DE102021120073A1 - Motor vehicle with a battery arrangement and method for dropping a battery unit from a motor vehicle - Google Patents

Abstract

The invention relates to a motor vehicle (10) with a battery arrangement (12), which has at least one first battery unit (14, 14a) with at least one first battery cell, a detection device (34, 34a) which is designed to detect a specific critical state at least to detect at least one first battery cell, and has a release device (32, 40, 40a, 40b, 40c), which is designed to, in the event of a detection of the specific critical state of at least the first battery cell, the first battery unit (14, 14a) with respect to a Drop vehicle vertical axis directed at least partially downwards from the motor vehicle (10). The battery arrangement (12) has at least one second battery unit (14) with at least one second battery cell, the release device (32, 40, 40a, 40b, 40c) being designed for this purpose, at least in the event that the specific critical state of the at least one first battery cell, and is not detected for the at least one second battery cell, to drop the first battery unit (14, 14a) independently of the second battery unit (14).

Description

The invention relates to a motor vehicle with a battery arrangement which has a battery unit with at least one battery cell, a detection device and a release device, the detection device being designed to detect a specific critical state of the at least one battery cell and the release device being designed to do so in the event of after detection of the specific critical state, to eject the battery unit downwards from the motor vehicle with respect to a vehicle vertical axis. Furthermore, the invention also relates to a method for dropping a battery unit from a motor vehicle.

Various dropping options for dropping a battery from a motor vehicle are known from the prior art. For example, describes the DE 20 2017 001 021 U1 an active underbody battery tray, whereby the battery tray floor, including the battery block mounted on it, tilts sideways using electromechanical unlocking bolts or can also be completely thrown off depending on the situation. Crash sensors are used to decide on which side the battery tray floor should tip or whether it should be completely ejected.

The CN 109895720A describes a method according to which, upon detection of an imminent collision of the motor vehicle, the battery of the motor vehicle can be ejected before the collision in order to protect the battery.

The CN 111703305A describes the possibility of accommodating different battery packs in separate cabins and, depending on the temperature of the respective battery packs, these can be ejected 2 meters to the side of the vehicle using an elastic spring in the battery cabin.

The WO 2020/247704 A1 describes a method according to which a temperature of a battery can be sensed and it is determined whether the sensed temperature is greater than a predetermined temperature limit and if so the battery can be ejected from a power supply assembly.

A great deal of effort is currently being put into protecting the occupants and infrastructure in the event of a battery fire in a battery of a motor vehicle, in particular a high-voltage battery. This includes, for example, fire protection measures, extinguishing devices, fire blankets and decay containers for an entire vehicle. If there is no way to eject the battery from the vehicle, the vehicle will always be totaled in the event of a battery fire. If the high-voltage battery is firmly bolted to the vehicle, this means that in the event of a battery fire, the entire vehicle will be immediately affected by the fire. A high-voltage battery has an enormous amount of energy and energy density, which means a great potential danger for the occupants.

Although the possibility of dropping a battery from a motor vehicle is known in principle, the solutions proposed so far lead to further problems. For example, if individual battery packs are ejected from the side, this poses a massive threat to the environment. A downward ejection leads to a reduced environmental hazard potential, but precisely in the case of a high-voltage battery, which is typically very large, the following traffic can also be endangered if the battery is ejected downwards.

The object of the present invention is therefore to provide a motor vehicle and a method that make it possible to increase safety in the event of a battery defect, in particular a high-voltage battery, of the motor vehicle both in relation to the motor vehicle itself and in relation to the environment to increase as possible. It is also the object of advantageous developments of the invention to provide a drop option for a battery unit of the motor vehicle that can be implemented as simply and efficiently as possible and that does not impair the protective effect for the battery during normal operation of the motor vehicle and the battery.

This object is achieved by a motor vehicle and a method having the features of the independent patent claims. Advantageous configurations of the invention are the subject matter of the dependent patent claims, the description and the figures.

A motor vehicle according to the invention has a battery arrangement which in turn comprises at least one first battery unit with at least one first battery cell, a detection device which is designed to detect a specific critical state of at least the at least one first battery cell and a release device which is designed to in the event of a detection of the specific critical state, at least the first battery unit must be ejected from the motor vehicle at least in part in a downward direction relative to a vertical axis of the vehicle. The battery arrangement further includes at least one second battery unit with at least one second battery cell, wherein the ejection device is designed, at least in the event that the Certain critical state of the at least one first battery cell, and not detected for the at least one second battery cell, to eject the first battery unit independently of the second battery unit.

