阅读说明：本技术 脱气单元和电子器件壳体、尤其是电池壳体 (Degassing unit and electronics housing, in particular battery housing ) 是由 J·科西克基 R·兹比拉尔 S·沃佩尔 M·齐勒 F·朗古特 于 2021-05-26 设计创作，主要内容包括：本发明涉及一种用于电子器件壳体的脱气单元,该脱气单元具有能够流体密封地与电子器件壳体的压力平衡开口的边缘连接的基体,该基体具有至少一个气体穿透开口,该气体穿透开口由半渗透的膜片遮盖。膜片允许气态介质从周围环境穿透到电子器件壳体中并且反之亦然,但是阻止液态介质和/或固体的穿透。此外,脱气单元在基体的内侧上具有膜片支撑装置,该膜片支撑装置至少部分地搭接气体穿透开口并且以距半渗透的膜片的第一间距存在。具有多个栅格开口的分离栅格以距半渗透的膜片的、大于第一间距的第二间距布置在基体的内侧上,所述分离栅格完全搭接气体穿透开口。此外,公开了一种具有根据本发明的脱气单元的电子器件壳体。(The invention relates to a degassing unit for an electronics housing, having a base body which can be connected in a fluid-tight manner to an edge of a pressure compensation opening of the electronics housing, the base body having at least one gas passage opening which is covered by a semi-permeable membrane. The membrane allows the penetration of gaseous media from the surroundings into the electronics housing and vice versa, but prevents the penetration of liquid media and/or solids. The degassing unit furthermore has a membrane support device on the inner side of the base body, which at least partially overlaps the gas passage opening and is present at a first distance from the semipermeable membrane. A separation grid with a plurality of grid openings is arranged on the inner side of the base body at a second distance from the semipermeable membrane which is greater than the first distance, said separation grid completely overlapping the gas passage openings. Furthermore, an electronics housing with a degassing unit according to the invention is disclosed.)

1. A degassing unit (10) for an electronics housing, in particular for a battery, in particular for a traction battery of a motor vehicle,

the degassing unit has a base body (1) which can be connected in a fluid-tight manner to the edge of the pressure compensation opening of the electronics housing, the base body having at least one gas passage opening (15) which is covered by a semi-permeable membrane (6) which enables the passage of a gaseous medium from the surroundings into the electronics housing and vice versa, but prevents the passage of liquid media and/or solids,

and having a membrane support device (2) which is arranged on the inner side (17) of the base body (1) and at least partially overlaps the gas passage openings (15) and is present at a first distance from the semi-permeable membrane (6),

-wherein the base body (1) has at least one fixing means active area (11) provided for fixing the degassing unit (10) with the electronics housing,

characterized in that on the inner side (17) of the base body (1) a separation grid (8) having a plurality of grid openings (81) is arranged at a second distance from the semi-permeable membrane (6) which is greater than the first distance, wherein the separation grid (8) completely overlaps the gas passage openings (15), wherein the area spanned by the separation grid (8) is greater than the cross section of the gas passage openings (15).

2. The degassing unit (10) according to claim 1, wherein the membrane support device (2) is configured to be fluid-permeable, preferably configured as a grid section with a plurality of grid openings (24).

3. Degassing unit (10) according to claim 1 or 2, wherein the separation grid (8) is particle-tightly connected to the substrate (1).

4. The degassing unit (10) according to any one of claims 1 to 3, wherein the dimension of the grid openings (81) of the separation grid (8) in at least one direction of extension is less than 2.0 mm, preferably less than 1.2 mm, more preferably less than 0.9 mm.

5. The degassing unit (10) according to any one of claims 1 to 4, wherein the membrane (6) is present on an inner side (17) of the base body (1) and is at least partially engaged from behind by a support means (2).

6. The degassing unit (10) according to any one of claims 1 to 5, wherein the separation grid (8) bulges pot-like in the direction pointing inwards in the assembled state.

7. The degassing unit (10) according to any one of claims 1 to 5, wherein the separation grid (8) is substantially flat.

8. The degassing unit (10) according to any one of claims 1 to 7, wherein the degassing unit (10) has at least one spacer (12) which holds the separation grid (8) in a second spacing from the membrane (6) and which is configured to protrude either axially inwards from the base body (1) or axially outwards from the separation grid (8).

9. The degassing unit (10) according to any one of claims 2 to 8, wherein the dimensions of the grid openings (24) of the membrane support means (2) are larger than the dimensions of the grid openings (81) of the separation grid (8).

10. The degassing unit (10) according to any one of claims 1 to 9, wherein the separation grid (8) and the membrane support means (2) are configured independently of each other.

11. The degassing unit (10) according to any one of claims 1 to 9, wherein the separation grid (8) and the membrane support device (2) are constructed in one piece.

12. The degassing unit (10) according to claim 11, wherein the membrane support device (2), in particular a grid section of the membrane support device (2), is configured as an axial support ridge (83) of the separation grid (8), wherein the support ridge (83) is preferably present centrally with respect to the gas passage opening (15).

13. The degassing unit (10) according to any one of claims 1 to 12, wherein the separation grid (8) carries a filter medium (9), preferably comprising a grid material, in particular a metal wire grid and/or a non-woven material, wherein preferably the filter medium (9) has or consists of a metal material.

