FR3113784A1 - BATTERY MOUNTING SYSTEM - Google Patents

Abstract

[fixing system comprising:- a battery,- an airtight casing (2, 3, 4, 13) comprising a wall delimiting an internal space containing the battery, and forming a thermal convection air space around the battery,- a first fixing means (9) of the battery in the hermetic casing (2, 3, 4, 13), - a second fixing means (11, 12, 14) of the hermetic casing (2, 3, 4,13) on a support, this second fixing means (11, 12, 14) comprising a protuberance (11) of the wall forming a complementarity of shape with the support. Figure 1

Description

BATTERY MOUNTING SYSTEM

The present invention relates to a shock-resistant fastening system for a battery of a motor vehicle.

More specifically, this fixing system comprises the battery and a hermetic casing surrounding the battery, and a means for fixing this hermetic casing to a structure of the vehicle.

Motor vehicles having a heat engine generally comprise one or more batteries connected to the on-board network, also called service batteries, to supply the equipment of these vehicles, in particular a starter of a heat engine. Other vehicles, if they have electric or hybrid propulsion, include one or more traction (or propulsion) batteries connected to a power network to supply the electric traction (or propulsion) motors.

Battery will therefore be understood throughout the text of this document as an assembly comprising at least one battery module containing at least one electrochemical cell, the service battery being considered equivalent to at least one module. This battery optionally comprises electrical or electronic means for managing the electrical energy of this at least one module. When there are several modules, they are grouped together in a housing and then form a battery block, this battery block being often designated by the English expression "battery pack", this housing generally containing a mounting interface, and terminals for connection.

Furthermore, the term electrochemical cell will be understood throughout the text of this document to mean cells generating current by chemical reaction, for example of the lithium-ion (or Li-ion) type, of the Ni-Mh or Ni-Cd or still lead.

The capacity and power of these batteries are constantly increasing, in particular thanks to lithium-ion “Li-ion” technology. However, this type of batteries poses problems related to the operating temperature.

Indeed, lithium-ion batteries have limited performance with negative temperatures, and high temperatures degrade them quickly.

To improve their operation when cold, it is possible to modify the materials of the electrodes, or the electrolyte, but these solutions can degrade certain performances of the batteries, in particular when hot, which reduces their service life. It is also possible to provide a larger number of cells in parallel. These different solutions significantly increase battery costs.

Another solution is to regulate the temperature of these batteries. For example, document FR-A1-2987499 discloses an air conditioning system for a service battery of a motor vehicle, comprising the hermetic casing provided to receive the battery, this receptacle having at one end an air inlet, and at a second end an air vent.

This system is satisfactory, but the battery is no longer directly attached to the structure of the vehicle, the hermetic casing taking on this new function.

To achieve the fastening system of this hermetic casing on the structure of the vehicle, it is known to strap a casing, or to encircle it with a metal hoop, both comprising clamping means.

For example, patent document US-A1-4 098 366 discloses a casing for a battery, this battery being housed in the passenger compartment of a vehicle. Although the problem here is linked to the escape of toxic fumes from the battery that the occupants of the vehicle must not breathe, this document nevertheless presents a casing fixed by a strap comprising a flexible part, a rigid part, and a means of strap tightening.

Unfortunately, in addition to the fact that a strap has poor resistance to shocks because it is flexible enough to allow the casing to move, such fastening systems are complex to implement when mounting the battery in the vehicle:
- the flexible parts of the strap cause the attachment system to be poorly positioned, and require that the attachment system not be present when positioning the casing in the vehicle,
- the clamping means is bulky whereas the casing already takes up more space than a simple battery without casing,
- even if the strap is replaced by an entirely rigid attachment system, this attachment system must always be fitted after the casing and the battery have been fitted in the vehicle, thus generating an additional fitting operation and additional parts.

The object of the invention is to remedy at least one of these drawbacks, in particular by optimizing such a fixing means.

To this end, the subject of the invention is a fastening system comprising:
- a battery,
- a hermetic casing comprising a wall delimiting an internal space containing the battery, and forming a thermal convection air gap around the battery,
- a first means for fixing the battery in the hermetic casing,
- a second means of fixing the hermetic casing on a support,
this second fixing means comprising a protuberance of the wall forming a complementarity of shape with the support.