If a critical state of a battery cell of the first battery unit is detected while no critical state of a battery cell of the second battery unit is detected, the first battery unit can be thrown down from the motor vehicle while the second battery unit remains on the motor vehicle. As a result, the safety in relation to the motor vehicle as well as in relation to the environment can be increased in many respects: On the one hand, the battery unit in question, which is referred to here as the first battery unit that has a defect, is at the bottom and not to the side of the motor vehicle dropped. The dropping direction can also be directed obliquely downwards and does not have to run parallel to a vertical line and/or to the vertical axis of the vehicle. The first battery unit can, for example, also slide down at an angle over an opening flap, which then simultaneously represents a discharge ramp. Preferably, however, a vertical component of the ejection direction is at least as large or larger, for example by a multiple, than a horizontal component of the ejection direction, particularly in the case in which the vehicle is positioned such that the vehicle's vertical axis is aligned parallel to the vertical. However, the dropping direction can optionally have an exclusively vertical component or be directed parallel to the vertical and/or to the vertical axis of the vehicle. In addition, it is preferred that the at least one first battery unit is ejected from an underbody area of the motor vehicle. This can significantly increase security, especially with regard to pedestrians, built-up areas or the like. In the case of a downward ejection, it is guaranteed, at least in most cases, that the ejected battery unit also lands on a road that is typically non-flammable. Since, in addition, in the event of a detected defect, namely the specific critical state of the at least one first battery cell, the entire battery arrangement is not discarded, but only the affected battery unit, safety for the following traffic can also be significantly increased, because this is not enormously large discarded battery, but only with a much smaller battery unit. In principle, this can be configured as small as desired. It is also conceivable, for example, that such a battery unit is only provided by a single battery cell. In other words, the invention also enables only individual battery cells of a high-voltage battery to be discarded if a critical state for the battery cell was detected by the detection device. As a result, the risk of accidents caused by such a drop can be reduced to a minimum. Safety with regard to the discarding motor vehicle can also advantageously be increased. This is due to the fact that the motor vehicle still remains drivable, since not all battery units are generally discarded, since they are usually not all defective at the same time. If a battery cell becomes defective, this typically only affects one battery unit. In the event of a thermal runaway of this battery cell, this thermal propagation initially spreads from the affected battery cell to its immediate vicinity. By discarding the first battery unit, it is thus advantageously possible to keep such thermal propagation away from other battery units that have not yet been affected, and which can then continue to be used to operate the motor vehicle. In addition, thermal propagation of a battery cell or the start thereof can be detected very reliably and early, for example if the temperature of a battery cell exceeds a specific threshold value, which is preferably between 60°C and 100°C, for example 70°C or 80°C . The fact that even if the first battery unit is discarded, the motor vehicle can continue to be operated by the at least one remaining second battery unit also has the advantage that the first battery unit can still be discarded even when the motor vehicle is stationary. This makes it possible, for example, even when the vehicle is parked, to start it automatically in the case of dropping and to move it away at least a little from the dropping point, in particular automatically. If a battery cell begins to thermally run away and is detected in good time, the motor vehicle can first be guided to a safe location where it is less problematic to drop it. As a result, the safety for the environment can also be increased at the same time.

The battery arrangement can be a high-voltage battery, for example. This can generally have numerous battery cells, for example lithium-ion cells. Furthermore, these battery cells are grouped into the at least one first battery unit and the second battery unit. The battery arrangement can also have numerous other battery units. A respective battery unit can be provided by a single battery cell or by a battery module with multiple battery cells. However, a battery unit can also include a number of battery modules, which in turn have a number of battery cells. The detection device may have at least one sensor to the to detect a certain critical state of the at least one first battery cell, as well as a corresponding critical state of other battery cells of the battery array. The at least one sensor is preferably designed as at least one temperature sensor. The detection device preferably includes a number of temperature sensors, which can also be assigned to respective battery units, for example. In particular, at least one temperature sensor can be provided for each battery unit. In addition, the detection device can also have other sensors, for example a pressure sensor, gas sensor and/or a voltmeter for measuring the voltage of the battery cells and/or battery units. The at least one critical state is preferably detected when the temperature of at least the first battery cell or, in general, of a battery cell of the first battery unit exceeds a predetermined limit value, for example the threshold value already described above. In general, several such limit values can also be specified, for example a first limit value, for example 60°C, from which release preparations are already made, for example the driver is informed and asked to drive to a safe place, and a second limit value, for example Example 70°C or 80°C, from which the ejection of the first battery unit is triggered. The second limit value is greater than the first limit value.

According to the invention, the first battery unit is ejected in relation to the vertical axis of the vehicle, at least in part downwards. It would also be advantageous if the battery units were protected as well as possible from environmental influences and possible intrusions from below during normal operation of the motor vehicle. In order to accomplish this, the motor vehicle can have an underride guard. In order to nevertheless provide an advantageous release mechanism, the procedure can be as follows: It represents a further advantageous embodiment of the invention if the battery arrangement comprises a battery housing, with at least the first battery unit being arranged in the battery housing, which comprises a housing base which comprises at least the delimits the first battery unit downwards from the area surrounding the motor vehicle, the ejection device for ejecting the first battery unit being designed to open at least one first base part of the housing base assigned to the first battery unit, in particular so that a first housing base opening assigned only to the first battery unit is provided and the first battery pack is ejected and the first battery pack falls through its associated housing base opening, at least in part due to the force of gravity. In other words, separate housing base openings can be provided in the housing base for the respective battery units, which are closed by respective base parts of the housing base during normal operation. For example, the bottom parts can be opened in the manner of flaps or in some other way, as will be explained in more detail later. It is therefore advantageously possible on the one hand to nevertheless provide a protective mechanism for the battery units against environmental influences downwards, which is provided here by the housing base of the battery housing, and nevertheless to create an advantageous possibility of dropping the respective battery units through the housing base. The bottom of the housing can include or represent the underrun protection already mentioned above. In general, the housing base can be made in several parts and can include, for example, a compartment base of a compartment of the housing in which one of the battery units is arranged, as well as an additional underrun protection arranged on the underside. However, the housing base can also be designed in one piece, for example as a housing base, which then correspondingly takes on both the function of such an underrun protection and of a compartment base. In addition, crash structures can also be integrated into the housing base, for example a corrugated metal sheet, so that energy can be absorbed by such structures when objects hit the housing base from below, in particular by deformation of these crash structures. The at least one first battery unit can be ejected when the housing bottom opening assigned to it is released solely as a result of shear forces or only partially as a result of gravity, i.e. to initiate the ejection, an at least partially or completely downward-pointing force can be applied by an ejection device, e.g. mechanically, to which at least one first battery unit is attached, in order to achieve a mechanical "ejection", e.g. via a mechanically extendable slide or a prestressed spring or the like. Ejection by means of a slide or spring or another ejection device, which in general can be designed not only mechanically but also electrically, electromechanically, magnetically, electromagnetically, etc., would also be favored by gravity, and the module or the The battery unit can be transported out of the rest of the battery even more safely and reliably thanks to the additionally provided ejection force.