14. The degassing unit (10) according to any one of claims 1 to 13, wherein the separation grid (8) is connected to the base body (1) in a non-detachable or detachable manner, in particular in a snap-fit manner with the base body (1).

15. The degassing unit (10) according to any one of claims 1 to 14, wherein the spacing between the separation grid (8) and the membrane support means (2) in the region of the centre of the gas penetration opening (15) is at least 0.2 mm, preferably at least 0.7 mm.

16. The degassing unit (10) according to any one of claims 1 to 15, wherein the fixing means active area (11) of the base body (1) comprises a hole, in particular a blind hole, which is open towards the inner side (17) and/or the outer side (18) of the base body (1).

17. The degassing unit (10) according to any one of the preceding claims, wherein the separation grid (8) is configured as a sheet-metal piece, in particular a stamped sheet-metal piece, wherein preferably the separation grid (8) has at least one through-insertion opening which is aligned with at least one blind hole of the base body (1).

18. The degassing unit (10) according to any one of the preceding claims, wherein the separation grid (8) has at least one fixing tab (87) with an opening, wherein the fixing tab (87) preferably extends radially, and wherein the fixing tab (87) is adapted to connect the separation grid (8) directly to a wall portion (4) of the electronics housing.

19. The degassing unit (10) according to any one of the preceding claims, wherein the degassing unit (10) has a cover (5) which is connected to the base body (1) on the outside, wherein the cover (5) preferably has at least one ventilation/venting opening (51).

20. Degassing unit (10) according to claim 19, wherein the cover (5) is fixed to the base body (1) by means of a snap-on element engagement.

21. The degassing unit (10) according to any one of the preceding claims, wherein the degassing unit (10) has a housing seal (7) which surrounds the gas passage opening (15) of the base body (1) on the inside (17) circumferentially.

22. The degassing unit (10) according to one of the preceding claims, wherein the degassing unit (10) has an emergency degassing pin (19) which extends on the outside in the axial direction towards the membrane (6) and whose tip (191) is present in the rest state at a predetermined distance from the outer membrane surface (61), wherein in particular the emergency degassing pin (19) is formed on the base body (1) or on the cover (5).

23. An electronics housing, in particular a battery housing of a traction battery of a motor vehicle, having at least one housing wall with a pressure compensation opening, wherein preferably battery cells can be arranged in the electronics housing, wherein the pressure compensation opening is closed by a degassing unit, characterized in that the degassing unit is a degassing unit (10) according to one of claims 1 to 22.

24. The electronics housing according to claim 23, characterized in that the degassing unit (10) is connected to a wall (4) of the electronics housing by means of at least one fastening means (3), in particular a screw, wherein the fastening means (3) is in engagement with a fastening means active region (11) of the base body, and wherein particularly preferably the separation grid (8) is indirectly or directly fixed between the wall (4) of the electronics housing and the base body (1) of the degassing unit (10) in a force-fitting and/or form-fitting manner.

25. Electronic housing according to claim 23 or 24, characterized in that the separating grid (8) is directly connected to a wall (4) of the electronic housing, in particular by at least one metallic fixing element, in particular at least one bolt, which is preferably guided through an opening (871) of at least one fixing tab (87) of the separating grid (8).

Technical Field

The invention relates to a degassing unit and to an electronics housing, in particular a battery housing of a traction battery of a motor vehicle.

Background

Housings for receiving electronic components, such as, for example, battery cells and the like, cannot be completely sealed off in a gas-tight manner from the surroundings, since, on the one hand, due to temperature fluctuations (for example, due to heat input caused by charging or discharging of the battery cells) and, on the other hand, due to naturally occurring air pressure fluctuations, in particular in mobile systems, gas exchange between the interior space and the exterior space must be possible in order to prevent impermissible mechanical loads of the housing, in particular bursting or bulging of the housing. However, it is also important to effectively prevent the intrusion of foreign matter, dirt, and moisture in the form of liquid water.

Therefore, pressure equalization devices are known which have a gas-permeable, liquid-impermeable, semi-permeable membrane.

If pressure peaks occur within the housing, for example in the event of a failure of a cell in the battery housing, the pressure must be reduced as quickly as possible, since otherwise the housing may be damaged.

As the simplest embodiment of the explosion protection, it is known, for example, for lead-acid batteries to use explosion-proof tabs (Berstscheibe), which are made in particular of sheet metal material, in the sense of "rated breaking points", or to use safety valves or valves which are inserted into the housing openings.

In contrast, highly specific pressure compensation devices are used in high-voltage batteries, in particular lithium-based traction batteries with significantly higher storage capacities and power densities, which are optimized for the task described above.

