VENTILATION ARRANGEMENT FOR BATTERY HOUSING(S) AND ASSEMBLY METHOD

Abstract

The ventilation arrangement (1) includes an annular connector (2) covering an opening in a battery case, defining a venting channel (C2). Assembly is simple, with the option of mounting a cover or similar element with a sealing portion (30) on the axial end of a tubular body (20) of the connector. This body also has lateral openings (4) allowing the flow of a centrifugal radial flow (G) in case of overpressure in the case. The flow passes through a diaphragm assembly (5), covering each opening (4) and fixed to the tubular body (20), for example, by extending around the central axis of the body. The arrangement, which allows for pressure compensation, can be pre-assembled. In case of sudden overpressure, an axial gas flow can escape from the channel (C2) by forcing the cover open, without passing through a diaphragm (5). (See abstract figure: Figure 1)

Description

Title of the invention: VENTILATION ARRANGEMENT FOR BATTERY HOUSING(S) AND ASSEMBLY METHOD Technical field

[0001] The present disclosure relates to the field of battery systems, in particular battery ventilation equipment for compensating for pressure imbalances. The invention relates more particularly to a ventilation arrangement for mounting on the housing of a battery / power supply and a method for assembling such an arrangement. Technological background

[0002] Document DE 102019100085 A1 discloses ventilation systems having a cover mounted on a base fixedly attached to the battery housing. These systems have a membrane associated with a movable support, which lifts in response to a build-up of pressure inside the housing. Venting is carried out in two modes: one by default allowed by the permeability of the membrane, the other emergency which releases a large passage section for the escape of air. The build-up of pressure beyond a predetermined threshold (overpressure threshold) makes it possible to overcome the force of a helical spring which urges the membrane and its support towards a seating area of ​​the base.

[0003] With this type of safety, if the battery continues to operate in a defective state or corresponding to thermal runaway, massive ventilation can limit or prevent irreversible damage to the battery and possibly serious injuries, for example in the event of a fire. The assembly required in DE 102019100085 A1 is, however, quite complex.

[0004] Document DE 102017214754 A1 proposes a different assembly for obtaining a ventilation device which integrates a membrane on a movable valve with an axial rod. In certain circumstances, jets of liquid can impact the membrane with a risk of degradation of the latter, which can limit its useful life.

[0005] There is therefore a need for devices of simple design, robust, usable effectively for the ventilation of batteries. Summary

[0006] The present disclosure improves the situation.

[0007] For this purpose, there is provided a ventilation arrangement for a battery box (power supply box), in particular comprising one or more batteries, the arrangement comprising: - a connection element (including or forming a connector which may be optional- (fully made of one piece) capable of being mounted in an opening of the housing or of forming part of a wall element of the housing, the connecting element having a tubular body extending around a central axis and capable of delimiting an air evacuation channel which communicates with the interior of the housing (preferably by opening directly / axially inside the housing); - a sealing portion which extends transversely relative to the central axis, in order to seal the canal; - at least one membrane including an air-permeable membrane material and arranged to cover one or more lateral openings formed on the tubular body, each lateral opening allowing the passage of a radial gas flow through said membrane material to establish gas communication between the channel and the exterior of the housing, whereby the arrangement allows pressure compensation.

[0008] With such an arrangement, ventilation is achieved efficiently, possibly with a distribution of the gas flows around the circumference of the tubular body, for example over an openwork section at least 1 cm long formed in the tubular body. The design and sizing of the side openings may vary, which provides a gain in versatility. A wrap may be provided by rolling and fixing, possibly carried out in one operation.

[0009] In the event of sudden overpressure in the battery housing, an axial gas flow can escape from the channel, blowing off the closure / cover portion, typically without passing through a membrane (without filtration), given the peripheral arrangement of such a membrane. The wrapping of such a section can be enabled in various ways, possibly by a single part constituting the membrane, this part being for example welded or overmolded in edge regions along the side opening(s).

[0010] Each lateral opening may be delimited in a tubular section, for example with two adjacent lateral openings only separated by a bar arranged in the tubular section. More generally, the lateral distribution membrane(s) may correspond to a layer, continuous or discontinuous, making it possible to cover the entire passage(s) (lateral opening(s)) defined by the hollow tubular body. The assembly of the membrane portion(s) may be accomplished by depositing a layer (including the membrane material) by wrapping it around the tubular body and securing this layer to a surface of the body to act as a filter. Alternatively, membrane portions may be deposited and secured to filter the flow passing through the openings.

[0011] With these provisions, we combine the possibility of a simple assembly with the faculty of: - limit the risk of impact of high pressure jets on the membrane portions, given the peripheral distribution of these portions in relation to the channel, - and possibly to easily control the mobility of each membrane, which can deform radially outwards in the event of overpressure in the channel (which is at the pressure inside the housing).