According to a further very advantageous embodiment of the invention, the first base part is opposite the housing part in which the first battery unit is located when it is not ejected is taken, sealed. For example, a seal, for example a sealing ring, can be arranged between the first base part and the compartment walls on which the first base part is arranged in the closed state and which are assigned to a first compartment in which the first battery unit is accommodated. In the closed state, such a compartment thus represents a chamber in which the relevant battery unit is arranged. This can also apply in the same way to all other battery units, associated compartments and corresponding base parts.

The battery housing can therefore have appropriate compartments for the individual battery units. In general, the battery housing can provide receiving areas, as is provided according to a further advantageous embodiment of the invention. Correspondingly, according to this configuration, the battery arrangement has a plurality of battery units comprising the at least one first and second battery unit, with each battery unit having at least one battery cell, and the battery housing having a plurality of receiving areas which are separated from one another in particular by partitions and in which the battery units are arranged . In this case, the housing base has a plurality of base parts assigned to the respective battery units, with the ejection device being designed to open the respective base parts independently of one another. Thus, if a corresponding battery unit is to be ejected, the associated base part of the housing base can be opened. The battery unit then automatically falls out of its receiving area. Any electrical lines to the battery unit can preferably be designed in such a way that they tear off on their own as a result of being thrown off. In order to prevent an uncontrolled tearing off, the lines can also include appropriate predetermined tearing points or be realized with plug connections or the like, which are automatically opened by the ejection, in particular due to the tensile force of the ejected battery unit.

By providing separate receiving areas or receiving chambers specifically assigned to the individual battery units, in particular by partition walls, i.e. the above-mentioned compartment walls, it can be ensured that if one battery unit is ejected, all the other battery units are nevertheless reliably held in position. In addition, the separation of the battery units by partition walls enables better spatial and thermal insulation, which in turn has advantages in terms of preventing thermal propagation from spreading. The protective effect can also be better implemented through the separation from the environment for the remaining battery units that have not been ejected, since these are then still located in their respective sealed compartments, even if one of the base parts was opened to eject the battery unit in question. Nevertheless, it would also be conceivable to provide receiving areas for the respective battery units which are not spatially separated from one another by respective partition walls. Even then, it is possible, in particular through the bottom openings in the housing bottom that are specifically assigned to the respective battery units, to manage the ejection of a defective battery unit independently of the other battery units, in that only the housing bottom opening of the associated housing bottom part that is assigned to this battery unit is provided.

In general, not only the first battery unit can be ejected independently of the other battery units, but generally also each of the other battery units of the battery arrangement in a corresponding manner if a defect in a battery cell comprised by this battery unit in question is detected, in particular by means of the detection device. Correspondingly, the detection device is preferably also designed to detect the specific critical state of the at least one second battery cell, with the ejection device being designed to, in the event of a detection of the specific critical state of the at least one second battery cell, the second battery unit with respect to the vertical axis of the motor vehicle jettison at least partially downwards from the motor vehicle, in particular independently of the first battery unit and in particular also independently of the other battery units. Of course, it is also conceivable that several battery units are ejected at the same time, for example if a critical state has been detected for several battery cells that are assigned to different battery units. In other words, it is preferred that each battery unit that includes a battery cell for which the detection device has detected a critical state is ejected accordingly, as already described for the first battery unit.

In a further, very advantageous embodiment of the invention, at least the first base part is designed as a flap, with the ejection device being designed to open the flap in order to eject the first battery unit. Alternatively, the first base part can also be decoupled as a whole from the battery housing in order to drop the first battery unit by means of the dropping device be educated. In both cases, it can advantageously be accomplished to reliably eject the associated battery unit. When the base part is designed as a flap, the advantage can also be achieved that the flap itself is prevented from being thrown off. One component less falls on the road. The additional ejection of this flap or the ejection of the base part as a whole has the advantage that the base part does not collide with the battery unit that was ejected when the battery unit is ejected, depending on the current direction of travel of the motor vehicle. This is particularly advantageous when the battery unit is ejected when the motor vehicle is stationary, since it allows the motor vehicle to be driven away from the ejection point in any direction of travel without an open flap hanging down colliding with the battery unit that was ejected or colliding with it Keeps hanging.

In a further advantageous refinement of the invention, the battery units are each provided by only the single battery cell they comprise, or a respective battery unit represents a battery module which comprises a plurality of the at least one battery cell. The first variant has the advantage that even just individual battery cells can advantageously be ejected in this way. The damage can thus be reduced to a minimum. In contrast, the ejection of an entire battery module with several battery cells has the advantage that this greatly simplifies the ejection concept and in particular the design of the housing base. At the same time, depending on the design of the module size, battery modules can be dropped in a very differentiated manner, so that the damage that occurs can also be kept within extremely low limits as a result. A battery module then comprises, for example, at least two battery cells, preferably at least five battery cells, particularly preferably at least ten battery cells. However, a battery unit can also be designed in such a way that it includes a number of battery modules with a number of battery cells. If a critical state is detected for one of these battery cells of one of these battery modules comprised by the relevant battery unit, the entire battery unit is ejected accordingly, including all battery modules that are not affected. This also makes it possible, for example, to divide the battery, in particular the high-voltage battery, into only two battery units, for example.

