Degassing unit and housing, in particular battery housing

Abstract

Degassing unit (10) for a housing (4), with a base body (1) which can be connected in a fluid-tight manner to an edge of a housing opening (44) of the housing (4), having an outer surface (18) and an inner surface (17), and which has at least one gas passage opening (15) which is closed with a membrane (6) stretched across a surface transverse to an axial direction (L), wherein the base body (1) is operatively connected to an actuator (2) which has an emergency degassing mandrel (19) extending in the axial direction (L) to the membrane (6) and whose tip (191) or at least a cutting edge (192) is arranged at a predetermined distance from a membrane surface (61, 62) in a rest state, wherein the emergency degassing mandrel (19) is movable towards the membrane when the actuator (2) is activated, so that the tip (191) or cutting edge (192) can pierce or cut the membrane (6), wherein the actuator (2) is arranged on the base body (1) or can be arranged on the housing (4), characterized in that a cover (5) is arranged on the outside (18) of the base body (1), which covers the gas passage opening (15) and which is connected to the base body (1) via a fastening mechanism, wherein the actuator (2) has an actuating element (21) which is designed to release the fastening mechanism.

Description

Technical field

[0001] The invention relates to a degassing unit and an electronics housing, in particular a battery housing, especially a traction battery of a motor vehicle. State of the art

[0002] Housings for electronic components such as battery cells and the like cannot be completely sealed gas-tight from the environment, because on the one hand, due to temperature fluctuations, for example due to heat input during charging or discharging of battery cells, and on the other hand, due to naturally occurring air pressure fluctuations, especially in mobile systems, gas exchange between the interior and exterior must be allowed in order to prevent impermissible mechanical stresses on the housing, in particular bursting or bulging of the housing.

[0003] Equally important, however, is the effective prevention of the ingress of foreign matter, dirt, and moisture in the form of liquid water. Therefore, pressure equalization devices are known that incorporate semipermeable membranes, for example, made of extruded polytetrafluoroethylene (PTFE), which are permeable to gas but impermeable to liquids.

[0004] DE 10 2012 022 346 B4 discloses a battery housing comprising a housing enclosing an interior space, with a housing opening covered by a membrane carrier in the form of a housing cover. This carrier is designed for degassing and for a substantially watertight seal of the housing interior against the ingress of water, and preferably also other liquids. The housing cover contains a carrier body with a gas passage opening extending continuously between an inner and an outer surface of the carrier body for the purpose of gas venting or pressure equalization. The gas passage opening is completely covered by a semipermeable membrane. The carrier body, the membrane, and the housing are hermetically or gas-tightly connected in such a way that substantially no water or particles can enter the housing interior through the housing opening.

[0005] US 2005 / 0205129A1 and US 2005 / 0138930A1 disclose overpressure protection devices. Disclosure of the invention

[0006] One object of the invention is to create a degassing unit for a housing, in particular a battery, especially a traction battery of a motor vehicle, which allows for rapid pressure reduction in the event of overpressure occurring in the housing.

[0007] Another task is to create a housing, in particular a battery housing, especially for a traction battery of a motor vehicle, which allows for rapid pressure relief in the event of overpressure occurring in the housing.

[0008] Another task is to specify a method for degassing a housing, in particular a battery, especially a traction battery of a motor vehicle, with a degassing unit, which allows for rapid pressure reduction in the event of overpressure occurring in the housing.

[0009] The aforementioned problem is solved according to one aspect of the invention by a degassing unit for a housing, in particular a battery, in particular a traction battery of a motor vehicle, with a base body that can be connected fluid-tight to an edge of a housing opening of the housing, having an outer surface and an inner surface, and which has at least one gas passage opening which is closed with a membrane stretched across a surface transverse to an axial direction, wherein the base body is operatively connected to an actuator which has an emergency degassing mandrel which extends in the axial direction to the membrane and whose tip or at least a cutting edge is arranged at a predetermined distance from a membrane surface in a rest state, wherein the base body or the housing has the actuator.

[0010] The further problem is solved according to a further aspect of the invention by a housing, in particular a battery housing, in particular a traction battery of a motor vehicle, for receiving battery cells, which has at least one housing wall with a housing opening, wherein the housing opening is closed by a degassing unit.

[0011] According to a further aspect of the invention, the further problem is solved by a method for degassing a housing, in particular a battery, in particular a traction battery of a motor vehicle, with a degassing unit, wherein an actuator is actuated by a control signal of the battery and / or the vehicle and with an emergency degassing pin pierces a membrane which closes a gas passage opening, so that gas escapes through the gas passage opening from the housing.

