Abstract:
A motor vehicle battery supporting structure configured to be attached and fixed to the body structure of this vehicle, and to carry a battery in a form of a frame to surround the battery, the frame having in its center an opening suitable for insertion of the battery, and a first battery locking mechanism is provided on the frame so as to allow the battery to be locked to and unlocked from the frame.

Description:
BACKGROUND 
     The present invention relates to a motor vehicle battery supporting structure. 
     Means for fixing batteries in electric vehicles are known, in particular from document WO 2007049127. These batteries, assemblies of “stacks”, have the form of a casing secured to side members of the vehicle via intermediate fixing means. 
     Conventionally, these batteries are located in the front unit of the vehicle, spaced apart from the front end in order to protect the battery from any deformation of the structure during an impact. They can also be located under the vehicle and thus be protected from a frontal or rear impact. In the case of a battery that has to be located close to one longitudinal end of the vehicle, and for example when a battery is located at the rear of the vehicle, it is advisable to take particular account of the supporting environment of this battery in order that an impact against the vehicle cannot damage this battery and consequently represent a danger to the user. 
     BRIEF SUMMARY 
     One of the objectives of the invention is thus to provide a motor vehicle battery supporting structure that protects the battery from impacts suffered by the vehicle. A further objective is to present a supporting structure allowing quick and easy handling of the associated battery, in particular with a view to exchanging batteries on a single supporting structure. Thus, the battery supporting structure is designed to have the functions that make this exchangeability possible, such as the locking, connections, and sealing of the battery with respect to the vehicle. 
     In response to these objectives, which are encountered invariably with the various motor vehicle manufacturers, the present invention is also intended to have a low cost and to take up little space. 
     In order to meet these objectives, the invention provides a motor vehicle battery supporting structure, able firstly to be attached and secured to the bodyshell structure of this motor vehicle and secondly to carry a battery, characterized in that this supporting structure has the form of a frame able to surround the battery, the frame having in its center an opening suitable for fitting the battery, and characterized in that first battery locking means are carried on the frame such that the battery can be locked and unlocked on this frame. 
     The invention is defined in a more precise manner by the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features and advantages of the invention will become apparent from reading the following detailed description, in order to understand which reference is made to the appended drawings, in which: 
         FIG. 1  is a bottom view of a vehicle rear underframe, provided with a battery supporting structure according to the invention; 
         FIG. 2  is a view of the battery supporting structure in  FIG. 1  and of the associated battery; 
         FIG. 2   a  is an enlargement of  FIG. 2 , showing specifically an indexing means of the battery in the supporting structure according to the invention; 
         FIG. 3  is a diagram of the assembly formed in the vehicle by a battery and a supporting structure according to the invention, in a view from below the vehicle; 
         FIG. 4  shows a top view of the frame forming the battery supporting structure according to the invention; 
         FIG. 5  is a side view of the battery supporting structure in  FIG. 1  and of the associated battery; 
         FIG. 6  is a top view of the fairing secured to the battery according to the invention; 
         FIG. 7  is a bottom view of the vehicle underframe, indicating the position of section views showing more specifically the butted joints of the supporting structure against the vehicle bodyshell. 
     
    
    