The term "air gap" will be understood throughout the text of this document, the air in contact with the battery and exchanging calories with the battery, air which is also guided between the battery and the internal face of the wall of the hermetic casing opposite the battery. This air is in motion and therefore imposes a heat exchange by convection with the battery. This hermetic casing comprises for example a fan imposing an air inlet through an inlet opening of the hermetic casing opening into the air gap, this air emerging through an air outlet opening of the hermetic casing. But other variants are possible, such as for example a movement of air imposed by a dynamic pressure of the air due to a forward movement of the hermetic casing in the air, for example when it is on board a vehicle. moving.

The term "hermetic casing" will be understood throughout the text of this document to mean an airtight casing with the exception of the air inlet and outlet opening described above.

Thus this set of hermetic casing and battery is fixed on the support very quickly and in a very simple assembly operation comprising a step of fitting the protuberance into the support. This operation is much easier than a strap attachment, and involves far fewer parts. In addition, the first fixing means and the second fixing means being independent, the hermetic casing becomes conditionable with the battery already fixed in the internal space of the hermetic casing, summing up the mounting operation on the support to the mounting of a only together: the hermetic casing on the support.

According to one embodiment of the invention, the protuberance comprises stiffening ribs.

These ribs make it possible to withstand significant forces, which is advantageous for an application in the automotive field. Indeed, this protrusion thus reinforced makes it possible to withstand shocks, in particular when this vehicle collides against an obstacle. The hermetic casing, and therefore the battery, are then kept attached to the support even after the impact.

According to one embodiment of the invention, this protuberance is an edge of the hermetic casing forming a shoulder.

According to one embodiment of the invention, the hermetic casing comprises a hole, and the second fixing means comprises a screw passing through this hole and capable of being engaged in the support.

According to one embodiment of the invention, the first fastening means comprises a heel of the battery and a housing in the wall, this heel of the battery being embedded in this housing.

According to one embodiment of the invention, this housing is a depression in the internal face of the wall, the protrusion being produced by the external face of the wall facing this depression.

This arrangement is particularly compact and has the advantage of using the mechanical resistance of the battery during the impact. Indeed, the vis-à-vis means that the wall is only stressed in compression on its thickness, between the protrusion and the depression, allowing a significant reduction in the hermetic casing. The heel of the battery is then mechanically stressed by the second fixing means, these stresses passing through the thickness of the wall to the heel of the battery.

According to one embodiment of the invention, the first fixing means comprises a plate screwed onto the internal face of the wall and resting on the heel of the battery.

According to one embodiment of the invention, the internal face of the wall comprises a network of ribs projecting towards the internal space.

This network of ribs makes it possible, in addition to the advantage of stiffening the wall, to create a turbulent air flow regime, thus promoting heat exchange between the air and the coil.

According to one embodiment of the invention, the network of ribs forms a honeycomb network.

The invention further relates to a vehicle comprising:
- a support,
- a battery,
- a hermetic casing comprising a wall delimiting an internal space containing the battery, and forming a thermal convection air gap around the battery,
- a first means for fixing the battery in the hermetic casing,
- a second means of fixing the hermetic casing on the support,
this vehicle comprising a fastening system as previously described.

Advantageously, this battery is a service battery of the vehicle, in particular a lithium-ion type battery.

Other characteristics, objects and advantages of the invention will appear on reading the description of the non-limiting examples of embodiment which will follow, made with reference to the appended figures 1 to 4, which represent:

shows an exterior three-dimensional view of an assembled fastening system, according to a first variant of the invention.

represents an exploded three-dimensional view of a fastening system according to the first variant of the invention.

shows a cross-sectional diagram of a fastening system according to the invention according to a second variant.

shows a sectional diagram of a fastening system according to the invention according to a third variant.