[0012] The structure of the membrane allows air passage, for example due to the porous structure of the membrane material that covers the side opening(s). The membrane may be hydrophobic or oleophobic. The arrangement allows pressure compensation in both directions via the annular membrane assembly(s). In the event of sudden overpressure, the sealing part may possibly jump, separating from the tubular body. More generally, the tubular body may have a free, annular edge, which delimits a large opening, for example wider than any of the side openings, so that a removal of the sealing part from this large opening, by pushing from the inner side (discharge channel side) allows a massive gas escape.

[0013] The arrangement can allow two levels of degassing when the closure part is movable / removable in response to an overpressure exceeding a threshold for which ventilation by the membrane(s) no longer evacuates the gas quickly enough: - the first level of degassing which is sufficient when the overpressure in the battery box and in the channel remains below the aforementioned threshold (this is breathing via the rolled membrane or the membranes arranged on the periphery of the tubular body); - the second level of degassing which is achieved by removing / moving the cover, in order to discharge high pressure air (the cover pops off under a certain pressure exceeding the aforementioned threshold). It is therefore possible to obtain a ventilation unit / arrangement that meets different situations without necessarily having valves that complicate the assembly.

[0014] According to a feature, the tubular body extends, from the free edge, to an annular base or wall element (open to form an end of the channel opposite the free edge which is accessible from the inside of the housing) which preferably extends transversely with respect to the central axis. The wall element may have connection means or may be welded, so that axial retention of the connection element / connector against the housing is obtained. The retention is accompanied by a sealing contact, obtained directly or by means of an annular seal separate from the part constituting the connector.

[0015] According to one or more of the following particularities, the closure portion may: - include or be made in the form of a removable plate; - rest on an internal shoulder provided in the tubular body; - constitute a cover which is held axially on the inside of the tubular body, so as not to cover this body from the outside; - carry an annular seal, for example housed in a circumferential groove of the sealing portion; - have an annular seal for annular radial contact against the tubular body; - be mounted in a separable manner by pushing, so that the sealing part jumps when the overpressure of the gas present in the evacuation channel exceeds a threshold.

[0016] In embodiments, the tubular body projects axially from an annular base (arranged around a central hole) which extends transversely relative to the central axis, the tubular body forming an annular, preferably cylindrical, bearing surface on which a sealing element carried by a cover including or forming the closure part rests. Typically, the gas flow in case of slight internal suppression can reach the outside by passing into the channel without blowing the obturation part through a membrane assembly which covers each side opening by being fixed (preferably selectively fixed) on the tubular body.

[0017] The membrane(s) bypass the channel. The attachment is obtained for example by overmolding or welding (for example hot with plastic fusion) each membrane to the contours of the lateral openings. The membrane assembly can be attached to an external face or to an internal face of the tubular body. Each side opening may be formed in a first portion of the tubular body which is distinct and axially spaced from the annular bearing surface.

[0018] Advantageously, it is permitted if necessary to add a central guide on the cover, to cooperate with a guide element carried by the connection element in a central zone via spacers (which join for example the first part from the inside). More broadly, a central component or a central structure can be provided in the channel without interfering with the operation of each membrane, therefore without hindering pressure balancing, unlike a configuration with a transverse membrane which extends internally in the channel while being crossed by the central axis. It is also permitted to carry out an assembly without any interference between the sealing zones and the clearance zone (essentially towards the outside of the channel in cases of overpressure) of the membrane portions associated with the respective lateral openings of the tubular body.

[0019] In options, the cover including the sealing portion is wider than the tubular body and has an external skirt, for example provided to allow the cover to be fixed and / or to protect the membrane(s) from high-pressure water jets coming from outside the housing.

[0020] In embodiments, the tubular body has one or more of the following features: - each lateral opening extends closer (radially) to the central axis than a joint carried by a wall element forming a base or plinth of the arrangement. - each lateral opening is formed in a first part of the tubular body, the first part being extended by a second part provided with: a region for fixing a cover; and / or the annular surface. - each lateral opening is further from the central axis than an annular junction zone or contact between the tubular body and the obturation portion blocking the channel. - one or more side openings consist of at least two side openings. - the side openings are each closed (and thus fully / entirely covered) by membrane material. - the lateral openings are selectively distributed in a circumferential region of the tubular body which extends axially between the annular bearing surface and the annular base. - the annular body has a free edge distal to the housing, opposite the base, with an opening delimited by the free edge. - the opening delimited by the free edge is closed by the cover. - the cover includes an annular skirt connected to the sealing portion and which extends longitudinally in overlap, at least along a second part of the annular body which extends to the free edge; and - is mounted on the connection element by fitting in a direction of approach towards the base.

[0021] According to a particular feature, the arrangement comprises elastically deformable sealing means configured: - to achieve the connection of the closure part to the rest of the arrangement, the sealing means achieving a sealed annular contact, preferably radial, between a part including the closure part and a part including the base. Alternatively or in addition, the sealing means allow the disconnection of the closure part with a withdrawal and / or a separation of the closure part, by elastic deformation of the sealing means when the overpressure on the side of the air present in the air discharge channel exceeds a threshold.