[0012] Favorable embodiments and advantages of the invention will become apparent from the further claims, the description and the drawing.

[0013] According to one aspect of the invention, a degassing unit for a housing, in particular a battery, and especially a traction battery of a motor vehicle, is proposed. This unit comprises a base body, which can be connected in a fluid-tight manner to the edge of a housing opening, and which has an outer and an inner surface. The base body has at least one gas passage opening, which is closed by a membrane stretched across a surface transversely to an axial direction. The base body is operatively connected to an actuator, which has an emergency degassing pin extending axially to the membrane, the tip of which, or at least one cutting edge, is arranged at a predetermined distance from a membrane surface in a rest state. The base body or the housing incorporates the actuator.

[0014] The degassing unit is specifically designed as a pressure equalization device with an integrated emergency opening for a high-voltage battery housing, through which gaseous fluids can flow for pressure equalization and, in particular, in the event of a collapsing battery cell, the so-called thermal runaway.

[0015] The emergency venting pin is positioned at a predetermined distance from the diaphragm surface when the actuator is at rest. Upon activation, the actuator's actuating element, along with the emergency venting pin, moves towards the diaphragm, allowing the pin's tip or at least one cutting edge to pierce or cut through it. Due to its tip or at least one cutting edge, the emergency venting pin creates a controlled weakening or local tear in the diaphragm, causing it to rupture. This ensures a rapid emergency venting function, proactively activated by the active control mechanism. This is crucial to guarantee that the housing structure remains intact in the event of a sudden increase in internal pressure within the electronics enclosure.By actively controlling the actuator in a targeted and proactive manner, the opening cross-section for emergency degassing can be released before the actual pressure increase occurs, allowing it to be reduced particularly quickly and in a defined way.

[0016] The diaphragm is actively ruptured by the actuator's emergency degassing pin acting upon it, regardless of the applied pressure. The actuator can be actuated pneumatically, hydraulically, mechanically (e.g., by a spring), electrically, magnetically, or by a combination of two or more of these principles. For example, a linear magnet or a solenoid can be used. Alternatively, an actuator with a spring-loaded needle, released by a linear magnet or solenoid, can be employed. Optionally, an actuator can also be designed as a servo motor. Such servo motors are described, for example, at https: / / www.ags-stellantriebe.de / de / stellantriebe / hubantriebe-und-linearantriebe.

[0017] The membrane rupture occurs in this way independently of the material properties and geometry, the temperature, and the pressure differential across the membrane. Membrane rupture can be precisely and selectively induced based on measured pressure and / or temperature values, or using characteristic curves derived from data from various sensors, which allow conclusions to be drawn about the operating state. The opening of the gas passage by membrane rupture occurs directly and independently of the membrane's temperature-dependent material properties.

[0018] Suitable materials for the base body and / or the cover include, in particular, plastics, preferably thermoplastic plastics that can be processed by injection molding. Preferably, the base body and / or the cover consists of polypropylene, polybutylene terephthalate, or polyamide, each optionally comprising reinforcing fibers, in particular glass fibers, or comprising at least one of these materials.

[0019] According to a favorable embodiment of the degassing unit, a cover can be arranged on the outside of the base body, which covers the gas passage opening and is connected to the base body. In particular, the cover can be connected to the base body via a fastening mechanism, especially a snap-fit ​​mechanism. The actuator can have an actuating element designed to release the fastening mechanism.

[0020] Advantageously, the actuator, with its actuating element, can release the fastening mechanism, which can preferably be designed as a snap-fit ​​mechanism for easy installation of the cover. The cover can thus be removed from its normal position, for example, by the pressure of the flowing gas or by being pushed by the actuating element. This allows the fluid path for the escaping gas, which leads through the gas passage opening, to be advantageously enlarged in cross-section. Particularly advantageously, the cover can be lifted off by the actuator, especially by the actuating element, and completely removed from its normal position in the resting state.

[0021] According to a favorable embodiment of the degassing unit, the cover can have an actuating dome designed to interact with the actuator's actuating element to release the cover's fastening mechanism. In its resting state, the actuating element is positioned at a predetermined distance from the base of the actuating dome. When the actuator is actuated, the actuating element can be brought into contact with the cover's actuating dome, and with further actuation of the actuator, the cover is lifted above the dome. This releases the cover's fastening mechanism. The cover can then be completely lifted and removed, thus largely exposing the degassing unit's through-hole.