It should be borne in mind that the figures are given by way of examples and do not limit the invention. They constitute schematic representations of principle intended to facilitate understanding of the invention and are not necessarily at the scale of practical applications. Furthermore, in what follows, reference is made to all the figures taken in combination. When reference is made to a specific figure or figures, these figures are to be taken in combination with the other figures for the recognition of the designated reference numerals. The references of the unchanged elements or having the same function are common to all the figures, and the variant embodiments.

The assembly shown in Figures 1 to 4 comprises a fastening system comprising:
- a battery 1, shown only in Figures 3 and 4 by dotted lines,
- a hermetic casing 2, 3, 4, 5, 13 comprising a wall 5 delimiting an internal space 6 containing the battery 1, and forming an air gap 7 for thermal convection around the battery 1,
- a first fixing means 8, 9, 10 of the battery 1 in the hermetic casing 2, 3, 4, 5, 13,
- a second fixing means 11, 12, 14 of the hermetic casing 2, 3, 4, 5, 13 on a support 20,
this second fixing means 11, 12, 14 comprising a protuberance 11 of the wall 5 forming a complementarity of shape 23 with the support 20.

The protrusion 11 comes from the wall 5.

This hermetic casing 2, 3, 4, 5, 13 is airtight, as previously indicated in the general definition. The air gap 7 is therefore a space preserved between the battery 1 and an internal face of the wall 5 of the hermetic casing 2, 3, 4, 5, 13. This space is advantageously 10 mm thick, but according to the available space can be reduced by up to 5mm or, on the contrary, enlarged by up to 50mm. More precisely, the battery 1 complies with the general definition which has already been explained previously. This battery 1 corresponds in the non-limiting example of the figures to a parallelepiped battery with electrochemical cells of the lithium-ion type replacing a lead battery. The air gap 7 is then the space preserved between at least three faces of the battery 1 and the internal face of the wall 5.

This hermetic casing 2, 3, 4, 5, 13 comprises an air inlet opening topped by a fan 18 sucking in ambient air and pushing it back into the air gap 7, the air inlet opening air emerging into the air gap 7. As a variant or in combination, this fan 18 is for example reversible and can also suck the air from the air gap 7 to discharge it outside the hermetic casing 2, 3 , 4, 5, 13. This hermetic casing 2, 3, 4, 5, 13 further comprises an air outlet from the air gap 7, capped by a sleeve 19 channeling this air outwards or towards a device of the heat exchanger type, for example.

It will be noted that for FIGS. 3 and 4, the hermetic casing 2, 3, 4, 5, 13, just like the support 20 and the complementary form 23, are simply schematized, and represented by a single line. It is implicit that the wall 5 has for example a thickness, just like the support 20.

The figures further illustrate the hermetic casing 2, 3, 4, 5, 13 in the form of a shell 2 comprising a tray 4 to receive the battery 1, and a cover 3 for closing the tray 4. The watertightness The air between this cover 3 and the tray 4 is for example ensured by the interposition of a seal 22, but other devices are possible such as for example an adjustment between the cover 3 and the tray 4.

The joining plane between cover 3 and tray 4 is a diagonal plane between two corner vertices of one face of the parallelepipedic battery 1. This arrangement has the advantage of being able to slide the battery 1 on the bottom of the tray 4, and therefore without having to lift it, which improves the ergonomics of a mounting station for this battery.

This battery 1, for example service, finds a particular application in the automotive field. When it is on board a vehicle, the bottom of the tray 4 has a face resting on the support 20, this face representing for example the underside of the fixing system, and the cover 3 the top of the fixing system, but this is not mandatory, this face resting on the support 20 can be positioned other than horizontally, for example vertically.

This fan 18 comprises, for example, an electric heating resistor that can be controlled in the air flow of the fan 18. For example, the fixing system comprises a control device 16, in particular a computer, making it possible to control the fan 18 and the heating resistor. This computer 16 is advantageously fixed to the cover 3 by studs 17 or any other means, and thus benefits from cooling by air convection in the air gap 7 through the cover 3.

The cover 3 comprises an interface area 21 having an electrical connection terminal (not shown) coupled to a terminal of the battery 1. This electrical connection terminal may be the terminal of the battery itself, the interface area 21 being an opening of the cover 3 configured to encircle the terminal of the battery 1 in an airtight manner, this terminal projecting with respect to the top of the cover 3.

