CN117525627A

CN117525627A - Protection device for protecting a high-voltage battery of a motor vehicle from liquid penetration and motor vehicle

Info

Publication number: CN117525627A
Application number: CN202310964504.4A
Authority: CN
Inventors: T·恩青格; T·霍夫曼
Original assignee: Audi AG
Current assignee: Audi AG
Priority date: 2022-08-03
Filing date: 2023-08-02
Publication date: 2024-02-06
Also published as: DE102022119476A1

Abstract

The invention relates to a protection device (30) for a motor vehicle (28) for protecting a high-voltage battery (32) of the motor vehicle (28) from penetration by a liquid (44), wherein the protection device (30) has a component (34, 36) which can be connected to the high-voltage battery (32) by means of a cable (38, 72) and has a component housing (34 a) and a discharge device (56) which is connected to the component housing (34 a) and by means of which the liquid (44) can be discharged from the component housing (34 a) into an environment region (60) of the component (34, 36) outside the high-voltage battery (32) when the liquid (44) penetrates into the component housing (34 a).

Description

Protection device for protecting a high-voltage battery of a motor vehicle from liquid penetration and motor vehicle

Technical Field

The invention relates to a protection device for a motor vehicle for protecting a high-voltage battery of the motor vehicle from liquid penetration.

Background

In principle, in order to prevent liquids from penetrating into the battery housing, the battery housing of a high-voltage battery for a motor vehicle is sealed in a fluid-tight manner and in particular with respect to the environment. If the liquid reaches into the battery case, this may cause a short circuit of the battery cells and, in the worst case, ignition of the battery. In principle, the possibility still exists in very rare fault situations that liquid may reach the battery housing, for example in the event of a leakage of the coolant system.

DE 10 2014 114 023 A1 describes a battery system having a housing and a plurality of electrical cells arranged therein, and a cooling element, wherein a fluid coupling and an electrical coupling are arranged in the housing, which electrical coupling is electrically coupled to the electrical cells, wherein the fluid coupling and the electrical coupling are arranged at opposite covers of the housing. By means of the spatial separation, the risk of short-circuiting in the case of leakage can be reduced. The housing may furthermore have a valve with a gas-permeable and liquid-tight membrane, and furthermore an air-drying element which acts within the housing. The valve can also be designed as an overpressure valve.

Nevertheless, it is still desirable to improve the safety in relation to the possible penetration of liquid into the high-voltage battery.

Disclosure of Invention

The object of the present invention is therefore to provide a protection device and a motor vehicle, by means of which the high-voltage battery of the motor vehicle can be protected as well as possible against damage by liquids.

This object is achieved by a protection device and a motor vehicle having the features according to the respective independent claims. Advantageous embodiments of the invention are the subject matter of the dependent claims, the description and the drawing.

The protection device for a motor vehicle according to the invention for protecting a high-voltage battery of a motor vehicle from penetration of a liquid comprises a component which can be connected to the high-voltage battery by means of a cable and has a component housing and a discharge device which is connected to the component housing and by means of which, in the event of penetration of a liquid into the component housing, liquid can be conducted out of the component housing into a component environment region outside the high-voltage battery.

The invention is based on the recognition that liquid can penetrate directly into the high-voltage battery or the battery housing, for example, due to leakage of coolant hoses extending inside the battery, and the like, but in principle there is the possibility that liquid can also reach the high-voltage battery, in particular, through cables connected to the high-voltage battery. Such cables are generally multi-layered and comprise a plurality of cavities, for example between individual conductive strands and/or between individual cable layers, for example shields, insulations, covers, etc. In general, a plurality of high-voltage components within a motor vehicle are coupled or electrically coupled to a high-voltage battery directly or indirectly via such a high-voltage line, which in addition generally has a relatively large cross section. Now, if liquid reaches such a motor vehicle component that differs from the high-voltage battery itself, for example due to leakage of a cooling device coupled to the component, the liquid in the component may not only cause damage to the component itself and may also cause failure of the system, but the liquid may also reach other components through the cable and, in the worst case, even into the high-voltage battery, although the probability of such a worst case is very low due to interlocking of various very rare fault events. The invention now makes use of the recognition that additional protection for the high-voltage battery is provided by just providing the motor vehicle component, which is or can be electrically coupled to the high-voltage battery, with a corresponding protection device, i.e. with a drain device by means of which, in the event of liquid penetrating into the component housing of the component, liquid can be drained, in particular so that the liquid cannot reach the cable, which leads directly or indirectly to the high-voltage battery. By means of the drainage device, it is thus advantageously achieved that the low risk that the always present liquid can reach the high-voltage battery is further significantly reduced, and thus further contributes to an improved stability. Furthermore, the provision of such a discharge device has the further advantage that: by the fact that the liquid can be discharged purposefully via the discharge device, leakage of the liquid into the environment can be detected significantly more easily. That is, the liquid does not collect in an undetectable manner in the high-voltage battery or other high-voltage component, but leaves from the component and can therefore be detected significantly more simply. In this way, it is advantageously achieved that, without liquid sensors or the like, which have not been installed in high-voltage components or high-voltage batteries in general, a fault situation can be detected, from which liquid penetrates into certain components of the motor vehicle, in particular high-voltage components, in an undesirable manner. Furthermore, by providing the discharge device, an overpressure in the relevant component, which is caused by the liquid penetrating in the event of a fault, can also be limited, so that discharge sparks acting on other components can be eliminated or at least significantly reduced. In other words, the discharge of the liquid causes a pressure decrease, whereby it can be prevented that the liquid is pumped into the high-voltage battery through the cable by the pressure.