[0022] According to a favorable embodiment of the degassing unit, the actuator can be arranged on the inside of the base body or on an outside of the housing. Alternatively, the actuator can also be arranged on an inside of the housing. Advantageously, the actuator can be arranged on the base body and thus connected to it. Alternatively, however, the actuator can also be arranged outside the housing on the outside. In this way, the actuator does not necessarily have to be directly connected to the degassing unit.

[0023] According to a favorable embodiment of the degassing unit, the emergency degassing pin can be arranged on an actuating surface of the actuating element facing the diaphragm. In this arrangement, the diaphragm can be easily pierced with the emergency degassing pin and thus ruptured.

[0024] According to a favorable embodiment of the degassing unit, the base of the actuating dome can have a receiving area for the emergency degassing pin, so that, in the event of actuation, the actuating surface of the actuating element rests flat against the base of the actuating dome and the tip or at least one cutting edge of the emergency degassing pin is received by the receiving area. In such an embodiment, the actuating surface of the actuating element can directly contact the actuating dome of the cover and exert the corresponding pressure to release the cover's fastening mechanism.

[0025] According to a favorable design of the degassing unit, the actuator can be configured as an electrically actuated actuator, in particular as an electromagnetic actuator. The actuator can advantageously be configured with a linear magnet or a lifting magnet. This ensures reliable and rapid actuation of the actuator. Furthermore, the actuator can be conveniently controlled with electrical control signals.

[0026] According to a favorable design of the degassing unit, the actuator can be configured for direct actuation of the actuating element. Alternatively, the actuator can be configured for indirect actuation of the actuating element, in particular by releasing a preload mechanism. Actuation of the actuator can be achieved directly via pneumatic, hydraulic, or mechanical means (e.g., by a spring), electrically, magnetically, or by a combination of these principles. For example, a linear magnet or a solenoid can be used. In the case of indirect actuation, an actuator with a spring-loaded needle can also be used, the fixation of which is released by a linear magnet or solenoid.

[0027] In a favorable design of the degassing unit, the actuator can have at least one signal input for a control signal from the battery and / or the vehicle. The actuator can thus be activated when, for example, the battery control unit signals an impending pressure increase due to a failing cell. Alternatively, the actuator can also be activated, for example, in the event of a vehicle accident via a crash signal.

[0028] According to a favorable design of the degassing unit, the membrane can be arranged on the inner side of the base body. Attaching or connecting the membrane to the inner side of the base body has the advantage that, under internal pressure, the membrane is held in a virtually form-fit relationship to the base body, and the connection (welding, bonding, or the like) is not subjected to tensile stress. This can be particularly important when using PTFE materials, which are inherently difficult to join. To prevent excessive deflection or deformation even under pressure, such as internal or external pressure from water, the membrane is also designed to be securely attached to the base body.To prevent "bulging" of the membrane, which can lead to its destruction, the base body can additionally have an outer membrane protective grid that at least partially covers the outer membrane surface, but is fluid-permeable with a sufficiently large area to allow gas exchange during normal operation and not to unduly impair the fluid flow during emergency degassing.

[0029] According to a favorable design of the degassing unit, the membrane can be designed as a gas-impermeable membrane, in particular as a polymer film. Advantageously, a non-gas-permeable membrane, for example a polymer film, can be used to ensure the tightness of the housing during intended operation.

[0030] According to a favorable design of the degassing unit, the membrane can be designed as a semipermeable membrane, which allows the passage of gaseous media from an environment into the housing and vice versa, and prevents the passage of liquid media and / or solids.

[0031] Any material that exhibits sufficient gas permeability for ventilation during normal operation and adequate water impermeability can be used for the semipermeable membrane. Polytetrafluoroethylene (PTFE) is a preferred material for the semipermeable membrane. The semipermeable membrane has an average pore size that can range from 0.01 micrometers to 20 micrometers. The porosity is preferably around 50%; the mean pore size is preferably about 10 micrometers.

[0032] The semipermeable membrane can preferably be designed as a thin, film-like, foil-shaped, or disc-shaped membrane. The gas-permeable membrane has a membrane surface effective for gas permeation, which preferably has a rectangular or round outer contour. However, it is understood that the outer circumference of the membrane can also be designed differently. The membrane is preferably a thin, flat membrane whose surfaces, effective for gas permeation and facing away from each other, are essentially parallel to each other and preferably essentially planar.