DE 102012022346B 4 discloses a degassing unit for a battery housing, which has a base body with a gas passage opening that is covered by a semi-permeable membrane that is permeable to gas but impermeable to liquid, wherein the membrane is connected to the base body in a positionally fixed and fluid-tight manner, in particular welded thereto. The base body can be connected in a fluid-tight manner to the pressure compensation opening of the battery housing. The semi-permeable properties of the membrane ensure gas exchange during normal operation, while for the emergency degassing function, an emergency degassing pin (nottgasungsdorn) is arranged on the cover and directed toward the membrane, which pin perforates and tears the membrane when it expands beyond a limit caused by the internal pressure of the housing, so that a sudden pressure equalization from the interior space to the surroundings can be achieved. In the assembled state, directed toward the inside of the battery housing, an internal protective grid is connected to the base body, which internal protective grid prevents foreign bodies from penetrating into the battery housing and supports the membrane against water pressure from the outside. The internal protective grid is connected to a base body, preferably made of plastic, by a hot-press connection and has a through-opening for screwing the base body to the battery housing, wherein the base body has a thread formed by a metallic threaded insert for engaging a screw for the screw connection.

The degassing units known from the prior art have the disadvantage that hot (lithium) particles, which are released in the event of a cell failure of a single or a plurality of battery cells, can pass unimpeded through the open emergency degassing opening into the surroundings, with the risk that surrounding components catch fire and, in the worst case, the vehicle equipped with such a battery will burn off.

Disclosure of Invention

The object of the present invention is therefore to provide a degassing unit for an electronics housing, in particular for a battery, in particular for a traction battery of a motor vehicle, which is characterized in that, in the event of a cell failure, hot particles are effectively blocked inside the electronics housing without excessively increasing the pressure loss in the emergency degassing path.

This object is achieved by a degassing unit having the features of claim 1 and by an electronics housing having the features of claim 23.

Preferred developments of the invention are specified in the dependent claims.

The advantages of the invention result from the description and the drawings. Likewise, the features mentioned above and those yet to be explained further can each be used individually or in any combination of a plurality. The embodiments shown and described are not to be understood as a final enumeration but rather have exemplary character for the description of the invention.

According to the present patent application, the term degassing unit is chosen for the device according to the invention. It goes without saying, however, that the device according to the invention likewise allows ventilation and venting of the interior of the electronics housing through the (porous) membrane, and therefore the device according to the invention may also be referred to as "pressure equalization unit" or "ventilation/venting unit".

The relative designations "interior" and "exterior" as used herein refer to an assembled state with respect to the electronics housing, wherein "interior" refers to facing the electronics housing and "exterior" refers to facing the ambient environment.

According to a first embodiment of the degassing unit for an electronics housing, in particular for a battery, in particular for a traction battery of a motor vehicle, the degassing unit has a base body which can be connected in a fluid-tight manner to an edge of a pressure compensation opening of the electronics housing, the base body having at least one gas passage opening which is covered by a semi-permeable membrane. The membrane allows the penetration of gaseous media from the surroundings into the electronics housing and vice versa, but prevents the penetration of liquid media and solids. The degassing unit furthermore has a membrane support device arranged on the inner side of the base body, which at least partially overlaps the gas passage opening and is present at a first distance from the semi-permeable membrane. The base body has, in particular on its inner and/or outer side, at least one fastening means active region which is provided for fastening the degassing unit to the electronics housing. According to the invention, a separation grid with a plurality of grid openings is arranged on the inner side of the base body at a second spacing from the semipermeable membrane which is greater than the first spacing, said separation grid completely overlapping the gas passage openings.

The size of the grid openings of the separating grid is selected such that the largest possible proportion of the particle fraction generated in the event of a cell failure can be blocked in order to prevent it from reaching the surroundings. The particles produced in the event of a failure of a cell are hot metal particles and/or alkali metal particles which, together with the combustible gases which are optionally produced in the event of a failure of a cell, can form an ignition source. For example, the dimensions of the grid openings of the separation grid are selected such that a specific mass fraction of the particles, for example > 75%, can be blocked. For this purpose, the separation grid is made of a sufficiently heat-resistant material, preferably a material having a melting temperature above 800 ℃, in particular above 1000 ℃. By arranging the membrane support device and the separation grid according to the invention at different distances from the membrane, wherein the separation grid is further away from the membrane, as little pressure loss as possible is ensured in the event of an emergency degassing.

The area spanned by the separation grid is larger than the cross-section of the gas penetration openings, which provides the advantage that the area available for particle separation is increased. This helps the separation grid not to clog (block) as quickly in the case of strongly particle-loaded gas flows. The device known from the prior art with only one support grid does not achieve this advantage, since the flow cross section available for particle separation is limited there by the size of the gas through-openings.

The first distance of the membrane support means from the membrane surface may be between 0.1 mm and 1.0 mm, preferably between 0.5 mm and 0.8 mm. However, the first distance can also be "zero", so that the membrane already rests against the membrane support in the rest state. The second spacing of the separation grid from the surface of the membrane may be greater than 0.5 mm, preferably greater than 1 mm, more preferably greater than 1.5 mm.

In a preferred embodiment, the membrane support is also fluid-permeable, preferably in the form of a grid section with a plurality of grid openings. This has the technical advantage that, in particular in the case of emergency degassing, the cross section of the membrane support can also be flowed through, which further reduces the pressure loss and thus increases the speed of the pressure drop in the housing.

Furthermore, the separation grid particles are preferably connected to the base body in a sealing manner.