[0022] In preferred options, the at least one membrane (or at least a portion central membrane coinciding with a central zone of a lateral opening) is radially movable, being deformed in a centrifugal direction in the event of exceeding an overpressure limit in the air discharge channel. More generally, the membrane assembly(s) may include a band in a circumferential direction on the tubular body delimiting the discharge channel. When a membrane or set of several membranes has a band format, such a band may be continuous having a circumferential extension covering an angular sector of at least 80° around the central axis, and preferably covering at least half a circumference of the tubular body.

[0023] A permeable layer, formed by this type of membrane(s), can thus be superimposed on the lateral face of the tubular body, for example by covering at least 20 or 30% of the lateral face of the tubular body. In certain options, most or all of the circumference of the tubular body can be covered by at least one membrane, preferably without a membrane extending to the free edge (for example to leave a first part of the tubular body uncovered, without interfering with the installation of a cover / sealing part).

[0024] When the arrangement has a strip to constitute all or part of the membrane assembly(s), such a strip has a substantially constant extension along the direction of the central axis, which may represent for example between 20 and 80% of the total length of the tubular body. In a multi-band option (with the membrane assembly consisting of several bands), a partial overlap / superposition of the bands or a non-overlapping configuration may be provided. The distribution of bands is carried out along a circumference of the tubular body. Each of the bands may each have a circumferential extension covering an angular sector of at least 40° around the central axis. Optionally, each of the bands covers at least a quarter of the circumference of the tubular body.

[0025] In one option, in at least one membrane attached to the tubular body, the membrane material has a substantially rectangular sheet format, with two short sides extending along the central axis (these two short sides being substantially parallel). Optionally, the two long sides are also parallel. The two long sides are, for example, either curved or substantially straight. Substantially flat attachment zones may be provided on regions of the external lateral face of the tubular body to allow at least one portion of membrane to extend in a plane in an undeformed configuration. In variants, the membrane(s) are attached from the inside of the tubular body, where appropriate by being attached to an area delimited between reliefs or shoulder(s) provided internally on the tubular body. Whether the adopted format is rectangular or not, at least one membrane has, for example: - an elongated format following a circumferential direction in the arrangement; - and / or a circumferential extension covering an angular sector of at least 120° around the central axis.

[0026] According to a particular feature, the connection element can be made from a single piece (of rigid material) and allows, by means of two respective annular sealing elements: - to produce, by means of a first annular sealing element which is carried by the connection element (this first element projecting axially in a first direction), an annular contact with the battery housing; - to produce, by means of a second annular sealing element, a radial annular contact with a skirt belonging to a cover part including the closure part. Optionally, the cover part is adapted to delimit, by a bottom, the air evacuation channel, on the one hand, and to extract and detach itself from the connection element, following a movement in a second direction opposite to the first direction, on the other hand.

[0027] The first seal may be housed in an internal groove of a base of the connection element which opens axially opposite the closure part, in order to provide an annular seal with the housing. The second seal may be housed in a circumferential external groove, formed in the closure part, to obtain an annular seal with a cover which remains secured to the tubular body when a gas flow passes through the membrane, at least as long as an overpressure threshold internal to the housing has not been exceeded.

[0028] The arrangement may be assembled by achieving sealing between the connecting element and the cover before mounting to cover a battery housing opening. A pre-assembled design, without mobility of the locked cover, allows the arrangement to be able to effectively seal the opening, preferably in a gas-tight manner, in an environment subject to vibrations. This is particularly the case when the battery housing is mounted in a motor vehicle, for example an automobile or other rolling machine.

[0029] The features set out in the following paragraphs may, optionally, be implemented, independently of one another or in combination with one another: - the connecting element has an edge which is annular in shape and / or distributed in at least two sections spaced apart from each other, making it possible to create a stop preventing the cover from sinking down to the section where the openings are located lateral. - the sealing part is kept axially distant from the membrane assembly. - the sealing part is inserted into a hollow space of the tubular body. - the hollow tubular portion has an internal, annular swelling or bulge in the area of ​​contact with the cover.

[0030] According to another aspect, there is provided a method of assembling the ventilation unit / arrangement presented above (ventilation unit for a battery housing, in particular of a housing comprising one or more batteries), using a membrane capable of allowing pressure compensation and a connection element typically allowing a connection to close access to an opening of the housing and allowing a disconnection of a closing part which blocks the end of an air discharge channel delimited by the connection element, the method comprising the steps consisting essentially of: - covering one or more lateral openings provided on a tubular body of the connecting element, with the membrane, so that the membrane allows the passage of a radial gas flow through a membrane material to establish gas communication between the channel and the exterior of the connecting element; - secure the closure part to the connection element, by means of a watertight fixing, so that it extends transversely relative to a central axis of the tubular body; whereby a pre-assembled ventilation unit is obtained, suitable for covering a connection port or opening of the battery housing from the outside of the housing, the channel being able, opposite the closing part, to communicate directly with the inside of the housing in the connected state of the ventilation unit on the housing.