The support 20 is for example an element of a vehicle structure, in this case the body of the motor vehicle, in the compartment of an engine (not shown).

The protuberance 11 of the wall 5 forming a complementarity of shape 23 with the support 20 is a projecting shape of the wall 5, which is illustrated as an extension of the bottom of the tray 4, but this is not obligatory, this protuberance 11 possibly be located on the cover 3 or the tray 4, but preferably on the tray 4 given that the battery 1 rests on the bottom of the tray 4 and is also fixed there by the first fixing means 8, 9, 10. Thus in in the event of a vehicle impact, the mechanical stresses will pass only through tray 4 without passing through cover 3, cover 3 which can then be lightened, its sole function then being to ensure the tightness of the hermetic casing 2, 3, 4, 5, 13. In addition, the protuberance 11 in extension of the bottom of the tray 4 not only allows the mechanical stresses to pass only through the tray 4, but more advantageously to pass only through the bottom of the tray 4, again allowing a reduction, that tray 4, by only reinforcing as the bottom or the periphery of the bottom.

This protuberance 11 forms a shoulder. This shoulder comprises a first face coplanar with the bottom, and a second face opposite the first face and forming the sides of the shoulder. The second face can form an angle with the first face, so as to form a point, or also in this case a truncated point. This protrusion 11 therefore has the shape of a heel which is fitted into the complementary shape of the support 20, which allows immobilization of the hermetic casing 2, 3, 4, 5, 13 according to at least two orthogonal axes of translation, the first axis being parallel to the bottom, the second axis being orthogonal to the bottom. For a vehicle, this second axis is preferably a vertical axis.

Of course, the fixing system can comprise several protuberances 11 arranged between them so as to leave free only one degree of freedom according to a direction of translation parallel to the bottom, this direction of translation being the direction of assembly of the fixing system in the vehicle, but it is not compulsory and this fixing system can comprise a screw in addition to the protrusion 11, so as to eliminate the remaining degree or degrees of freedom: the hermetic casing 2, 3, 4, 5, 13 for example comprises a bore 13, the second fixing means 11, 12, 14 comprising a screw 14, symbolized by an axis line, and passing through this bore 13 and capable of being engaged in the support 20, in particular by the means of its thread.

The protuberance 11 comprises for example stiffening ribs 12, but this is not mandatory as will be shown in the variant of .

This protuberance 11 is for example an edge of the hermetic casing 2, 3, 4, 5, 13 forming the shoulder, in particular the heel. This border encircles for example the entire periphery of the background, but not necessarily. For example, the figures illustrate a border along part of this periphery, on one face of the tray 4 comprising the fan 18.

The first fastening means 8, 9, 10 comprises a heel 8 of the battery 1 and a housing 9 of the wall 5, this heel 8 of the battery 1 being embedded in this housing 9. This heel 8 of the battery 1 corresponds to the description of the preceding stub, but this stub 8 of battery 1 is a protuberance of battery 1.

There , like Figures 1 and 2, illustrates this housing 9 arranged distinctly from the complementary shape 23 of the support 20:
- Figures 1 and 2 illustrate, according to a first variant, this housing 9 on a face of the tray 4 oriented differently from the face of the tray 4 comprising the protrusion 11, so that the first and second fixing means do not immobilize respectively the battery 1 and the hermetic casing according to the same degrees of freedom,
- there illustrates, according to a second variant, this housing 9 on a face of the tray 4 oriented in the same way as the face of the tray 4 comprising the protrusion 11, but this housing 9 is distant from the complementary shape 23 of the support 20 so that it does not fit into the complementary shape 23, even if then the first and second fixing means respectively immobilize the battery 1 and the hermetic casing according to the same degrees of freedom.

There is a third embodiment variant according to the invention, and which differs from the second variant in that this housing 9 is a recess in the internal face of the wall 5, the protrusion 11 being produced by the external face of the wall 5 opposite this depression.

Thus the heel 8 of the battery 1 is embedded in the housing 9, housing 9 which via the thickness of the wall 5 forms the protuberance 11 which itself is fitted into the complementary shape 23 of the support 20.