According to another embodiment, the size of the grid openings of the separation grid may be less than 2.0 mm, preferably less than 1.2 mm, more preferably less than 0.9 mm in at least one direction of extension. According to the applicant's knowledge, the above-mentioned requirements regarding the separation performance of gravimetric determination can be achieved at such dimensioning.

The membrane can be present on the inner side of the base body and is at least partially engaged from behind by a support device (hingrectifen), so that the support device supports the membrane against external pressure effects (for example against water pressure in the case of wading and/or in the case of use of a cleaning device in a vehicle) and suppresses impermissible deformations.

The contact or connection of the membrane with the inside of the base body has the advantage that the membrane is held virtually form-locked with respect to the base body under internal pressure and the connection (welding, adhesive bonding, etc.) is not subjected to tensile forces, which can be important in particular when using PTFE materials which are difficult to join. In order to prevent an impermissibly strong deflection or "bulging" of the membrane, which would lead to destruction of the membrane, even under internal pressure, the base body can additionally have an outer membrane protective grid which spans the membrane surface at least in sections on the outside, but is fluid-permeable in a sufficiently large area proportion to enable gas exchange during normal operation.

Furthermore, the separation grid serves as an interference protection (Eingriffsschutz) into the interior space of the electronics housing, so that objects such as screwdrivers cannot reach into the interior. This is particularly important, since traction batteries for vehicles usually operate in the high-voltage range and are therefore at risk. The separating grid may have a plurality of spaced-apart grid bars, the minimum spacing of which is selected such that interventions can be reliably ruled out. The grid bars may be arranged in a rectangular grid or as a combination of grid bars extending in the circumferential and radial directions.

The separating grid can preferably be made of metal or of metal. An important advantage of a separating grid composed of metal is that the protective and separating function is maintained even after the action of high temperatures, so that such a separating grid is preferably used according to the invention. Alternatively, the separating grid can be made of plastic, preferably polypropylene and/or polybutylene terephthalate, which preferably have reinforcing fibers, in particular glass fibers.

The base body can be made predominantly of plastic, in particular thermoplastic, and in particular injection-molded. Preferred materials are polypropylene, polybutylene terephthalate or polyamide, each with reinforcing fibers, in particular glass fibers.

For semi-permeable membranes, all materials which have gas permeability for ventilation/venting in normal operation and which have sufficiently high water impermeability can be used. As a preferred material for the semi-permeable membrane Polytetrafluoroethylene (PTFE) may be used. The semi-permeable membrane sheet has an average pore size that may be between 0.01 microns and 20 microns. The porosity is preferably about 50%; the average pore size is preferably about 10 microns.

The semipermeable membrane can preferably be designed as a thin membrane in the form of a membrane or disk. The gas-permeable membrane has a membrane surface which is effective for gas permeation and which preferably has a rectangular or circular outer contour on its outer circumference. It goes without saying, however, that the outer periphery of the membrane can also be designed differently. The membrane preferably means a thin flat membrane whose membrane surfaces which are directed away from one another and which act on gas penetration are configured substantially parallel to one another and preferably substantially flat.

The membrane thickness of the membrane is much smaller than its other outer dimensions. The membrane may span a minimum width and/or a minimum length or a minimum outer diameter equal to or greater than 20 mm, preferably equal to or greater than 30 mm, in particular equal to or greater than 40 mm. The membrane thickness can in particular be at least 20 times, preferably at least 40 times, in particular at least 100 times, smaller than the minimum width and/or the minimum length or the minimum outer diameter of the membrane. The membrane thickness may be from 1 μm to 5 mm, with membrane thicknesses of from 0.1 to 2 mm, in particular from 0.15 to 0.5 mm, being preferred.

In a further embodiment, the separation lattice can bulge in the assembled state in a pot-like manner in the direction pointing inwards. By means of the pot-shaped elevations, a larger effective surface is provided for particle separation, which further reduces the pressure loss, in particular in the case of emergency degassing.

As an alternative, the separation grid can be configured substantially flat, which offers advantages in the case of limited installation space inside the electronics housing, since the minimum distance to be observed between the conductive members can thereby be observed more easily if necessary.

In a preferred refinement, the degassing unit has at least one spacer which holds the separation grid at a second distance from the membrane and which is either configured to project axially inward from the base body or is configured to project axially outward from the separation grid. If the spacer is configured so as to project axially inward from the base body, the separation lattice rests on the free end of the spacer, while, when the spacer is configured, the free end of the spacer rests axially outward from the separation lattice on the base body. In particular, a plurality of spacers can be provided, which are arranged in a distributed manner, in particular over the circumference.

According to a particularly preferred embodiment, the size of the grid openings of the membrane support device is larger than the size of the grid openings of the separation grid. For example, the size of the grid openings of the membrane support device in the direction of extension with the smallest dimension may be at least 4 times, preferably at least 6 times larger than the size of the grid openings of the separation grid. This is based on the idea that such a fine-meshed grid is not required in order to fulfill the membrane support function. In this case, a protective function for ensuring tamper protection (IP classification) is realized by correspondingly dimensioned grid openings of the separation grid.