[0033] The membrane thickness is significantly smaller than its other external dimensions. The membrane can span a minimum width and / or length or a minimum outer diameter of 20 mm or greater, preferably 30 mm or greater, and in particular 40 mm or greater. The membrane thickness can be at least 10 times, more specifically 20 times, preferably at least 40 times, and in particular at least 100 times, smaller than the minimum width and / or length or the minimum outer diameter of the membrane. The membrane thickness can range from 1 micrometer to 5 millimeters, with a membrane thickness of 0.1 to 2 mm, and in particular 0.15 to 0.5 mm, being preferred.

[0034] Furthermore, the membrane can be connected around its perimeter to an edge of the gas passage opening of the base body, in particular by welding, preferably on an inner side of the base body. Alternatively, the membrane can also be bonded. The porous PTFE membrane materials described herein as preferred can be easily welded to a plastic base body or otherwise bonded in a material-bonded manner.

[0035] According to a favorable design of the degassing unit, the base body can have at least one fastening element area which is designed to fasten the degassing unit to the housing.

[0036] Advantageously, the fastening element engagement area of ​​the base body can include a bore, in particular a blind hole, which is open to the inside and / or outside of the base body. A corresponding fastening element can be engaged through this bore, particularly from the inside or outside of the electronic housing.

[0037] According to a favorable design of the degassing unit, the degassing unit can have a housing seal which surrounds the gas passage opening of the base body on the inside.

[0038] The housing seal can be designed as an axial or radial seal, i.e., located on an end face (in the case of an axial seal) or on a cylindrical surface (in the case of a radial seal). The housing seal can be designed as an O-ring, which is received in a corresponding groove of the base body, or as an injection-molded sealing component. An axial configuration of the housing seal is preferred, with the housing seal particularly preferably surrounding a bayonet fitting that projects in the axial direction. The housing seal can also be designed as a molded seal with a non-circular, particularly longitudinally elongated, cross-section.

[0039] According to a further aspect of the invention, a housing, in particular a battery housing, in particular a traction battery of a motor vehicle, is proposed for receiving battery cells, which has at least one housing wall with a housing opening, wherein the housing opening is closed by a degassing unit, wherein the degassing unit is designed according to one of the preceding claims.

[0040] In particular, the degassing unit is mounted such that it is connected to a wall of the housing by means of at least one fastening element, especially a screw, wherein the fastening element engages with the fastening element area of ​​the base body. The screw connection generates the sealing preload forces necessary for compressing the housing seal. The screw connection can be made, in particular, from inside the electronic housing. Of course, embodiments of the invention also include those in which the degassing unit is screwed to the housing from the outside.

[0041] Finally, the housing wall can have a sealing surface on its outer side, circumferencing the housing opening, against which the housing seal of the degassing unit rests in an assembled state. The sealing surface is preferably designed as a region of the housing wall with minimal deviations in flatness and roughness. Advantageously, the housing, or at least its wall, is made of or consists of a metallic material, so that the sealing surface can be easily achieved with the aforementioned properties through mechanical machining.

[0042] According to a further aspect of the invention, a method for degassing a housing, in particular a battery, in particular a traction battery of a motor vehicle, is proposed with a degassing unit, wherein an actuator is actuated by a control signal of the battery and / or the vehicle and with an emergency degassing pin pierces a membrane which closes a gas passage opening, so that gas escapes through the gas passage opening from the housing.

[0043] The actuator can be activated via a control signal, for example, if the battery control unit signals an impending pressure increase due to a failing cell. Alternatively, the actuator can also be activated via a crash signal, for example, in the event of a vehicle accident. When the actuator is activated, its actuating element, including the emergency venting pin, moves towards the diaphragm so that the tip or at least one cutting edge of the venting pin can pierce or cut through the diaphragm. Due to its tip or at least one cutting edge, the venting pin creates a controlled weakening of the diaphragm, causing it to rupture. This ensures the fastest possible and, in particular, proactive emergency venting function, which is important to guarantee that the housing structure remains intact in the event of a sudden increase in internal pressure within the electronics enclosure.Advantageously, the membrane is actively ruptured, i.e., by the action of the actuator's emergency degassing mandrel on the membrane, regardless of the pressure applied.

[0044] According to a favorable embodiment of the method, after piercing the membrane with the emergency degassing mandrel, the actuator can release a fastening mechanism, in particular a locking mechanism, of a cover hood arranged on an outside.