In a further advantageous embodiment of the invention, the ejection device is designed to check, if the specific critical state of the at least one first battery cell is detected, to check whether at least one first ejection safety condition is met and to only eject the at least one first battery unit if the first release safety condition is met. For example, as soon as a critical state of at least one battery cell is detected, provision can be made for the motor vehicle to first check whether the motor vehicle is currently in a sufficiently safe location for the battery unit in question to be ejected. Such a check can be carried out, for example, using navigation data and/or on the basis of data provided by an environment sensor system of the motor vehicle. For example, the vehicle can be designed to determine its location using a navigation map depending on its current GPS coordinates. Depending on the current location, the motor vehicle, for example the vehicle electronics, can also use the navigation system to suggest a route that is less frequented, for example a side street or a dirt road, and is therefore better suited for dropping. During the dropping process, the vehicle’s surroundings sensors could scan the area for endangered people, facilities, other vehicles, cyclists, etc. and accordingly temporarily prohibit dropping until the dropping safety condition is met, for example that there is currently a certain area around the motor vehicle there are no other road users. As already mentioned above, a critical state of the at least one battery cell can be determined, for example, based on its temperature. As soon as a battery cell exceeds a critical temperature, for example between 80 and 100°C, thermal propagation or a battery fire can no longer be stopped. In such an early stage of the fire, however, there would still be enough time to drive to a safe drop location and disconnect the battery or the battery unit. Thus, there is sufficient time to wait until the release safety condition is met. In addition, the motor vehicle can also actively take measures itself, such as issuing instructions to the driver, or also, in order to actively bring about such dropping safety conditions or their fulfillment, drive to a safe dropping location as part of autonomous driving.

In addition, the motor vehicle can also be designed to take additional safety measures when a battery unit is to be ejected. For example, the hazard warning lights can be activated automatically to warn surrounding road users at an early stage. The shedding of the battery unit can also be coupled directly with an emergency call, for example to alert the fire brigade immediately.

In a further advantageous embodiment of the invention, the motor vehicle is designed to continue to move actively even when the first battery unit has been ejected, with an energy supply for operating the motor vehicle being able to be provided by the at least one second battery unit. This advantageously makes it possible to move away from the dropping point again. Moving away from the dropping point can, for example, also be carried out automatically by the motor vehicle, which is very advantageous, for example, if the motor vehicle is not currently being driven during the dropping and is parked, for example. In addition, this also enables the driver of the vehicle and the occupants to get to safety.

Precisely in order to enable the vehicle to be safely moved away from the dropping point when driving autonomously, it represents a further, very advantageous embodiment of the invention if the motor vehicle has at least one surroundings sensor for detecting at least part of the surroundings of the motor vehicle, wherein the motor vehicle is designed to move away automatically or at least partially automatically from a drop point at which the first battery unit was dropped, depending on the at least one part of the environment detected by the at least one surroundings sensor. As a result, among other things, the motor vehicle can be moved away completely automatically, ie without the user having to do anything, and at the same time adequate safety can be ensured for the surrounding area. Moving away does not necessarily have to be very far, just a few meters, for example at least 5 or 10 m, are already sufficient to largely rule out a potential risk to the motor vehicle from the ejected battery unit. The at least one environment sensor can be part of an environment sensor system already mentioned above, or the environment sensor system described above can also be provided by this at least one environment sensor. Such an environment sensor can be, for example, a camera, an ultrasonic sensor, a radar and/or lidar. Any combinations of these surroundings sensors are also conceivable. Sensors that are typically already present on a motor vehicle anyway can also be used for this purpose, such as parking sensors and/or an anti-theft camera or the like.

It is also conceivable that, if a critical battery cell or its critical state is detected, the motor vehicle is designed to switch to a remote control mode in which the motor vehicle can also be remotely controlled by a user outside the motor vehicle, for example via an app on their mobile communication device. The user can be informed about such a critical state and the planned dropping, for example via his mobile communication device from the motor vehicle. After the battery unit has been ejected, the user can also remotely move his motor vehicle outside the motor vehicle away from the ejection point and, for example, park it in a safe place. However, it is also conceivable to move the vehicle to a safe dropping point by remote control. This advantageously allows the user to leave his vehicle for safety reasons even before it is dropped.

In a further advantageous embodiment of the invention, at least the first base part is arranged with at least one fastening device on the battery housing, with the ejection device having a fastening release unit which is designed to release the at least one fastening device in order to open at least the first base part, in particular with the fastening release unit having a has a blasting unit, which is designed to blast the at least one fastening device, and/or the fastening release unit has a shearing unit, which is designed to cut through the at least one fastening device designed as a screw or pin, and/or the fastening device as a bolt or Pin is formed with a through hole through which a retaining pin is passed, wherein the fastener release unit is adapted to remove the retaining pin from the through hole, and / or the fasteners direction is designed as a screw device, wherein the fastening release unit is designed to unscrew the screw device upwards at least from the first floor part.

So there are numerous possibilities provided, for example, to remove the base part only on one side in the form of a flap or on all sides to detach it as a whole from the rest of the battery housing by means of the fastening detachment unit. It is advantageous if the bottom of the housing is attached to the rest of the battery housing by means of screws, pins or bolts. These screws, bolts or even pins can be loosened in a simple and efficient manner by means of the fastening release units described. Provision is also made for the fastening devices to be released to be released as simultaneously as possible by means of the fastening release unit. This is advantageous for a smooth unfolding or dropping of the bottom part. This again shows the great advantage compared to dropping an entire battery, since there are significantly fewer fastening devices to drop a smaller battery unit are to be solved synchronously in time, which can be done much more easily and reliably.

In addition, the battery arrangement is preferably designed such that as soon as the floor opening associated with the relevant battery unit is cleared by opening the associated floor part, the battery unit falls out of the motor vehicle due to the force of gravity. The battery unit is not otherwise attached to the motor vehicle, so that only the at least one attachment device, via which the first base part is attached to the battery housing or to the other component of the battery arrangement, has to be released in order to eject the battery unit. Optionally, an additional ejection device can also be provided in order to promote the ejection by applying additional force to the battery unit.

The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus or motorcycle.