The separation grid and the membrane support means may be constructed independently of each other. In a particular embodiment, the membrane support device can be formed in one piece with the base body or can be connected to the base body in a detachable or non-detachable manner.

Alternatively, the separation grid and the membrane support device can also be constructed in one piece.

In particular, the membrane support device, in particular the grid section of the membrane support device, can be designed as an axial support ridge of the separation grid, wherein the support ridge is preferably present centrally with respect to the gas passage opening. The membrane support means provided by the support ridges are closer to the membrane than the separation grid itself, wherein the support ridges are raised in a direction pointing outwards in the assembled state. In this case, the separating grid with the "integrated" membrane support can be produced in a particularly simple and cost-effective manner from flat sheet metal sections by means of deformation and stamping.

In a further embodiment, the separation grid can carry a filter medium which preferably comprises a grid material, in particular a metal wire grid (drahtgilter) and/or a nonwoven material. The filter medium is in particular made of or has a metallic material. The filter medium can be supported by the supporting grid strips of the separating grid, which in combination with the filter medium can have a significantly greater spacing from one another than in the embodiment without the filter medium; the spacing between the supporting grid bars can be, for example, several millimeters, for example 1.5 mm to 35 mm, preferably 2 mm to 30 mm. The cross-section of the openings relevant in terms of separation is in this case determined by the size of the openings of the grid material and/or by the pore size of the nonwoven material.

Furthermore, the separating grid can be connected to the base in a non-detachable or detachable manner, in particular in a snap-in manner (Verschnappen). In order to ensure that the particle tightness of the connection of the separation grid to the base body is as good as possible, the separation grid can overlap the base body radially on the outside at least over part of the circumference. In a preferred embodiment, the latching means are present in the region of the radially outer enclosure (ummiriff).

In a particularly preferred embodiment, the spacing between the separation grid and the membrane support device can be at least 0.2 mm, preferably at least 0.7 mm, in the region of the center of the gas passage opening, wherein even larger values are more advantageous in view of the small pressure loss.

Furthermore, the fastening means active region of the base body can comprise a hole, in particular a blind hole, which is open, in particular, to the inside/outside of the base body. The corresponding fastening means can engage the opening, in particular from the interior of the housing or from the exterior of the housing of the electronics housing.

The separating grid is preferably designed as a sheet metal part, in particular as a stamped sheet metal part. This also enables cost-effective manufacturing in large-scale applications. Alternatively or additionally, the openings of the separation grid can also be produced by other methods, for example by (laser) cutting. Preferably, the separation grid has at least one through-opening, which is aligned with the at least one blind hole of the base body. In order to fix the degassing unit on the electronics housing, a screw can be guided through the through-opening, which screw, according to this embodiment, also keeps the separation grid securely fixed with respect to the opening of the electronics housing under the effect of heat.

Furthermore, the membrane can be connected, in particular welded, around the edge of the gas passage opening of the base body, preferably on the inner side of the base body. Alternatively, the membrane can also be held adhesively or non-positively, for example clamped. The porous PTFE membrane material described here as preferred can be welded or otherwise bonded to the plastic base body without any problems.

In a further preferred embodiment, the separation grid has at least one fastening tab with an opening. The fastening webs extend in particular in the radial direction out of the grid body of the separating grid. The fixing tabs are adapted to connect the separation grid directly to a wall portion of the electronics housing. The direct connection of the, in particular, metallic, separation grid to the, in particular, metallic, wall of the electronics housing has the advantage that the separation grid remains fixed with respect to the wall of the electronics housing after a strong thermal action (for example, a fire and/or a cell failure) and can also exert its separating function.

The degassing unit can furthermore have a cover which is connected to the base body on the outside, wherein the cover preferably has at least one ventilation/venting opening.

The cover ensures that the membrane is not damaged from the outside by foreign objects, for example sharp objects, such as screwdrivers or the like, nor by the high-pressure cleaner and/or the steam injector, thereby effectively contributing to a high IP protection level.

In a further, likewise preferred embodiment, the cover is fixed to the base body by means of a detent element (hastellentingriff). The latching element can be engaged here, for example, on the outer circumference of the base body or, in the broader sense, on the outer side of the base body on the end side. However, other fastening means are also conceivable for fastening the cover to the base body, for example form-locking or force-locking fastening means, such as screws or clips, or by material-locking connections, in particular (friction) welding.

Plastic, preferably thermoplastic, which can be processed by injection molding, is particularly suitable as the material for the base body and/or the cover. Preferably, the base body and/or the cover are made of polypropylene, polybutylene terephthalate or polyamide, each optionally with reinforcing fibers, in particular glass fibers, or at least with at least one of these materials.

Alternatively or additionally, the degassing unit can have a housing seal which surrounds the gas passage openings of the base body on the inner side of the base body. The housing seal can be designed as an axial or radial seal, i.e. in particular on the end face (in the case of an axial seal) or on the outer circumferential face (in the case of a radial seal). The housing seal can be configured as an O-ring which is received in a corresponding groove of the base body, or as a sealing component of the injection. Preferably, the housing seal is arranged in an axial configuration, wherein it is particularly preferred that the housing seal encloses a bayonet connection, which projects in particular axially. The housing seal can also be designed in particular as a form seal having a non-circular cross section, in particular extending in the longitudinal direction.