     DETAILED DESCRIPTION 
     As shown in the figures, a battery supporting structure is attached and secured to the bodyshell structure  4  of the vehicle and is in the form of a frame  10 , the form and dimensions of which are suitable for fixing this frame  10  firstly to side members  44 ,  46  and secondly to cross members  41 ,  42  forming structural elements of the vehicle that are approximately perpendicular to the side members. Thus, in a general manner, the frame  10  extends approximately horizontally and transversely between the left-hand side member and the right-hand side member, at the front or the rear depending on the location at which the battery is installed, respectively in the front unit or in the rear unit of the vehicle. 
     According to the example shown in  FIG. 1  relating to the installation of a battery  2  and a supporting structure according to the invention in a vehicle rear unit, the frame  10  forming this supporting structure is attached and screwed under the left-hand and right-hand rear side members  44 ,  46 , under a specific rear cross member  41 , and under a central underframe cross member  42 . This installation takes place taking account of the architecture of the rear axle assembly, represented in particular by a rear axle-assembly cross member  5  and shock absorbers  7  located between the bodyshell and the wheel supports. 
     The center of the frame  10  has an opening suitable for fitting a battery  2 , this battery being able to engage with the frame  10  in order to lock the battery  2  in position with respect to the frame  10  and thus with respect to the bodyshell structure  4 . According to the diagram in  FIG. 3 , the stack of these components is as follows, namely, from top to bottom, a bodyshell structure  4  of the vehicle, a frame  10  secured to this bodyshell structure  4 , having first sealing means  61  located between the bodyshell  4  and the frame  10 , and finally a battery  2  locked under the frame  10 , second sealing means  62  being located between the battery  2  and the frame  10 . 
     First locking means  13  are carried on the frame  10  and have a form that is complementary with second locking means  23  secured to the battery  2 . The engagement of these first and second locking means fixes the battery with respect to the supporting frame  10  when the battery is in the position desired by the operator. 
     As shown, these first locking means  13  can have the form of hooks or a latch, intended to hook locking or striker lugs distributed around the periphery of the battery and forming the second locking means  23 . It will be understood that the battery  2  can be surrounded and carried by a fairing  22 , shown by way of example in  FIG. 6 , and that it is on this fairing  22  that the second, abovementioned locking means  23  can in particular be formed. This fairing  22  can be formed from aluminum and could have particular thermal characteristics on account of carrying the battery  2 . 
     The precision of assembly between the battery  2  and the supporting frame  10  is achieved by positioning the battery by reference to guides and rings integrated into the frame and by indexing means, which are shown in  FIG. 2   a  and are in the form of indexing pins  33  that are integrated into the battery and are guided into holes formed in the lower face of the frame  10 . These indexing pins  33  also stop movement in translation longitudinally and transversely during impacts. 
     The precision of assembly between the supporting frame  10  and the bodyshell structure  4  is achieved by guide pins  35  located on the upper face of the frame  10  and able to engage with arrangements of the bodyshell structure. 
     These indexing and guide pins also fulfill an anti-burst function by stopping longitudinal and transverse movement in translation during impacts, firstly of the frame  10  with respect to the bodyshell structure  4  and secondly of the battery  2  with respect to the frame  10 . 
     It will be understood that the position of the locking means  13 ,  23  and of the indexing means  33  on the frame  10  is calculated to hold the battery  2  in an optimized manner with respect to the frame  10 . The fact that there are four locking means located around the periphery of the frame  10  means that the battery and the associated fairing  22  are held strongly. However, without departing from the context of the invention, this number of locking means could be different and the position thereof could be modified. In all these cases, the locking means are designed to hold tension during forces produced by movements of the battery  2  relative to the supporting frame  10  under the effect of a sudden deceleration in particular during impacts. 
     The battery  2  is positioned with respect to the frame  10  such that this battery is completely surrounded by the frame  10  and extends vertically both above the frame  10  and below it. The architecture of the vehicle dictates in the figures that the battery  2  is located substantially below this frame  10 , but this frame  10  is high enough for the rocking of the battery with respect to the frame  10  and to the bodyshell of the associated vehicle during an impact to be controlled, as shown in  FIG. 5 . 
     The frame  10  is formed by a hollow body dimensioned with respect to the excitation mode for acoustic performance and for endurance, it being possible for this hollow body to be produced in one piece by casting, or in a plurality of pieces by drawing for example, either from aluminum or from steel. 
     As shown in particular in  FIG. 4 , the frame  10  has an approximately rectangular rear part that is formed by a first transverse element  11 , able to be located under the rear cross member  41  of the vehicle structure, and by two lateral elements  14 ,  16  that are approximately perpendicular to the first transverse element  11  and are able to be located under the side members  44 ,  46  of the vehicle. The frame  10  also has a front part, extending the rear part approximately in the same plane, said front part being in the form of a trapezoid with a second transverse element  12  forming the short base approximately parallel to the first transverse element  11 , this second transverse element  12  being able to be located under the central cross member  42  of the vehicle structure. This second transverse element  12  attached to the lateral elements  14 ,  16  of the rear part of the frame  10  by oblique elements  18 ,  19  that are able to be located under the shock absorber clevises. 
     The frame  10  has the form of an approximately planar and horizontal hollow body, except for the second transverse element which has a wave form, this arrangement being produced in order to position the sealing ring for high-tension and low-tension cables to pass through from the underframe to a sealed region of the vehicle. However, the frame is approximately planar overall. In addition, it completely surrounds the battery and passes around the entire perimeter thereof at its side walls, in such a way that a part of the battery protrudes above and below the frame or is able to protrude in this way in the event of an impact, as illustrated in  FIG. 5 . The respective locking means of the battery and of the frame are thus located at an intermediate height of the battery. 
     The presence of the frame  10  makes it possible to envision attaching ancillary elements of the battery to this frame  10 , in particular a protective bell housing attached to the frame  10 . This protective bell housing makes it possible to manage the soundproofing and the dirt-proofing and also isolates the magnetic field generated by the battery. The protective bell housing is thus welded to the frame  10  and extends above the frame  10 , while still enabling the battery  2  to be mounted through the frame  10 , from underneath the latter. 
     The battery supporting structure according to the invention thus has the combined advantage of automating the replacement of the batteries while providing protection for the battery and also stiffening the general structure of the bodyshell. The automation of replacing the batteries is made possible by the referencing of the vehicle during a change of battery by the indexing of this battery on the frame secured to the bodyshell.