[0045] Advantageously, the actuator, with its actuating element, can release the fastening mechanism, which can preferably be designed as a snap-fit ​​mechanism for easy installation of the cover. The cover can thus be removed from its normal position, for example, by the pressure of the flowing gas or by being pushed by the actuating element. This allows the fluid path for the escaping gas, which leads through the gas passage opening, to be advantageously enlarged in cross-section. Particularly advantageously, the cover can be lifted off by the actuator, especially by the actuating element, and completely removed from its normal position in the resting state. Brief description of the drawings

[0046] Further advantages become apparent from the following description of the drawings. The drawings illustrate exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations. The following are shown as examples: Fig. 1 an isometric sectional view of a degassing unit according to an embodiment of the invention; Fig. 2 a longitudinal section of the degassing unit according to Fig. 1; Fig. 3 a longitudinal section of the degassing unit according to Fig. 1 with activated actuator and pierced membrane; Fig. 4 an isometric sectional view of the degassing unit according to Fig. 1 with activated actuator; Fig. 5 an isometric sectional view of a degassing unit according to a further embodiment of the invention; Fig. 6 a longitudinal section through the degassing unit according to Fig. 5; Fig. 7 a longitudinal section through the degassing unit according to Fig. 5 with activated actuator and pierced membrane; Fig. 8 an isometric sectional view of the degassing unit according to Fig. 5 with a pierced membrane, wherein the actuator rests against the actuating dome of the cover; Fig. 9 a longitudinal section through the degassing unit according to Fig. 5 with the cover removed; Fig. 10 an isometric sectional view of the degassing unit according to Fig. 5 with the cover removed; Fig. 11 an isometric sectional view of a degassing unit according to a further embodiment of the invention with a cutting edge instead of a tip; and Fig. 12 a longitudinal section through the degassing unit according to Fig. 11 with activated actuator and cut membrane. Embodiments of the invention

[0047] In the figures, identical or similar components are numbered with the same reference symbols. The figures merely show examples and are not to be understood as limiting.

[0048] Fig. Figure 1 shows an isometric sectional view of a degassing unit 10 for a housing 4, in particular a battery, especially a traction battery of a motor vehicle, according to an embodiment of the invention, while in Fig. 2 a longitudinal section of the degassing unit after Fig. 1 is shown.

[0049] The degassing unit 10 has a base body 1 that can be fluid-tightly connected to an edge of a housing opening 44 of the housing 4, with an outer surface 18 and an inner surface 17. The base body 1 has at least one gas passage opening 15, which is closed by a membrane 6 stretched across a surface transversely to an axial direction L. The base body 1 is operatively connected to an actuator 2, which has an emergency degassing pin 19 extending in the axial direction L to the membrane 6. The tip 191 of this pin is designed as the tip of a cylindrical actuating element 21 and is arranged at a predetermined distance from a membrane surface 61, 62 in a rest state. The actuator 2 is located in the Fig. 1 and Fig. 2 illustrated embodiment arranged on the base body 1 and connected to it.

[0050] A cover 5 is arranged on the outer surface 18 of the base body 1. This cover 5 covers the gas passage opening 15 and is connected to the base body 1. The cover 5 is connected to the base body 1 via a fastening mechanism, which here is designed as a snap-fit ​​mechanism 52. The snap-fit ​​mechanism 52 has a snap-fit ​​element 521 in the form of a latch hook arranged on the cover 5. The corresponding snap-fit ​​element 522, which engages with the snap-fit ​​element 521, is arranged on the base body 1.

[0051] In this example, the actuator 2 is located on the inside 17 of the base body 1. Alternatively, the actuator 2 can also be located on an outside of the housing 4.

[0052] The actuator 2 can, for example, be designed as an electrically actuated actuator, in particular as an electromagnetic actuator with a linear magnet or a lifting magnet. The actuating element 21 can, for example, be designed as a linearly movable armature of a lifting magnet system.

[0053] In an alternative embodiment, the actuator 2 can also be designed as a servo motor.

[0054] In this way, the actuator 2 can be configured to directly actuate the actuating element 21. Alternatively, however, it is also possible that the actuator 2 is configured to indirectly actuate the actuating element 21, for example by releasing a preload mechanism. The actuating element 21 can, for example, be preloaded by a spring, the fixation of which is released by the actuator 2.