Furthermore, the degassing unit can have an emergency degassing pin which extends on the outside in the axial direction toward the membrane and whose tip is present at a predetermined distance from the outer membrane surface in the rest state. The emergency degassing spike can be formed on the base body or on the cover. The emergency degassing pin is arranged in the rest state (without differential pressure loading) at a predetermined distance from the surface of the membrane. Under pressure loading (relative internal overpressure), the membrane bulges in the direction of the outer space and comes to bear against the tip of the emergency degassing spike when the limiting pressure is reached. The emergency degassing spike then produces, due to its tip, a targeted weakening of the membrane, causing the membrane to tear. This serves to ensure an emergency degassing function which reacts as sensitively as possible, which is important to ensure that the housing structure remains intact in the event of a sudden increase in the internal pressure in the electronics housing. The emergency degassing pressure can be adjusted by changing the distance of the tip of the emergency degassing pin from the surface of the membrane.

Another aspect of the invention relates to an electronics housing, in particular a battery housing of a traction battery of a motor vehicle. As a possible use of the degassing unit according to the invention in addition to the traction battery, for example, a switchgear cabinet or a transformer housing is obtained. The electronics housing has at least one housing wall with a pressure compensation opening, wherein preferably a cell can be arranged in the electronics housing, and wherein the pressure compensation opening is closed by the degassing unit according to the invention, so that a gas exchange between the interior of the electronics housing and the surroundings is possible, while nevertheless an intrusion of moisture, dirt and foreign matter is effectively prevented.

In particular, the assembly of the degassing unit is provided such that the degassing unit is connected to a wall of the electronics housing by means of at least one fastening means, in particular a screw, wherein the fastening means is in engagement with the fastening means active region of the base body. The sealing pretension required for pressing the housing seal is generated by the threaded connection. The screw connection can be carried out in particular from the interior of the electronics housing. The invention naturally also encompasses embodiments in which the screw connection of the degassing unit to the electronics housing is made from the outside.

It is particularly preferred that the separation grid is fastened indirectly or directly between the wall of the electronics housing and the base body of the degassing unit in a form-fitting manner, to a certain extent sandwiched between them. This makes it possible for the separating screen to remain reliably fixed with respect to the opening of the electronics housing even under the action of heat.

According to a preferred embodiment, the separation grid can be connected directly to a wall of the electronics housing, in particular by at least one metallic fastening element, in particular by at least one bolt. Preferably, the screw is guided through an opening of at least one fixing tab of the separation grid. The direct connection of the separation grid to the wall of the electronics housing, in particular of metal, has the advantages described in the preceding paragraph.

Finally, the housing wall can have a sealing surface on the outside, which surrounds the pressure compensation opening and against which the housing seal of the degassing unit rests in the assembled state. The sealing surface is preferably formed as a region of a wall of the electronics housing, which has as little deviation from planarity and as little roughness as possible. The electronics housing or at least its wall is expediently of a metallic material or is composed of a metallic material, so that the sealing surface can be easily obtained by machining with regard to the above-mentioned properties.

Drawings

Other advantages are given by the following description of the figures. Embodiments of the invention are illustrated in the drawings. The figures, description and claims contain many combinations of features. Suitably, a person skilled in the art also considers these features individually and generalizes them to other combinations of meanings. In which is shown:

figure 1 shows an isometric cross-sectional view of a degassing unit according to the invention according to a first embodiment;

figure 2 shows another isometric cross-sectional view of a degassing unit according to the invention according to a first embodiment;

figure 3 shows an isometric view of a degassing unit according to the invention according to a second embodiment;

figure 4 shows an isometric cross-sectional view of a degassing unit according to the invention according to a second embodiment;

figure 5 shows another isometric view from the outside of a degassing unit according to the invention according to a second embodiment;

figure 6 shows an isometric view of a degassing unit according to the invention according to a third embodiment;

figure 7 shows an isometric cross-sectional view of a degassing unit according to the invention according to a third embodiment;

FIG. 8 shows detail A in FIG. 7;

figure 9 shows an isometric view of a degassing unit according to the invention according to a fourth embodiment;

figure 10 shows an isometric cross-sectional view of a degassing unit according to the invention according to a fourth embodiment;

figure 11 shows an isometric cross-sectional view of a degassing unit according to the invention according to a fifth embodiment.

Detailed Description

In the drawings, the same or similar components are denoted by the same reference numerals. The drawings are only for purposes of illustration and are not to be construed as limiting. Features or combinations of features disclosed in connection with a particular embodiment are also intended to be transferred to other embodiments unless explicitly excluded.

All the figures show a degassing unit 10 according to the invention, in the installed state, in particular for a battery, in particular for a traction battery of a motor vehicle, and a section of the wall 4 of the electronics housing.