Furthermore, the invention also relates to a method for dropping a first battery unit with at least one first battery cell from a motor vehicle, the first battery unit being directed at least partially downwards from the motor vehicle with respect to a vertical axis of the vehicle, at least in the event that a specific critical state of at least the first battery cell is detected is dropped. At least in the event that the specific critical state of the at least one first battery cell is detected and not detected for at least one second battery cell of a second battery unit of the motor vehicle, the first battery unit is discarded independently of the second battery unit. In other words, in this case the second battery unit is not ejected, only the first battery unit.

The advantages described for the motor vehicle according to the invention and its configurations apply in the same way to the method according to the invention.

The invention also includes developments of the method according to the invention, which have features as have already been described in connection with the developments of the motor vehicle according to the invention. For this reason, the corresponding developments of the method according to the invention are not described again here.

The invention also includes the combinations of features of the described embodiments. The invention also includes implementations that each have a combination of the features of several of the described embodiments, unless the embodiments were described as mutually exclusive.

• 1 eine schematische Darstellung eines Kraftfahrzeugs mit einer Batterieanordnung und einer Abwurfeinrichtung zum selektiven Abwerfen von Batterieeinheiten gemäß einem Ausführungsbeispiel der Erfindung;
• 2 eine schematische Detailansicht des Abwurfs einer Batterieeinheit aus einer Batterieanordnung gemäß 1 gemäß einem Ausführungsbeispiel der Erfindung;
• 3 eine schematische Darstellung einer in einem Kompartment des Batteriegehäuses aufgenommenen Batterieeinheit bei geschlossenem Kompartmentboden gemäß einem Ausführungsbeispiel der Erfindung;
• 4 eine schematische Darstellung der Batterieanordnung aus 3 bei sich öffnendem Kompartmentboden, welcher als Ganzes abgeworfen wird, gemäß einem Ausführungsbeispiel der Erfindung;
• 5 eine schematische Darstellung der Batterieanordnung mit aufklappendem Kompartmentboden gemäß einem weiteren Ausführungsbeispiel der Erfindung;
• 6 eine schematische Darstellung einer Batterieanordnung mit mehreren in einem Kompartment aufgenommenen Batterieuntereinheiten gemäß einem weiteren Ausführungsbeispiel der Erfindung;
• 7 eine schematische Darstellung einer Befestigungseinrichtung zum Befestigen des Kompartmentbodens und einer Befestigungslöseeinheit zum Lösen der Befestigungseinrichtung gemäß einem ersten Ausführungsbeispiel der Erfindung,
• 8 eine schematische Darstellung einer Befestigungseinheit zur Befestigung des Kompartmentbodens und einer Befestigungslöseeinheit zum Lösen der Befestigungseinrichtung gemäß einem weiteren Ausführungsbeispiel der Erfindung; und
• 9 eine schematische Darstellung einer Befestigungseinrichtung zum Befestigen des Kompartmentbodens und einer Befestigungslöseeinheit zum Lösen der Befestigungseinrichtung gemäß einem weiteren Ausführungsbeispiel der Erfindung.

Exemplary embodiments of the invention are described below. For this shows:

• 1 a schematic representation of a motor vehicle with a battery arrangement and a release device for the selective release of battery units according to an embodiment of the invention;
• 2 a schematic detailed view of the dropping of a battery unit from a battery arrangement according to FIG 1 according to an embodiment of the invention;
• 3 a schematic representation of a battery unit accommodated in a compartment of the battery housing with the compartment floor closed according to an exemplary embodiment of the invention;
• 4 a schematic representation of the battery arrangement 3 with the compartment floor opening, which is ejected as a whole, according to an exemplary embodiment of the invention;
• 5 a schematic representation of the battery assembly with hinged compartment floor according to a further embodiment of the invention;
• 6 a schematic representation of a battery arrangement with a plurality of battery subunits accommodated in a compartment according to a further exemplary embodiment of the invention;
• 7 a schematic representation of a fastening device for fastening the compartment floor and a fastening release unit for releasing the fastening device according to a first exemplary embodiment of the invention,
• 8th a schematic representation of a fastening unit for fastening the compartment floor and a fastening release unit for releasing the fastening device according to a further exemplary embodiment of the invention; and
• 9 a schematic representation of a fastening device for fastening the compartment floor and a fastening release unit for releasing the fastening device device according to a further embodiment of the invention.

The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention that are to be considered independently of one another and that each also develop the invention independently of one another. Therefore, the disclosure is also intended to encompass combinations of the features of the embodiments other than those illustrated. Furthermore, the described embodiments can also be supplemented by further features of the invention that have already been described.

In the figures, the same reference symbols designate elements with the same function.

1 shows a schematic representation of a motor vehicle 10 with a battery arrangement 12 according to an exemplary embodiment of the invention. In the present example, the battery arrangement 12 is therefore configured as a high-voltage battery. In this case, the battery arrangement 12 has a plurality of battery units 14 . A respective battery unit can in turn include a number of individual battery cells, for example lithium-ion cells. In principle, however, the individual battery units 14 can also be individual battery cells. In this example, the battery units 14 are arranged next to one another in the longitudinal direction of the vehicle, which corresponds to the x-direction shown here. In addition, battery units 14 can also optionally be arranged next to one another in the y-direction, which runs parallel to the transverse direction of the vehicle. Alternatively, the battery units 14 shown here can extend over a large part of the width of the motor vehicle in the y-direction. In other words, in this example, no multiple battery units 14 are arranged next to one another in the y-direction. There are basically no limits to the arrangement and design of the size of the battery units 14 .