The first fixing means 8, 9, 10 further comprises, for example, a plate 10 screwed onto the internal face of the wall 5 and resting on the heel 8 of the battery 1. It will be noted that as for the protuberance 11, the fastening system may comprise several heels 8 distributed over the periphery of the battery 1. It will also be noted that, in the case where only one degree of freedom of the battery 1 remains to be blocked, this plate 10 does not is not necessarily resting on heel 8, but more generally on battery 1.

The internal face of the wall 5 comprises for example a network of ribs 15 projecting towards the internal space 6, this network of ribs 15 forming for example a honeycomb network as illustrated in the .

As already mentioned, this fastening system finds an advantageous application in the automotive world, and applies most particularly to a vehicle comprising:
- support 20,
- battery 1,
- the hermetic casing 2, 3, 4, 5, 13 comprising the wall 5 delimiting the internal space 6 containing the battery 1, and forming the air gap 7 for thermal convection around the battery 1,
- the first fixing means 8, 9, 10 of the battery 1 in the hermetic casing 2, 3, 4, 5, 13,
- the second fixing means 11, 12, 14 of the hermetic casing 2, 3, 4, 5, 13 on the support 20,
this vehicle comprising a fastening system as previously described.

The air gap 7 is represented only in FIGS. 3 and 4, by dotted arrows, indicating a direction of air circulation. Are not shown in these figures, the fan 18 and the air inlet opening, nor the sleeve 19 and the air outlet opening, but from Figures 1 and 2 their presence and location is implicit.

Claims (10)

fastening system comprising:
- a battery (1),
- a hermetic casing (2, 3, 4, 5, 13) comprising a wall (5) delimiting an internal space (6) containing the battery (1), and forming a thermal convection air gap (7) around the battery (1),
- a first fixing means (8, 9, 10) of the battery (1) in the hermetic casing (2, 3, 4, 5, 13),
- a second fixing means (11, 12, 14) of the hermetic casing (2, 3, 4, 5, 13) on a support (20),
, characterized in that this second fixing means (11, 12, 14) comprises a protuberance (11) of the wall (5) forming a complementarity of shape (23) with the support (20). Fastening system according to Claim 1, characterized in that the protrusion (11) comprises stiffening ribs (12). Fastening system according to one of the preceding claims, characterized in that this protuberance (11) is an edge of the hermetic casing (2, 3, 4, 5, 13) forming a shoulder. Fixing system according to one of the preceding claims, the hermetic casing (2, 3, 4, 5, 13) comprising a bore (13), characterized in that the second fixing means (11, 12, 14) comprises a screw (14) passing through this bore (13) and capable of being engaged in the support (20). Fixing system according to one of the preceding claims, the first fixing means (8, 9, 10) comprising a heel (8) of the battery (1) and a housing (9) of the wall (5), this heel (8) of the battery (1) being embedded in this housing (9). Fastening system according to Claim 5, characterized in that this housing (9) is a depression in the internal face of the wall (5), the protuberance (11) being produced by the external face of the wall (5) -à-vis this depression. Fixing system according to one of Claims 5 and 6, characterized in that the first fixing means (8, 9, 10) comprises a plate (10) screwed onto the internal face of the wall (5) and resting on the heel (8) of the battery (1). Fastening system according to one of the preceding claims, characterized in that the internal face of the wall (5) comprises a network of ribs (15) projecting towards the internal space (6). Fastening system according to Claim 8, characterized in that the network of ribs (15) forms a honeycomb network. Vehicle including:
- a support (20),
- a battery (1),
- a hermetic casing (2, 3, 4, 5, 13) comprising a wall (5) delimiting an internal space (6) containing the battery (1), and forming a thermal convection air gap (7) around the battery (1),
- a first fixing means (8, 9, 10) of the battery (1) in the hermetic casing (2, 3, 4, 5, 13),
- a second fixing means (11, 12, 14) of the hermetic casing (2, 3, 4, 5, 13) on the support (20),
characterized in that it comprises a fastening system according to one of the preceding claims.