[0055] For its activation, actuator 2 can, for example, have at least one signal input for a control signal from the battery and / or the vehicle.

[0056] The membrane 6 is arranged on an inner surface 17 of the base body 1 and can, for example, be designed as a gas-impermeable membrane, in particular as a polymer film. The membrane 6 has an outer membrane surface 62 facing the outer surface 18 of the base body 1 and an inner membrane surface 61 facing the inner surface 17.

[0057] However, if the degassing unit 10 is intended to equalize pressure during normal operation due to fluctuations in air pressure or temperature between the interior of the housing and the outside world, it is advantageous if the membrane 6 is designed as a semipermeable membrane, which allows the passage of gaseous media from an environment into the housing 4 and vice versa, and prevents the passage of liquid media and / or solids.

[0058] The base body 1 has at least one fastening element engagement area 11, which is designed for fastening the degassing unit 10 to the housing 4. The degassing unit 10 also has a housing seal 7, which surrounds the gas passage opening 15 of the base body 1 on its inner side 17 and with which the degassing unit 10 can be tightly arranged during assembly on the housing 4.

[0059] The housing 4 has a housing wall 41 with a housing opening 44, as shown in the longitudinal section in Fig. Figure 2 is shown schematically. The housing opening 44 is tightly sealed by the degassing unit 10 during normal operation.

[0060] According to the inventive method for degassing the housing 4, if a high internal pressure in the housing 4 needs to be released to the outside, the actuator 2 is actuated by a control signal from the battery and / or the vehicle. The actuator 2 is activated and moves in the axial direction L towards the diaphragm 6. The direction of movement of the actuator 2 is indicated by an arrow M. The emergency degassing pin 19 of the actuator 2 pierces the diaphragm 6, which closes the gas passage opening 15, allowing gas to escape from the housing 4 through the gas passage opening 15.

[0061] Fig. Figure 3 shows a longitudinal section of the degassing unit 10. Fig. 1 with activated actuator 2 and punctured diaphragm 6. The tip 191 of the emergency degassing mandrel 19 of the actuator 2 has pierced the diaphragm 6. With sufficiently high internal pressure in the housing 4 and a favorable diaphragm property, the diaphragm 6 can burst upon puncture and release the gas passage opening 15 very quickly and across almost its entire cross-section.

[0062] In Fig. Figure 4 shows an isometric sectional view of the degassing unit 10 with a ruptured membrane 6, which is depicted as bent upwards at the edges towards the outer surface 18. With the gas passage opening 15 exposed, the membrane protection grid is visible, which supports the inner membrane surface 61 against pressure from the outer surface 18. The fluid path 8 taken by the escaping gas is also shown. The gas flows through the gas passage opening 15 but is then deflected by the cover 5. The gas flows around its lower edge 54 before it can escape to the outer surface 18.

[0063] Fig. Figure 5 shows an isometric sectional view of a degassing unit 10 according to a further embodiment of the invention, while in Fig. 6 a longitudinal section through the degassing unit 10 after Fig. 5 is shown in the rest state of actuator 2.

[0064] The design of the degassing unit is very similar to that in the Fig. 1, Fig. 2, Fig. 3 to Fig. 4 illustrated embodiment. The actuator 2 also has a cylindrical actuating element 21, which in this example is designed to release the fastening mechanism, which is shown as a locking mechanism 52, and to lift off the cover 5 and to pierce the membrane.

[0065] The cover 5 has an actuating dome 53, which interacts with the actuating element 21 of the actuator 2 when the fastening mechanism of the cover 5 is released. In its rest state, the actuating element 21 is also arranged at a predetermined distance from a base 531 of the actuating dome 53.

[0066] In this embodiment, the emergency degassing pin 19 is arranged on an actuating surface 211 of the actuating element 21 facing the diaphragm 6. The emergency degassing pin 19 with tip 191 is smaller and is partially recessed into the end face of the actuating element 21, which is designed as an actuating surface 211.

[0067] The base 531 of the actuating dome 53 has a receiving area 532 for the emergency degassing pin 19, so that the actuating surface 211 of the actuating element 21 rests flat against the base 531 of the actuating dome 53 when actuated, and the tip 191 of the emergency degassing pin 19 is received by the receiving area 532. The base 531 of the actuating dome 53 has a recess to serve as the receiving area 532 for the tip 191.