A first embodiment of a degassing unit 10 according to the invention is shown in isometric cross-section in fig. 1 and 2. The degassing unit has a base body 1 which is connected via a screw connection to the outside to the edge of a pressure compensation opening of an electronics housing, in particular of a battery housing of a traction battery. The threaded connection has a plurality of screws 3, which are screwed into corresponding fastening means active regions 11 of the base body. The bolts 3 extend through-holes 41 in the wall 4 of the electronics housing, respectively. The degassing unit 10 is fitted on the outside on the electronics housing and screwed from the inside. In order to seal the base body 1 of the degassing unit 10 in a fluid-tight manner against the wall 4 of the electronics housing, a housing seal 7 is provided which is pressed by a sealing prestress exerted by the screw 3. The housing seal 7 is arranged in the seal receptacle 16 of the base body 1 and is held therein by a "bulged" cross-sectional area, so that it cannot fall out of it during assembly.

Furthermore, the base body has gas passage openings 15, through which a pressure equalization between the interior of the housing and the surroundings and vice versa can be achieved.

Furthermore, the degassing unit 10 has a semi-permeable membrane 6 which is permeable to gaseous fluids, but which prevents the penetration of solids and liquids. Preferably, the membrane is configured as a porous PTFE membrane. The semipermeable membrane 6 is connected, preferably welded or glued, to the base body 1 in a fluid-tight manner on the inner side 17, around the gas passage openings 15 of the base body 1, i.e. to the edge 151.

The gas passage opening 15 and the membrane 6 are further covered by a fluid-permeable membrane support 2 which is present at a first distance from the membrane 6. The membrane support 2 has a plurality of grid bars 21, between which a plurality of grid openings 24 are present. In the present exemplary embodiment, the diaphragm support 2 is designed as a stamped sheet metal part.

On the outer side 18 of the base body 1, a cover 5 is connected to the latter, which cover has at least one ventilation/venting opening 51 and is provided to protect the sensitive membrane 6 so that it is not damaged from the outside by foreign bodies, for example sharp objects such as screwdrivers or the like, nor by high-pressure cleaners and/or steam injectors. Thus, the structural and dimensional design of the cover contributes significantly to a high IP protection level.

Furthermore, the degassing unit 10 has a separation grid 8 with a plurality of openings 81. The separation grid 8 is present at a second distance from the membrane 6, which is larger than the first distance from which the membrane support means 2 are present. Furthermore, the openings 81 of the separation grid 8 are smaller than the openings 24 of the membrane support 2 and provide tamper protection, so that non-long and sharp objects (e.g. wires, screwdrivers, etc.) can be introduced into the interior of the housing. The separating grid 8 is configured as a raised pot 82 which is raised in an inwardly directed direction. Particles can be trapped inside the housing by the separating grid 8, which particles are released in the event of a cell failure of a single or a plurality of battery cells. The dimensions of the grid openings 81 of the separating grid 8 are selected such that as large a proportion as possible of the particle fractions can be blocked thereby in order to prevent these from reaching the surroundings. The dimensions of the grid openings 81 of the separating grid are selected, for example, such that a specific mass fraction of particles, for example > 75%, can be blocked. The pot-like shape of the separation grid 8 increases the surface available for separating particles compared to a flat embodiment and thus also reduces the tendency to clog the separation grid 8 in the case of strongly particle-loaded gas flows. Furthermore, the enlarged surface of the separation grid 8 has the advantage that the thermal peaks are distributed over a larger area, which reduces the risk of structural damage caused by heat.

According to the embodiment shown, the separation grid 8 is connected to the base body particles in a particle-tight manner, in that the separation grid is sandwiched between the wall 4 of the electronics housing and the base body 1. In order to facilitate the assembly of the degassing unit 10, the separation grid 8 can additionally be at least pre-fixed with respect to the base body 1; for this purpose, all connection types that appear suitable to a person skilled in the art can be considered (for example gluing).

Furthermore, the base body 1 has an emergency degassing spike 19. The base body extends toward the diaphragm 6 and is arranged at a predetermined distance from the outer diaphragm surface 61 in the rest state (no differential pressure loading). Under pressure loading (against internal overpressure), the membrane 6 bulges in the direction of the outer space and comes to bear against the tip 191 of the emergency degassing pin 19 when the limit pressure is reached. The emergency degassing spike 19 then produces a targeted weakening of the membrane 6 due to its tip 191, thereby tearing the membrane. This serves to ensure an emergency degassing function which reacts as sensitively as possible, which is important to ensure that the housing structure remains intact in the event of a sudden increase in the internal pressure in the electronics housing. The emergency degassing pressure can be adjusted by varying the spacing of the tip 191 of the emergency degassing pin 19 from the diaphragm surface 61.

According to a second embodiment, which is illustrated in fig. 3 to 5, the membrane support 2 is constructed in one piece with the separation grid 8. The degassing unit 10 is arranged on the inside on the wall 4 of the electronics housing and screwed from the outside.