[0031] The useful surface area of ​​the membrane can be reduced and / or optimized as required, by dimensioning the side openings. Assembly is rapid to obtain a pre-assembled ventilation unit that does not yet cover the opening of the battery box. The arrangement can therefore be transported, packaged and delivered in a robust manner, without risk of detachment of the cover, and makes it possible to limit the number of steps for installing the arrangement on the battery box. In options, a simple screwing or a bayonet connection can make it possible to obtain sealing thanks to the seal of the base / wall element P2, while the cover 3 will remain in its sealed closure configuration, fitted onto the connection element 2. Brief description of the drawings

[0032] Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the attached drawings, in which: [Fig.l] shows, in sectional view, a ventilation unit capable of being mounted directly on a wall of a battery box, in order to close an opening in this wall. [Fig.2] illustrates, in perspective view, the connector of the unit shown in [Fig.l], before a cover is fitted, and after the attachment of an outer air-permeable layer, including at least one membrane, to cover the side openings of the connector. [Fig. 3] is an exploded perspective view of the ventilation unit of [Fig. 1]. [Fig. 4] illustrates, in sectional detail, an alternative embodiment of a base portion of a ventilation unit. [Fig.5] is a perspective view from below illustrating, before the membrane layer(s) are laid, an option for producing a ventilation unit provided with a cover cooperating with a portion of the external surface of the connection element or connector. [Fig.6] illustrates an example of mounting the ventilation unit, for example with an insertion part as in the case of [Fig.4], on an external face of a wall of the battery box. Description of the embodiments

[0033] Several examples of non-limiting embodiments are set out below in detail. In the various figures, identical references indicate identical or similar elements. The height direction corresponds to that of the Z axis shown in [Fig.l]. The Y axis corresponds to an example of a radial direction (which may also correspond to a thickness dimension), perpendicular to the central axis X of a tubular body 20 provided in the ventilation arrangement 1 which is detailed in the following.

[0034] With reference to Figures 1, 2, 5 and 7, there is shown a ventilation unit or arrangement 1 that can be delivered as a pre-assembled unit, ready to close an opening O of a battery case (see [Fig.6]) by being mounted typically on the side of an external face of a shell or plate of the case P. In the following, this pre-assembled unit is called ventilation arrangement 1. In preferred options, the arrangement 1 has a support part including or consisting of a connection element 2, possibly provided with fixing means MF1 or a wall element P2 or plate. More generally, the arrangement 1 connects to a wall P of the battery case, so as to cover the opening O. In the case of [Fig.4], the fixing means MF1 are for example formed as insertion / retaining tabs for holding in position on the battery housing. The fixing means MF1 may be provided in the base of the element of connection 2, extending from an inner part which is optionally insertable inside the battery housing. Element 2 may consist essentially of a rigid connector, optionally provided with seal(s) J1, J2 attached to this connector.

[0035] The fixing means MF1 may be included in a part constituting the annular body 20 of the connection element 2. This element 2 supports at least one membrane making it possible to filter the incoming and outgoing flows of the housing via a channel C2 delimited by this element 2 and described later. More generally, the connection element 2 may have a body 20 which is rigid, perforated to form at least one lateral opening 4, typically being injection molded in a single piece. The fixing means MF1 may be provided in this part, in a connection part corresponding to a connector base. Connection element

[0036] With reference to Figures 1 and 6, the connection element 2 has a generally annular-shaped portion, which may correspond to an external projection relative to the housing. The connection element 2 has a tubular body 20 open at its two axial ends (with respective openings 02 and 03, as visible in Figures 2 and 3) and further provided with one or more lateral openings 4. Such lateral openings 4 are distinct / spaced (here axially spaced and separated) from the openings 02 and 03 forming the ends of the channel C2. When the tubular body 20 is straight (not bent or inclined), these two openings 02, 03 are axial openings which may share the same axis of symmetry, coinciding with the central axis X of the tubular body 20.In all that follows, the central axis X corresponds to an axis of the body 20 around which several lateral openings 4 are formed or at least one lateral opening 4 of a section (openwork section) of the tubular body 20.

[0037] The connection element 2 carries one or more membranes 5 in order to cover each lateral opening 4, which allows a gas filtration effect. This prevents impurities (solid particles or undesirable components) from entering the housing. The fixing can be carried out from the inside and / or from the outside of the tubular body 20, for example by using fixing regions RFI, RF2 located in a periphery of the lateral opening 4 to be covered. In [Fig. 3], a first fixing region RFI, for the membrane fixing, is illustrated which is distal from the free edge 21 and parallel to a second fixing region RF2 which is comparatively closer / proximal to the free edge 21.

[0038] These two fixing regions RFI and RF2 are distributed axially on either side of at least one of the lateral openings. A continuous annular fixing (gas-tight) of a membrane 5 may be preferred, in these two RFI regions. This allows a sealed separation of the channel C2 from the outside, by this membrane 5 when it is wound around the channel C2 with a longitudinal sealed junction (gas-tight) which can be made in a suitable manner, for example at two edges 5a, 5b secured against the same bar 6 of the body 20 which separates two lateral openings 4 adjacent to each other. In options, an overlap of the ends or short edges of a membrane 5 thus wound can be provided, in order to avoid gas escape between the two fixing regions RFI and RF2. The membrane 5 is in a single piece and can have a strip format.

