface of an arched element (19) and the longitudinal structural element (1, 3) arranged opposite, preferably between the lower surface of an arched element (19) and the sub-floor stretcher (3); and or - at least one absorption element of a second type (35) configured to fill the space between the upper surfaces of two arched elements (19) arranged successively in the longitudinal direction of the vehicle and the longitudinal structural element (1, 3) arranged opposite, preferably between the upper surfaces of two arcuate elements (19) arranged successively in the longitudinal direction of the vehicle and a spar (1). 5. Vehicle according to claim 4, characterized in that: - at least one absorption element of a first type (33) and / or at least one absorption element of a second type (35) has an arrangement of internal ribs forming a trellis or a triangulated system; and or - at least one absorption element of a first type (33) and / or at least one absorption element of a second type (35) is made of plastic or composite material; and or - at least one absorption element of a first type (33) and / or at least one absorption element of a second type (35) is fixed to an arcuate element (19), preferably by gluing. 6. Vehicle according to claim 1 to 5, the side rails (1) and the sub-floor stretchers (3) being longitudinal structural elements and the vehicle further comprising a floor (9), the vehicle is characterized in that l arcuate element (19) for distributing forces comprises: - at least one hole (29) for the passage of a screw for attachment to the floor (9); and or - at least one fixing tab (25) for fixing to a longitudinal structural element (1,3) and / or to a structural cross member (11); preferably the arcuate element (19) for distributing forces comprises two feet (21) and at least one of its feet (21) is provided with a fixing tab (25). 7. Vehicle according to claim 1 to 6, characterized in that the arcuate element (19) of force distribution is made of a metallic material, preferably the arcuate element (19) is made of steel or aluminum. 8. Vehicle according to claim 1 to 7, characterized in that the arcuate element (19) for distributing forces comprises a top (23) and in that said arcuate element (19) is arranged so that its top (23 ) is placed opposite the beam (1), and so that there remains a spacing between said top and said beam (1). 9. Vehicle according to one of claims 1 to 8, characterized in that it further comprises at least one absorption element of a third type (39) configured to fill a space between the sub-floor stretcher (3 ) and the battery (5), preferably: - at least one absorption element of a third type (39) is made of plastic or composite material; and or - at least one absorption element of a third type (39) has a honeycomb structure 10. Protective device (17) for a vehicle according to one of claims 1 to 8, characterized in that it comprises at least one arcuate element (19) for distributing forces comprising two feet (21), a lower surface and an upper surface, preferably it further comprises: - at least one absorption element of a first type (33) fixed on the lower surface of an arched element (19); and or - at least one absorption element of a second type (35) fixed to the upper surface of said arcuate element (19); and or - at least one fixing tab (25), preferably arranged on one of its feet (21).