The separating grid 8 has an enclosing region 85 which surrounds the base body 1 radially on the outside in a circumferential manner. The detachable fastening of the separating grid 8 to the base body 1 takes place in the surrounding region 85 by means of the snap-in means 84 of the separating grid 8, which snap into corresponding snap-in recesses of the base body 1. This circumferential enclosure of the separation grid 8 on the one hand increases the rigidity of the separation grid 8 and on the other hand contributes to an improved particle tightness. According to this embodiment, the membrane support device 2 is configured as an axial ridge 83 or depression of the separation grid 8. The membrane support device 2 is provided by an axially offset, fluid-permeable grid section of the separation grid 8, which is arranged approximately in the center of the gas passage opening 15 and is present at a first spacing from the membrane 6, while a non-axially offset section of the separation grid 8 is present at a second spacing from the membrane 6, which is greater than the first spacing. This embodiment has the decisive advantage that the separating grid 8 with the integrated membrane support 2 can be produced by means of a single process (for example stamping and deformation) and that the assembly effort is minimized, since only one assembly step (snap-fitting of the separating grid 8) is required. Furthermore, the base body 1 has a plurality of spacers 12, which extend away from the separation grid 8 in the axial direction inwardly and rest thereon in order to maintain the separation grid 8 at a predetermined second distance from the membrane 6. The spacers 12 are arranged distributed over the circumference around the gas passage openings 15 in order to support the separation grid 8 as uniformly as possible. In an embodiment that is not illustrated, the spacer elements can also be formed on the separation grid 8 and extend outward in the radial direction in order to rest on the main body 1.

Fig. 5 shows the degassing unit 10 according to the invention from the outside in the assembled state without an assembled cover. With regard to the threaded connection and sealing, the second embodiment corresponds to the first embodiment described further above.

A third embodiment of a degassing unit 10 according to the invention is shown in fig. 6 to 8. Functionally, this corresponds to the first and second embodiments described further above, so only the differences between them will be discussed. The main difference with respect to the second embodiment is the separate design of the separation grid 8 and the membrane support 2. The membrane support device 2 is formed as a part of the base body 1 or is connected to it in a material-locking manner, in particular welded, and the membrane support device 2 has in particular a honeycomb-like lattice structure 21, between which lattice openings 24 are present.

The shape of the grid structure 21 may also be different from the honeycomb shape in embodiments not shown in the figures. The membrane support means 2 are in turn arranged at a first distance from the membrane 6. The one-piece construction with the base body 1 has the advantage that the membrane support 2 can be manufactured together with the base body 1 (for example by injection molding). The membrane support 2 can be made of the same material as the base body 1, for example of a thermoplastic, for example of polypropylene, polybutylene terephthalate or polyamide, which each have reinforcing fibers, in particular glass fibers, and can therefore be welded to the base body 1 without problems. A separating grid 8, which is of flat design (without elevations or depressions), is detachably connected to the base body 1. With regard to the function of the spacer 12 and the fastening of the separating grid 8 to the main body 1 in the surrounding region 85, reference is made to the statements made with regard to the second embodiment. Fig. 8 shows the detachable connection of the separating grid 8 to the base body 1 by means of a snap-in mechanism 84 of the separating grid 8, which engages in a corresponding snap-in recess 13 of the base body 1, which is shown again as detail a.

A fourth embodiment of a degassing unit 10 according to the invention is shown in fig. 9 and 10. This embodiment is basically duiying from the third embodiment, however, differs in the configuration of the separation grid 8. The separation grid 8 carries the filter medium 9 with the support grid strips 86, which covers the openings 81, which are significantly larger in the fourth embodiment. The filter medium 9 has a grid of metal wires defining an effective minimum opening cross-section. Alternatively or additionally, the filter medium may also comprise a nonwoven material, which may be present in particular on the outside adjacent to the metal wire grid, wherein the effective minimum opening cross section is then determined by the pore size of the nonwoven. This embodiment has the advantage that by using a separate filter medium 9, a significantly smaller effective opening cross section can be achieved, so that a greater weight fraction of the finer particle fraction or of the entire particle fraction can also be separated off. The filter medium preferably comprises or consists of a metallic material, for example steel, which is advantageous due to the good heat resistance. Such wire grid and/or nonwoven media are commercially available.

Fig. 11 shows a fifth embodiment of the degassing unit 10 according to the invention. This embodiment corresponds substantially to the fourth embodiment according to fig. 9 and 10. The difference is that the degassing unit 10 according to the fifth embodiment has, on its separation grid 8, fixing tabs 87 which extend radially away from the grid body of the separation grid 8. In the fastening tab 87, there is an opening 871 through which a metal screw is guided, by means of which the separating grid 8 is directly connected to the wall 4 of the electronics housing. The technical advantages associated therewith are explained fully in the integral part of the description.

List of reference numerals

10 degassing unit

1 base body

11 region of action of the securing means

12 spacer

13 snap recess of base

15 gas penetration opening

151 edge of gas penetration opening

16 sealed containing groove of base body

17 inside the base body

18 outside of the substrate

19 Emergency degassing pin

191 tip of emergency degassing pin

2 support device

21 grid bar

24 grid opening

3 bolt

4 wall part of electronic device housing

41 through hole of wall of electronic device case

5 cover

51 Ventilation/exhaust opening

6 semi-permeable membrane

61 outer diaphragm surface

7 casing seal

8 separation grid

81 openings for separation grids

82 pot-shaped raised part of separation grid

83 axial supporting ridges of the separation grid

84 snap mechanism for separating grids

85 surrounding area of separation grid

86 support grid bars for separation grid

87 fixation tab for separation grid

871 openings in fixation tabs

9 a filter medium.