Furthermore, the battery arrangement 12 has a battery housing 16 . This battery housing 16 comprises a housing base 18. This housing base 18 separates the respective battery units 14 from the surroundings 20 of the motor vehicle 10 on the underside 10 bottom bounding floor. The designations “above” and “below” refer in particular to the course of a motor vehicle vertical axis, which is parallel to the z-direction shown here. The z-direction shown here therefore points upwards. In addition, the battery housing 16 provides an associated receiving area 24 for the respective battery units 14 . This receiving area 24 is also referred to as compartment 24 below. The individual receiving areas 24 are separated from one another by respective side or partition walls 26, with 1 for reasons of clarity, only some of these partitions 26 are provided with a reference number. Furthermore, the housing base 18 comprises base parts 28 assigned to the individual battery units 14, of which 1 only some are provided with a reference number for reasons of clarity. These are described in more detail below.

Furthermore, the battery arrangement 12 also includes a control device 30. This can simultaneously act both as a detection device 34 for detecting a critical state of at least one of the battery cells of the battery units 14 and as a release device controller 32 for controlling the release of individual or multiple battery units 14. For the detection of critical states of the battery cells of the battery units 14, the detection device 34 can be arranged in the battery or in the individual compartments 24 with sensors 34a (cf. 3 ), e.g. temperature sensors. If the temperature in such a compartment 24 exceeds a predefinable threshold value, which is preferably between 80° and 100° C., an ejection process for ejecting the affected battery unit 14 can be initiated. If the limit temperature is exceeded, the relevant battery unit 14 can be discarded immediately, or further measures can optionally be initiated first and/or the fulfillment of further discard safety conditions can be checked.

In addition, it is also possible for motor vehicle 10 to have an environment sensor system 35 . Such an environment sensor system can include at least one or more environment sensors, such as cameras, radars, lidars, ultrasonic sensors or the like. During the dropping process, the surroundings sensor system 35 of the motor vehicle 10 could scan the surroundings for endangered persons and/or facilities and/or other vehicles and/or cyclists and so on and accordingly prohibit or temporarily prevent a dropping. The vehicle electronics could use the navigation system to suggest a route that is less frequented, such as a side street or a dirt road, and is therefore better suited for a drop. In addition, the dropping of a battery module 14 could be coupled directly with an emergency call through which the Fire brigade can be alerted. In the future, dumping and extinguishing zones filled with sand could be provided in cities, which could be controlled via navigation. The vehicle could also eject the battery modules 14 in an automated manner, in particular taking into account environmental sensor data, GPS location and so on. The trigger for shedding is, for example, the measured battery temperature. As soon as a battery cell exceeds a critical temperature, thermal propagation or a battery fire in this cell can no longer be stopped. In such an early stage of the fire, there would still be enough time to drive to a safe drop location and to uncouple the battery modules 14 that are affected.

In a particularly preferred embodiment, the sequence would be as follows: The vehicle 10 registers a thermal runaway of a cell module 14. The driver is urged to stop in a safe place. The affected HV cell module 14 is then ejected, as explained in more detail below. Then the driver is asked to remove the vehicle 10 at least 10 m from the dropping point. This can also be done semi-autonomously with the help of the surroundings sensor system 35 . The great advantage is that if only one cell module 14 or at least not all cell modules 14 are ejected, the vehicle 10 is still drivable. An additional advantage is that maintenance or replacement of defective cell modules can be carried out much more easily and cost-effectively using this type of construction. According to the current state of the art, the entire high-voltage battery must be removed in order to then remove the high-voltage battery cover. This requires the removal of sealing cords and reapplication of a new gasket and battery cover. This leads accordingly to a significantly increased working time.

The ejection mechanism of motor vehicle 10 is designed to be actively controllable, in particular by ejection device control 32. In the event of thermal propagation of a cell or a battery fire in a cell, individual HV cell modules, here individual battery units 14, can be decoupled from vehicle 10. If a critical temperature increase is detected in such an HV (high-voltage) cell module 14, from which point thermal runaway occurs, this affected cell module 14 can be ejected alone. This can be accomplished by the cell module 14 being able to be led out via an openable bottom closure, which is referred to here as the bottom part 28 . This is more detailed again in 2 illustrated.

2 FIG. 12 shows a detailed view of a part 12a of the battery arrangement 12. FIG 1 . In this example, a first battery module 14a is ejected from the associated compartment 24 by opening the associated base part 28a of the housing base 18 . The individual battery units 14, which in the present case are also referred to synonymously as battery modules 14, are therefore held in their associated compartments 25 solely by the base parts 28 associated with them. If the corresponding base parts 28 are opened, the associated battery units 14 fall out of the battery housing 16 and thus also out of the motor vehicle 10 due to the force of gravity. Any electrical connections can be designed in such a way that they are automatically torn off in the process. A respective cell module 14 is therefore located in a separate compartment 24, which, for example, is also located in 3 is illustrated in more detail.

3 14 again shows part of the battery arrangement 12 with a battery module 14 arranged in such a compartment 24 of the battery housing 16. A respective battery module 14 can be connected to the remaining high-voltage architecture, in particular the electrical high-voltage architecture, via a central connection 36. Each cell module 14 also has at least one sensor 34a as part of the detection device 34. This can be designed as a temperature sensor, pressure sensor, gas sensor and/or voltmeter. Several and arbitrary combinations of such sensors are also conceivable. The state of health of the relevant battery cell or battery cells comprised by the battery unit 14 can thus be monitored at any time. Should the sensor 34a detect an impending thermal runaway, ie the cell module 14 can no longer be prevented from bursting into flames in x minutes, the cell module 14 can slide out in a targeted manner via the opening in the compartment floor 28 . The compartment floor 28 or the entire housing floor 18 can be designed from a floor cover 18a and an underride guard 18b or alternatively as a one-piece component 18. As a multi-part design, the compartment floor 28 can also be divided into respective floor parts for the floor cover, i.e. floor cover parts 28a , and subdivide underrun protection parts 28b. In other words, a respective base part 28a in the last-mentioned example also includes a part 28a of the base cover 18a and a part 28b of the underrun protection 18b.