[0068] According to the inventive method for degassing the housing 4, if a high internal pressure in the housing 4 needs to be vented to the outside, the actuator 2 is actuated by a control signal from the battery and / or the vehicle. The actuator 2 is activated and moves in the axial direction L towards the diaphragm 6. The direction of movement of the actuator 2 is indicated by an arrow M. The emergency degassing pin 19 of the actuator 2 pierces the diaphragm 6, which closes the gas passage opening 15, and can then contact the flat base 531 of the actuating dome 53 of the cover 5 with its actuating surface 211.

[0069] Fig. Figure 7 shows a longitudinal section through the degassing unit 10 with a pierced membrane 6. Fig. Figure 8 shows an isometric sectional view of the degassing unit 10 with a punctured diaphragm 6, the actuator resting against the actuating dome 53 of the cover 5. The diaphragm 6 is arched upwards by the movement of the actuating element 21 and clamped between the actuating element 21 and the base 531 of the actuating dome 53. In the area of ​​the receiving area 532, the diaphragm 6 has a puncture opening 63, which was created by the perforation of the diaphragm 6 with the tip 191 of the emergency degassing mandrel 19. The puncture opening 63 can subsequently cause the diaphragm 6 to burst under increasing pressure.

[0070] With further movement of the actuating element 21 of the actuator 2, the actuating dome 53 is pressed further in the axial direction L until, after the emergency degassing pin 19 pierces the diaphragm 6, the fastening mechanism of the cover 5, designed as a latching mechanism 52, is released. The cover 5 can then be folded away or even completely lifted off.

[0071] Fig. Figure 9 shows a longitudinal section through the degassing unit 10 with the ruptured membrane 6 and the cover removed, while in Fig. Figure 10 shows an isometric sectional view of the degassing unit 10 in this state. The fluid path 8 for the outgoing gas is shown with dashed arrows. It can be seen that with the cover lifted, the gas can flow freely through the gas passage opening 15 onto the outside 18. The base body 1 has a central opening 152 for this purpose.

[0072] Fig. Figure 11 shows an isometric sectional view of a degassing unit 10 according to a further embodiment of the invention with at least one cutting edge 192 instead of a tip 191. Fig. Figure 12 shows a longitudinal section through the degassing unit 10. Fig. 11 with activated actuator 2 and cut membrane 6.

[0073] The degassing unit 10 has a base body 1 that can be fluid-tightly connected to an edge of a housing opening 44 of the housing 4, with an outer surface 18 and an inner surface 17. The base body 1 has at least one gas passage opening 15, which is closed by a membrane 6 stretched across a surface transversely to an axial direction L. The base body 1 is operatively connected to an actuator 2, which has an emergency degassing mandrel 19 extending in the axial direction L to the membrane 6. The cutting edge 192 of this mandrel is arranged on the end face of a cylindrical actuating element 21 and, in a rest state, is spaced at a predetermined distance from a membrane surface 62. The actuator 2 can be operated as in the case described in Fig. 1 and Fig. 2 illustrated embodiment arranged on the base body 1 and connected to it.

[0074] The actuating element 21 has a preferably circumferential cutting edge 192 on the surface of the emergency degassing mandrel 19 facing the diaphragm 6. This cutting edge has a diameter slightly larger than the diameter of the base 531 of the actuating dome 53. The cutting edge 192 thus engages the base 531 of the actuating dome 53 at its outer edge. When the actuator 2 is actuated, the diaphragm 6 is arched upwards by the movement of the actuating element 21, clamped between the actuating element 21 and the base 531 of the actuating dome 53, and cut through when the actuating element 21 and the base 531 of the actuating dome 53 come together. This creates an opening in the diaphragm 6 for emergency degassing of the housing 4.

[0075] Regarding the other characteristics of the in Fig. 11 and Fig. The degassing unit 10 shown in 12 refers to the description in Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9 to Fig.Reference is made to the exemplary embodiment shown in section 10. Reference sign 10 Degassing unit 1 Basic body 11. Area of ​​influence of fasteners 15 Gas passage opening 151 Edge of the gas passage opening 152 central opening 16 sealing grooves of the base body 17 Inside of the base body 18 Outer surface of the base body 19 Emergency degassing spike 191 Tip of the emergency degassing mandrel 192 Cutting edge of the emergency degassing dome 2 Actuator 21 Actuating element 211 Operating area 3 Membrane support device 4 cases 41 Housing wall 44 Housing opening 5 Cover 51 ventilation openings 52 Locking mechanism 521 Latching element 522 Latching counter element 53 Actuator Dome 531 Floor 532 Recording area 54 Rand 6 Membran 61 Outer membrane surface 62 Inner membrane surface 63 Penetration opening 64 Membrane protection grilles 7 Housing seal 8 Fluid path L Axial direction M Direction of movement actuator