[0039] In variants using several membranes 5, optionally each in a strip format, the fixing can be carried out on discontinuous fixing regions along the circumference of the tubular body 20. In this case, each membrane 5 can selectively cover one or two lateral openings while having an elongated format, for example making it possible to cover a sector of more than 40° in the circumference of the tubular body 20. Regardless of the format and number of membranes 5, provision may be made to have a fixedly attached assembly of membrane(s), by a margin zone wider than the opening(s) 4 to be covered, on a first part 2a of the tubular body, at a distance from the blocked end of the tubular body 20.

[0040] In order for all of the gas to be filtered by the membrane(s) 5 (under normal operating conditions), the connection element 2 is: - plugged at its distal axial end of the housing; - and connected in a sealed manner to the plate P of the housing delimiting the opening O. This element 2 can optionally allow a seal J1 to be tightened against the battery housing. As shown in Figures 2 and 4, the body 20 corresponds to a ring or similar tubular member, which extends longitudinally around a central axis X, up to a free edge 21 axially distal to the opening O.

[0041] As illustrated in Figures 1 and 4, it is understood that the base may have an annular radial portion P2 which includes or forms the bottom of a groove G1 oriented towards the housing, making it possible to receive an annular seal J1. This seal J1 has a height typically greater than the depth of the groove G1. More generally, the seal J1 may project downwards (here towards the housing) thus having a surface which extends out of the groove G1 and capable of bearing axially against the battery housing. The annular faces delimiting the groove G1 may each have projecting ribs or reliefs for retaining the annular seal J1. These reliefs or ribs, distributed in a spaced manner along the circumferential direction, project radially towards the inside of the groove G1.

[0042] Bayonet connection means, with radially outwardly projecting tabs, may constitute all or part of these fixing means MF1. In the option of [Fig.4] for example, the tabs cooperate with a border of the opening O of the housing having several specific radial slots distributed in the same way as these tabs. A rotational movement can make it possible to lock the position of the connection element 2, with an alignment relative to a center of the opening O. In variants, the connection is made with a screw or with any type of rotation to lock the connection element 2 axially. A fixing with deformation of a joint with an anchoring function can also be carried out, if necessary without rotation. In the non-limiting case of [Fig. 4], the connection element 2 extends from the free edge 21 to an annular opposite edge which can penetrate into the housing, this opposite edge forming part of an insertion end T which projects axially relative to the part which carries the seal JL

[0043] The bayonet connection means or, more generally, fixing means MF1, may be arranged radially closer to the central axis X than is the groove G1. Alternatively, for example for an option with a peripheral weld or retainer, the fixing is carried out in an outer margin of the wall element P2. In all cases, the connection element 2 includes a tubular body 20 formed as a projection projecting axially from the radial portion constituting the wall element P2. Such a projection may axially extend the base so that the base and the projection delimit an annular (common) internal face of the connection element 2. This internal face delimits an evacuation channel C2 which allows gas to escape from the housing, knowing that gas exhaust openings O3, 4 are provided in the connection element 2.

[0044] With reference to [Fig.2], the height H20 of the tubular body 20 may be less than a diameter of the channel C2. This height H20, for example greater than or equal to 22 mm, makes it possible to produce lateral openings 4 with a height greater than 10 millimeters (term height measured along the direction of the central axis X). The width of the tubular body 20 also makes it possible to have several lateral openings 4 whose circumferential extension may reach or exceed the size of half a diameter of the channel C2. In this way, the passage section for the outgoing gas flow G via the lateral openings 4 may be comparable, possibly equal to the passage section of the channel C2, in order to avoid inducing pressure differences.

[0045] The height h5 of the membrane assembly 5 may be substantially constant, for example exceeding the height of the side openings 4, with possibly an excess height not exceeding 10 or 12 mm in certain options. The membrane 5 may be delimited between two elongated straight edges 51, 52, which are substantially parallel. A rectangular membrane format may be adopted. The membrane 5 may extend in height over the first part 2a of the tubular body 20 which joins the base / wall element P2. The extension or height h5, along the direction of the central axis X, can represent between 20 and 80% of the total length, here called height H20 with reference to [Fig.2], of the tubular body 20.