The compartment floor 28 is attached to the rest of the compartment by means of a joining technique, which is referred to below as a fastening device 38 partment or the rest of the battery housing 16 attached, for example by means of screws, bonding, rivets and / or flanging. The joining technique, that is to say the fastening device 38, can be removed, for example by blasting off, screwing on, shearing off, loosening in a form-fitting manner and so on, as will be explained in more detail later.

In addition, various ejection mechanisms can be used to open the relevant compartment floor 28, which are fundamentally 4 and 5 are illustrated in more detail. 4 and 5 show the battery arrangement 12 in each case 3 during the opening of the compartment floor 28 or with the compartment floor 28 open 3 all fastening devices 38, via which compartment floor 28 is fastened to the rest of the housing 16, are thereby released. The compartment floor 28 is thus ejected as a whole, as a result of which the associated battery module 14 also falls out of the housing 16 and thus out of the motor vehicle due to the force of gravity. According to 5 the compartment floor 28 is fastened on one side to the rest of the housing 16 via a hinge 38a. To open the compartment floor 28, all of the fastening elements 38 other than the hinge 38a are released. As a result, the compartment floor 28 folds open like a flap, as a result of which the associated battery module 14 can fall out.

If the motor vehicle 10 has, for example, only a very small ground clearance, the individual cell modules 14 can also be made correspondingly smaller so that they can be ejected without problems even in the case of low, flat-bottomed vehicles. For example, the individual battery units 14 can also be subdivided into subunits 14b, as is shown schematically in 6 is shown. A corresponding number of such subunits can then be accommodated in a common compartment 24 and ejected together if a critical state of a battery cell comprised by these subunits 14b is detected. In the course of such an ejection, the individual subunits 14b can fall out of the opening compartment 25 individually. Due to their reduced height compared to the overall battery unit 14, these can be reliably ejected even if the ground clearance of the motor vehicle 10 is very small. With 36a is in 6 refers to electrical contacting of the individual battery subunits with one another. These individual electrical connections 36a can also be torn off in the course of the drop. In a further embodiment variant, an additional jack, in particular one that extends automatically, can be used for flat-bottomed vehicles, or an air suspension system with the possibility of lifting in the z-direction, in order to facilitate dropping.

Advantageous possible opening mechanisms for opening the compartment floor 28 are described below. For this, the 7 , 8th and 9 one fastening device 38 each, via which the compartment floor 28 is fastened to the rest of the housing 16, and a corresponding fastening release unit 40. In general, a respective compartment floor 28 can also be fastened to the rest of the housing 16 via a plurality of such respective fastening devices 38 and released via a number of corresponding release units 40 become. In addition, 7 until 9 a seal 42 is also shown. When the compartment floor 28 is in the closed state, the seal 42 seals the compartment floor 28 in question from the housing parts of the associated compartment. It can thus be ensured during normal operation that no liquid, dust or other contaminants can penetrate into compartment 24 . This seal 42 is designed to be circumferential and closed.

Thus, in all of these examples, a fastener release unit, referred to herein as fastener release unit 40, exists. In an emergency, this is designed to release all fastening devices 38 to be released from the relevant compartment 24 as quickly and simultaneously as possible, so that the cell module 14 falls out of the compartment 24 by gravity. In addition, the electrical connection 36 can be so severe that it fails under a certain tensile force (gravity).

According to a first variant embodiment presented in 7 shown, the fastening release unit 40 is designed as a blasting unit 40a. This enables the compartment floor 28 to be separated quickly from the rest of the housing 16 or the relevant fastening devices 38 designed as screw connections 38b. Such explosive units are generally already known from the prior art and are therefore not explained in more detail here. The screws 38b can be burst open in such a way that this happens simultaneously for all screws 38b of the compartment 24 to be opened, so that the battery module 14 in question can slide out as uniformly as possible.

In a further embodiment, which is 8th is shown, the fastening device 38, which is also designed as screws 38b, can be severed by means of a shearing mechanism 40b, so that the compartment floor 28 can be detached. The shearing mechanism 40b can have electric motors and/or prestressed Springs, for example gas springs, are operated.

Another embodiment is in 9 illustrated, according to which the fastening device 38 is designed as a screw and/or as a pin 38c with a through hole, not shown in detail here, which can be fixed by a locking unit 40c, for example a locking pin 40c. Thus, in an emergency, the detent pin 40c could be released by the release unit 40 by pulling it out from the through hole. As a result, the retaining pins 38c will lose the form fit with the body or the rest of the battery housing 16. Compartment 24 consequently opens.

Other embodiments are also conceivable, which are not explicitly shown here. For example, in a further embodiment, a screwdriver unit can also be provided as a fastening release unit 40, which is electrically operated and which can be arranged above a thread or above the screw 38b, which can actively loosen the screw 38b via a mechanical connection, for example a slotted screwdriver . The screws 38b can thus be unscrewed from the thread starting from the tip of the screw. The power can be transmitted by means of the usual geometries, for example cross, slotted, Allen, hexagonal, torx geometries and so on. A screw 38b is preferably unscrewed upwards from the compartment floor 28, which makes it easier for the compartment floor 28 to fall off or open downwards. Such a screw 38b can, for example, be screwed through the compartment floor 28 from above and fastened on the underside by means of a counterpart, for example a nut, which in turn is connected to the compartment floor 28 firmly, in particular also in a torque-proof manner. Alternatively, the screw could also only be screwed into a corresponding counter-threaded part with an internal thread that is firmly connected to the compartment floor 28 .