Claims

[1] Degassing unit (10) for a housing (4), with a base body (1) which can be connected in a fluid-tight manner to an edge of a housing opening (44) of the housing (4), with an outer surface (18) and an inner surface (17), and which has at least one gas passage opening (15) which is closed with a membrane (6) stretched across a surface transverse to an axial direction (L), wherein the base body (1) is operatively connected to an actuator (2) which has an emergency degassing mandrel (19) extending in the axial direction (L) to the membrane (6) and whose tip (191) or at least a cutting edge (192) is arranged at a predetermined distance from a membrane surface (61, 62) in a rest state, wherein the emergency degassing mandrel (19) is movable towards the membrane when the actuator (2) is activated, so that the tip (191) or cutting edge (192) can pierce or cut the membrane (6), wherein the actuator (2) is arranged on the base body (1) or can be arranged on the housing (4), characterized by , that a cover (5) is arranged on the outside (18) of the base body (1), which covers the gas passage opening (15) and which is connected to the base body (1) via a fastening mechanism, wherein the actuator (2) has an actuating element (21) which is designed to release the fastening mechanism. [2] Degassing unit according to claim 1, characterized by , that the cover (5) has an actuating dome (53) which is designed to interact with the actuating element (21) of the actuator (2) to release the fastening mechanism of the cover (5), wherein the actuating element (21) is arranged at a predetermined distance from a base (531) of the actuating dome (53) in a rest state. [3] Degassing unit according to any of the preceding claims, characterized bythat the actuator (2) is arranged on the inside (17) of the base body (1) or on an outside or inside of the housing (4). [4] Degassing unit according to any of the preceding claims, characterized by , that the emergency degassing pin (19) is arranged on an actuating surface (211) of the actuating element (21) facing the diaphragm (6). [5] Degassing unit according to claim 2, characterized by , that the base (531) of the actuating dome (53) has a receiving area (532) for the emergency degassing mandrel (19), so that the actuating surface (211) of the actuating element (21) lies flat against the base (531) of the actuating dome (53) in the case of actuation and the tip (191) or the at least one cutting edge (192) of the emergency degassing mandrel (19) is received by the receiving area (532). [6] Degassing unit according to any one of the preceding claims, characterized by, that the actuator (2) is designed as an electrically actuated actuator, in particular as an electromagnetic actuator. [7] Degassing unit according to any one of the preceding claims, characterized by , that the actuator (2) is designed to directly actuate the actuating element (21), or that the actuator (2) is designed to indirectly actuate the actuating element (21), in particular by releasing a preload mechanism. [8] Degassing unit according to any of the preceding claims, characterized by that the actuator (2) has at least one signal input for a control signal of the battery and / or the vehicle. [9] Degassing unit according to any of the preceding claims, characterized by , that the membrane (6) is arranged on an inner side (17) of the base body (1). [10] Degassing unit according to any one of the preceding claims, characterized by , that the membrane (6) is designed as a gas-impermeable membrane, in particular as a polymer film. [11] Degassing unit according to any one of claims 1 to 9, characterized by , that the membrane (6) is designed as a semipermeable membrane which allows the passage of gaseous media from an environment into the housing (4) and vice versa, and prevents the passage of liquid media and / or solids. [12] Degassing unit according to any of the preceding claims, characterized by , that the base body (1) has at least one fastening element action area (11) which is designed to fasten the degassing unit (10) to the housing (4). [13] Degassing unit according to any of the preceding claims, characterized by , that 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). [14] Housing (4) for receiving battery cells, which has at least one housing wall (41) with a housing opening (44), wherein the housing opening (44) is closed by a degassing unit (10), wherein the degassing unit (10) is designed according to one of the preceding claims. [15] Method for degassing a housing (4) of a battery, comprising a degassing unit (10) according to any one of claims 1 to 13, wherein an actuator (2) is actuated by a control signal from the battery and / or a vehicle and pierces a membrane (6) with an emergency degassing pin (19), which closes a gas passage opening (15), so that gas escapes from the housing (4) through the gas passage opening (15), wherein, after piercing the membrane (6) with the emergency degassing pin (19), the actuator (2) releases a fastening mechanism of a cover (5) arranged on an outer surface (18).

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