[0046] In arrangement 1, the two seals J1, J2 may be separated and arranged axially on either side of the lateral openings 4. The first seal J1 is housed in an internal groove G1 of the base or wall element P2, further inside than the fixing region RF1. This groove G1 opens axially opposite the closure portion 30 and makes it possible to make an annular sealing contact with the housing. An edge of the opening O may constitute an annular seat on which the seal J1 rests (on an external face of the edge), while the end T may engage with this edge. The second seal J2 may be carried by the connection element 2 or by a cover 3 including the closure portion 30. This second seal J2 may be arranged axially higher / closer to the free edge 21 than the fixing region RF2. The seal J2 is for example: - either housed in a circumferential groove of the connection element 2 when it is carried by the latter (external circumferential groove for example if the cover 3 has an external skirt 302), - either carried by an annular groove G delimited in the cover 3 with possibly a protective end which covers this seal J2 in an axially intermediate zone between the lateral opening(s) 4 and the extension zone of the seal J2 (which protects the seal). Fixing a shutter part

[0047] The connection element 2 is configured to be plugged at its end projecting outside the housing. When it has an annular free edge 21, a removable closure part 30 is attached to the connection element 2 to close the axial opening 03, by a stable fixing under normal operating conditions. The closure part 30 thus remains in place even in the event of slight overpressure on the side of the channel C2, taking into account for example the friction contact exerted on the entire circumference of the tubular body 20. In the case of [Fig.l], the contact zone is produced via the seal J2, on a second part 2b of the tubular body 20 which is distinct and axially spaced from the contact zone between the cover 3, 3' or closure part 30 and the tubular body 20. In the illustrated examples, the tubular body 20 includes an annular bearing surface 8, at which the closure part 30 or cover 3 rests / fixes in a gas-tight manner. This bearing surface 8 may be selectively provided in the second part 2b, for example near the free edge 21 or in any case: closer to the free edge 21 than to the other end through which the channel C2 opens internally.

[0048] The internal face of the tubular body 20 may constitute a region for fixing a cover 3, as visible in the non-limiting option of [Fig.l]. Alternatively, it is the external face of this body 20 on which the cover 3' is fixed, as illustrated for example in [Fig.5]. With reference to [Fig.l], an internal shoulder E2 of the tubular body 20 is optionally provided, allowing the seal J2 carried by the cover 3 to come into contact with the body 20 in a region forming a narrowing of the passage section of the tubular body 20. As shown in [Fig.l] and in the exploded view of [Fig.3], the cover 3 may include a groove G for housing the seal J2. This groove G is a circumferential annular groove provided on a skirt 32 of the cover which axially extends a closing portion 30 of the cover 3. In variants, such a seal J2 is housed in a groove of the body 20 or in an internal groove of the cover 3.

[0049] With reference to [Fig.l], the cover 3 may have a central cavity C3 opening axially into the air evacuation channel. This arrangement is also applicable to cases of cover 3' having an external skirt 302 parallel to the internal skirt 32. The cavity C3 may be surrounded by a portion with a groove adapted to house the annular seal J2 carried by the cover 3. Apart from the seal J2, the cover 3 may be made from a single piece, which is typically molded from plastic material. More generally, the cover 3 has a main closure part 30 which may correspond to a bottom part, from which extends a tubular side wall, forming a skirt 32, 302 of the cover 3.

[0050] As visible in [Fig.l], a skirt 32 of the cover 3 may have an inner circumference which varies for a flaring effect, possibly by having an internal shoulder. Optionally, the skirt 32 comprises a narrowing due to the presence of the groove G. An annular end edge of the cover 3 may be inserted before the seal to allow a first centering of the skirt 32, without friction of the seal J2, when the cover 3 begins to axially cover the channel C2. Then the cover 3 is completely fitted to obtain the sealing contact C1.

[0051] Regardless of whether the cover 3 is mounted in advance on the connection element 2 or not, it may be provided that the sealing contact obtained by the seal J2 is obtained with friction which opposes accidental removal of the closure part 30.

[0052] In the non-limiting example of Figures 2 and 6, it is understood that the seal J1 secured to the base is a first seal J1 adapted to rest on an annular seat zone provided on the housing, around the opening O, typically without penetrating internally into the housing. This seal J1 may be an annular seal, for example made of elastomeric material, coming axially into contact with the housing, on an external face of the latter. Here one or more seals are illustrated which are added or integrated into the connection element 2, in order to produce in particular a sealed annular contact in a peripheral zone situated around a circumference of the opening O, for a gas-tight contact here. For example, the seal J1 carried by the base B of the body 20 is axially biased against the plate P of the battery housing including the opening O. Of course, a seal could also be mounted directly on a plate P of the housing, for example on a suitable groove area, at which an axial and / or radial clamping action can be exerted on the seal by the base B, for a locked configuration using the fixing means MF1.

[0053] In the arrangement 1 which forms an evacuation duct / channel C2, here by the connection element 2, it is possible to integrate the second seal J2 in an area separated from the circulation of gases in the channel C2, either using an end return / rim provided at one end of the cover 3 as an extension of the inner skirt 32, or by arranging this seal 2 outside the inner volume delimited by the tubular body 20.