Overall, the examples show how the invention can be used to provide battery module shedding in the event of an upcoming battery fire or thermal propagation, as well as an optimized cell module change.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 202017001021 U1 [0002]
• CN 109895720A [0003]
• CN 111703305A [0004]
• WO 2020247704 A1 [0005]

Claims (10)

Motor vehicle (10) with a battery arrangement (12), which has: - at least one first battery unit (14, 14a) with at least one first battery cell; - A detection device (34, 34a), which is designed to detect a specific critical state of at least the at least one first battery cell; - an ejection device (32, 40, 40a, 40b, 40c), which is designed to point the first battery unit (14, 14a) at least partially downwards with respect to a vertical axis of the vehicle in the event that the specific critical state of at least the first battery cell is detected jettison motor vehicle (10); characterized in that - the battery arrangement (12) has at least one second battery unit (14) with at least one second battery cell; - wherein the ejection device (32, 40, 40a, 40b, 40c) is designed to, at least in the event that the specific critical state of the at least one first battery cell and not for the at least one second battery cell is detected, the first battery unit (14, 14a) to drop independently of the second battery unit (14). Motor vehicle (10) after claim 1 , characterized in that the battery arrangement (12) comprises a battery housing (16), wherein at least the first battery unit (14, 14a) is arranged in the battery housing (16) which comprises a housing base (18) which at least the first battery unit ( 14, 14a) from the surroundings (20) of the motor vehicle (10) at the bottom, wherein the ejection device (32, 40, 40a, 40b, 40c) for ejecting the first battery unit (14, 14a) is designed to have at least one of the to open the first base part (28) of the housing base (18) assigned to the first battery unit (14, 14a), in particular so that a first housing base opening assigned only to the first battery unit (14, 14a) is provided and the first battery unit (14, 14a) is ejected and the first battery pack (14, 14a) falls through its associated housing base opening, at least in part by gravity. Motor vehicle (10) according to one of the preceding claims, characterized in that the battery arrangement (12) has a plurality of battery units (14, 14a) comprising the at least one first and second battery unit (14, 14a), a respective battery unit (14, 14a) has at least one battery cell, the battery housing (16) having a plurality of receiving areas (24) which are separated from one another in particular by partitions (26) in which the battery units (14, 14a) are arranged, the housing base (18) having a plurality of the respective Battery units (14, 14a) associated base parts (28), wherein the ejection device (32, 40, 40a, 40b, 40c) is designed to open the respective base parts (28) independently of one another. Motor vehicle (10) according to one of the preceding claims, characterized in that at least the first floor part (28) is designed as a flap, the ejection device (32, 40, 40a, 40b, 40c) being designed to eject the first battery unit (14, 14a) to open the flap or wherein at least the first base part (28) can be uncoupled as a whole from the battery housing (16) in order to drop the first battery unit (14, 14a) by means of the dropping device (32, 40, 40a, 40b, 40c). . Motor vehicle (10) according to one of the preceding claims, characterized in that the battery units (14, 14a) are each provided by only the single battery cell they comprise, or a respective battery unit (14, 14a) represents a battery module which comprises a plurality of the at least one Battery cell includes. Motor vehicle (10) according to one of the preceding claims, characterized in that the ejection device (32, 40, 40a, 40b, 40c) is designed, in the event that the specific critical state of the at least one first battery cell is detected, to check whether at least one first release safety condition is met and the at least one first battery unit (14, 14a) is not released until the first release safety condition is met. Motor vehicle (10) according to one of the preceding claims, characterized in that the motor vehicle (10) is designed to actively continue to move even when the first battery unit (14, 14a) has been ejected, with an energy supply for operating the motor vehicle (10) being provided by the at least a second battery unit (14) can be provided. Motor vehicle (10) according to one of the preceding claims, characterized in that the motor vehicle (10) has at least one environment sensor (35) for detecting at least part of an environment (20) of the motor vehicle (10), the motor vehicle (10) being designed for this is to move away automatically from a dropping point at which the first battery unit (14, 14a) was dropped, depending on the at least one part of the environment (20) detected by the at least one surroundings sensor (35). Motor vehicle (10) according to one of the preceding claims, characterized in that at least the first base part (28) is arranged with at least one fastening device (38, 38b, 38c) on the battery housing (16), the ejection device (32, 40, 40a, 40b, 40c) having a fastening release unit (40, 40a, 40b, 40c ) which is designed to release the at least one fastening device (38, 38b, 38c) in order to open at least the first base part (28), in particular wherein - the fastening release unit (40, 40a, 40b, 40c) has a blasting unit (40a) which is designed to explode the at least one fastening device (38, 38b, 38c); and/or - the fastening release unit (40, 40a, 40b, 40c) has a shearing unit (40b) which is designed to cut the at least one fastening device (38, 38b, 38c) designed as a screw (38b) or pin (38c). to sever and/or - the fastening device (38, 38b, 38c) is designed as a bolt (38c) or pin (38c) with a through-opening through which a retaining pin (40c) is guided, the fastening-release unit (40, 40c) adapted to remove the retaining pin (40c) from the through hole; and/or - the fastening device (38, 38b, 38c) is designed as a screw device (38b), the fastening release unit (40, 40a, 40b, 40c) being designed to move the screw device (38b) upwards, at least out of the first floor part (28) to unscrew. Method for dropping a first battery unit (14, 14a) with at least one first battery cell from a motor vehicle (10), wherein the first battery unit (14, 14a) is directed at least partially downwards from the motor vehicle (10) with respect to a vehicle vertical axis, at least in the case of a Detection of a specific critical state of at least the first battery cell is discarded, characterized in that at least in the event that the specific critical state of the at least one first battery cell is detected and not for at least one second battery cell of a second battery unit (14, 14a) of the motor vehicle ( 10) is detected, the first battery unit (14, 14a) is ejected independently of the second battery unit (14, 14a).

Images