[0054] The air evacuation channel C2 delimited by the connection element 2 communicates via the opening 02 with the interior of the housing. The housing may itself contain battery modules, so that the plate of the housing P on which the arrangement 1 is mounted is not in direct contact with liquid or fluid substance involved in electrochemical reactions. The air evacuation channel C2 may also open axially to the outside, through another opening 03 (clearly visible in [Fig. 2] in particular), when a free edge 21 of the tubular body 20 constitutes the termination of the connection element 2. Examples of operation of the membrane assembly(s)

[0055] With reference to [Fig. 2], the arrangement 1 can cover all of the lateral openings 4 from the outside. Thus, as soon as an internal pressure increases in the zone Z1, on the inside of the housing, there is an overpressure in the channel C2 compared to the outer zone Z2 which extends around the membrane assembly 5. With reference to [Fig. 1], a pressure compensation is then exerted in such a case via the openings 4 and the membrane 5, with the outgoing gas flow G flowing radially through the membrane material. The gas flow leaving or entering the channel C2, via the membrane 5, can flow radially by passing under edges 25 delimiting the openings 4 which are distributed in the same annular line. The edges 25 can be coplanar and / or arranged in an intermediate zone of the body 20 which extends at a distance of at least one third of the length (1 / 3 of H20) from the free edge 21 and at least one third of the length (1 / 3 of H20) from the opposite / inner outlet of the channel C2.

[0056] Each lateral opening 4 may be delimited in a tubular section of the body 20, possibly cylindrical, for example with two adjacent lateral openings 4 only separated by a bar 6 arranged in the tubular section. A structure with at least two spaced bars may make it possible to delimit the lateral openings 4, in the first part 2a which constitutes the tubular section. When four lateral openings 4 are provided, four bars 6 can thus be provided, for example by being distributed in two pairs each having two diametrically opposed bars. A planar arrangement of the openings 4 can optionally be adopted, for example to attach different membranes 5 on the first part 2a with a substantially planar configuration of each membrane.

[0057] In the illustrated examples, the tubular body 20 has a symmetry of revolution, with a circular cross-section. This allows the outgoing or incoming gas flows to be distributed homogeneously. Alternatively, other sections (for example oval, oblong, rectangular) may be used and / or the free edge 21 may be beveled. In certain options, the connection element 2 may be plugged at least partially by a portion made in one piece with the tubular body 20, depending on whether or not an emergency plug associated with the channel C2 is required.

[0058] The arrangement 1 may include a closure part 30 which cannot withdraw in response to a depression in the housing, therefore a depression on the side of the inner zone Z1, insofar as an axial thrust force from the outside towards the inside (see arrow DI in [Fig.6]) cannot cause an axial displacement of this part 30 which remains blocked by a stop or shoulder E2 provided in the connection element 2. Conversely, in the event of excess pressure in the channel C2 / zone Z1, the large surface of the closure part 30 is entirely subjected to the excess pressure in the channel and the closure part 30 can jump away from the opening O2. The sensitivity threshold for this withdrawal of the closure part 30 or cover 3, 3' may depend on the inner surface of the closure part and a friction level of the seal J2 for the maintaining the cover-tubular body contact watertight.

[0059] In the event of thermal runaway and / or abnormal conditions leading to overpressure in the channel C2, it is understood that the pressure is sufficient to move the closure part, the flow filtered by the membrane 5 not being sufficient to compensate for the imbalance. The lateral arrangement of the membrane 5 makes it possible to obtain good reactivity of the cover 3, 3', which can jump quickly to prevent a situation likely to lead to thermal runaway.

[0060] The opening O is then immediately made accessible without filtration, by removing the cover 3 which disengages from the socket constituting the connection element 2, as soon as the pressure on the inner side (side of the internal volume of the battery case) exceeds a threshold linked to the friction of the sealing contact (which can be linked to the deformation / compressibility of the seal J2). A significant pressure corresponds to a displacement force exerted on the transverse closure portion 30. In variants, not illustrated, a clip or lock system capable of deforming to unlock the position of the cover 3, 3' can also be adopted. A lock system can facilitate the replacement in position of the cover 3, 3' with a high level of reliability, with typically less pushing effort to reach the position of closing the opening 03.

[0061] The present disclosure is not limited to the embodiments described above, only by way of example, but it encompasses all the variants that may be envisaged by those skilled in the art within the framework of the protection sought.

[0062] For example, two separate connectors may be provided on the battery housing, with one forming the connection element 2 openwork only laterally and carrying a membrane assembly(s) 5, and the other tubular one carrying the emergency cover 3, 3'. In this case, it is understood that the plug or sealing part 30 (to plug the channel C2) corresponds to the bottom of the connection element 2, which carries the membrane(s) 5 in a peripheral zone of the channel C2.

[0063] Furthermore, the expression battery case must be understood in a general sense, the case being able to contain one or more groups of accumulators capable of providing energy in electrical form or energy usable in any form for conversion into electrical energy.

[0064] The housing wall P including the opening O can have any orientation. Although the non-limiting example of [Fig. 6] corresponds to an orientation of this plate P in a generally horizontal plane to have a vertical tubular body 20 (the axis X is here vertical) with, where appropriate, a cover 3 axially surmounting (from above) the connection element 2, other arrangements are permitted, in particular with a ventilation unit mounted laterally on the battery housing.

[0065] Finally, although in the figures a distribution of several lateral openings 4 has been shown with the membrane assembly(s) which goes entirely around the tubular body 20, there are also provided options of realization with a single window or lateral opening 4, without the associated membrane 5 extending over the entire circumference. In such a case, it may be preferable to have a membrane 5 having a circumferential extension covering an angular sector of at least 120° around the central axis X, which can make it possible to optimize the passage surface for the gas flow without excessively increasing the longitudinal extension of the connection element 2.

Claims

Claims

1. Ventilation arrangement (1) for a battery housing, in particular comprising one or more batteries, the arrangement (1) comprising: - a connection element (2) capable of being mounted in an opening (0) of the housing or of forming part of a wall element of the housing, the connection element (2) having a tubular body (20) extending around a central axis (X) and capable of delimiting an air discharge channel (C2) in communication with the interior of the housing, - a closure portion (30) which extends transversely with respect to the central axis (X), in order to close the channel (C2);- at least one membrane (5) including an air-permeable membrane material and arranged to cover one or more lateral openings (4) formed on the tubular body (20), each lateral opening (4) allowing the passage of a radial gas flow through said membrane material to establish gas communication between the channel (C2) and the exterior of the housing, whereby the arrangement (1) allows pressure compensation.;

2. Arrangement according to claim 1, in which the tubular body (20) projects axially from an annular base (P2) which preferably extends transversely with respect to the central axis (X), the tubular body (20) forming an annular bearing surface (8), preferably cylindrical, on which a sealing element (J2) carried by a cover (3) including the closure portion (30) rests, each lateral opening (4) being formed in a first part (2a) of the tubular body which is distinct and axially spaced from the annular bearing surface (8).

3. Arrangement according to claim 2, wherein the one or more lateral openings (4) consist of at least two lateral openings which are: - each closed by membrane material; and - selectively distributed in a circumferential region of the tubular body (20) which extends axially between the annular bearing surface (8) and the annular base (P2).

4. Arrangement according to claim 2 or 3, in which the annular body (20) has a free edge (21) distal to the housing (B), opposite the base (P2), an opening (02) delimited by the free edge (21) being closed by the cover (3) which: - includes an annular skirt (32; 302) connected to the closure portion (30) and which extends longitudinally in overlapping, at least along a second part (2b) of the annular body (20) which extends to the free edge (21); and - is mounted on the connection element (2) by fitting in a direction of approach towards the base (B).

5. Arrangement according to any one of the preceding claims, comprising elastically deformable sealing means (J2) configured: - to effect the connection of the closure part (30) to the rest of the arrangement, the sealing means (J2) effecting a sealed annular contact (C1), preferably radial, between a part including the closure part (30) and a part including said base (B); and - to allow the disconnection of the closure part (30) with a withdrawal and / or a separation of the closure part (30), by elastically deforming the sealing means (J2) when the overpressure on the side of the air present in the air discharge channel (C2) exceeds a threshold.

6. Arrangement according to any one of the preceding claims, in which the at least one membrane (5) has a radially movable portion, being deformed in a centrifugal direction in the event of exceeding an overpressure limit in the air discharge channel (C2).

7. Arrangement according to any one of the preceding claims, wherein the at least one membrane (5) has a continuous strip format having a circumferential extension covering an angular sector of at least 80° around the central axis (X), and preferably covering at least half a circumference of the tubular body (20).

8. Arrangement according to claim 7, in which the strip constituting the membrane (5) has a substantially constant extension in the direction of the central axis (X), which represents between 20 and 80% of the total length (H20) of the tubular body (20).

9. Arrangement according to any one of claims 1 to 6, wherein the at least one membrane (5) consists of several strips each having a circumferential extension covering an angular sector of at least 40° around the central axis (X).

10. Arrangement according to any one of claims 1 to 9, wherein the connecting element (2) is made in one piece and allows, by means of two respective annular sealing elements: - to produce, by a first annular sealing element (Jl) which is carried by the connection element (2) projecting axially in a first direction, an annular contact with the battery case; - to produce, by a second annular sealing element (J2), a radial annular contact with a skirt (32; 302) belonging to a part forming a cover including the closure part, and in which said part forming a cover is adapted to: - delimit, by a bottom, the air evacuation channel (C2); - extract and detach from the connection element, following a movement in a second direction opposite to the first direction.

11. Method for assembling a ventilation unit for a battery case, in particular a case comprising one or more batteries, using a membrane (5) capable of allowing pressure compensation and a connection element (2) capable of allowing disconnection of a closure part (30) which blocks the end of an air discharge channel (C2) delimited by the connection element, the method comprising the steps essentially consisting of: - covering one or more lateral openings provided on a tubular body (20) of the connection element (2), with the membrane (5), so that the membrane (5) allows the passage of a radial gas flow through a membrane material to establish a gas communication between the channel (C2) and the exterior of the connection element (2);- securing to the connection element (2), by a sealed fixing, the closure portion (30) so that it extends transversely relative to a central axis (X) of the tubular body; whereby a pre-assembled ventilation unit is obtained, suitable for covering from the outside of the housing a connection port or opening (O) of the battery housing, the channel (C2) being able, opposite the closing part (30), to communicate directly with the inside of the housing (B) in the connected state of the ventilation unit on the housing.

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