A component which can be connected to the high-voltage battery by means of a cable, in particular an electrically connectable component, is understood to be a component which, in a defined arrangement in its motor vehicle and when coupled in a defined manner by means of at least one cable, is electrically connected to the high-voltage battery indirectly or directly. Preferably, the component may be a component that is part of a high voltage on-board power supply of a motor vehicle. In particular, the component may be a high voltage component, in particular an electrical high voltage component. The coupling for the charging cable in the charging socket of the motor vehicle is also understood to be a high-voltage component of this type. Just the high voltage components are coupled to each other or directly or indirectly to the high voltage battery, for example by a junction box, a so-called battery junction box (Battery Junction Box), by a relatively thick high voltage cable. Thus, the high voltage cable generally has a relatively large cable cross section, in particular in the range of a few square millimeters, for example a cross section of at least 4 square millimeters, in particular at least 5 square millimeters or at least 6 square millimeters, particularly preferably at least 7 square millimeters or at least 8 square millimeters, etc. Just as a result of the cable with such a large wire cross section, the risk of undesired continued guiding of the liquid in case of accumulation of liquid in the relevant components is notable. It is therefore very advantageous to provide the discharge means just in such a component. In particular, the various components of the high-voltage vehicle power supply with such a discharge device can be designed as part of the protection device. Thereby the safety can be further improved.

The environmental area of the component is understood to mean the environmental area of the motor vehicle in which the protection device is applied, that is to say the area outside the motor vehicle or the area outside the component but also inside the motor vehicle. The protection device may also have a collection container into which the liquid can be led out. In this case, it is likewise possible to draw the liquid out into the environment, since such a discharge is only considered in very rare cases in order to prevent more serious reactions in the high-voltage battery.

Next, the protection device is described with reference to only one component and its discharging device. However, these embodiments can also be implemented in a similar manner for any other component, in particular for a plurality of components at the same time.

For example, one of the components of this type that is most susceptible due to the power density is a pulse converter for a drive of a motor vehicle, i.e. which regulates the dc voltage supplied by a high-voltage battery into a three-phase alternating current for operating the drive motor. The reason is that the pulse transformer has internal cooling channels, which in extreme cases may be damaged by short circuits in the component, that is to say in the pulse transformer. In this case, the motor vehicle may also comprise a plurality of pulse converters, for example for a front axle drive and for a rear axle drive. Other critical components that may represent the component are, for example, a DC/DC converter, a charging device, a charging socket in which the connection for coupling to an external charging cable is located, or in principle all components that have an internal cooling device or an interface to the environment of the motor vehicle, for example a charging socket, and are connected in operation to a high-voltage battery, in particular by a cable.

According to a further advantageous embodiment of the invention, it is therefore provided that the component is a pulse transformer. For the reasons mentioned above, pulse converters are particularly critical components in connection with possible liquid penetration. In general, pulse converters comprise power electronics, for example in the form of MOSFETs (metal oxide semiconductor field effect transistors) or IGBTs (insulated gate field effect transistors), which supply extremely high currents for driving motors, which can for example operate with powers in the range of 200 kw. Accordingly, such power semiconductors must be strongly cooled. Nevertheless, if for some reason this is overheated, the power semiconductor may burn out, which may break the tightness of the internal cooling channel due to the high current, so that the cooling water may directly reach the pulse transformer. Without any countermeasures, such a pulse transformer can be flowed over very quickly, since the pulse transformer generally has only a small cavity volume, and accordingly also a cable connection to the high-voltage battery is reached quickly, through which water can then reach the high-voltage battery. For this purpose, even no drop from the pulse transformer to the high-voltage battery is required, since water can be pumped into the battery without countermeasures due to the water pressure caused by the pressure in the cooling cycle where the cooling device of the pulse transformer is coupled to the cooling cycle. By providing the drainage device in or at the component pulse transformer, i.e. the drainage device described, it is thereby possible to provide for the cooling water which enters the pulse transformer in an undesirable manner to be led out in advance, so that, on the one hand, access to the cable connections of the cables leading to the high-voltage battery can be prevented and, furthermore, the coolant pressure in the pulse transformer can also be limited, since a high fluid pressure cannot be built up within the pulse transformer by the drained liquid. As already described above, however, the respective other components are also suitable for the provision of the respective discharge device here to protect the high-voltage battery.

In a further advantageous embodiment of the invention, the discharge device is designed with a protection mechanism in order to prevent liquids and/or waste from penetrating into the component housing via the discharge device. This is very advantageous, since it is thereby prevented that the discharge device itself may become a risk source in connection with the penetration of liquid. At this point, there are various solutions in which the draining means are designed to prevent the penetration of liquids and/or refuse in a reliable manner.

In particular, the discharge device is preferably designed with at least one of the following protection mechanisms: for example, the drain may be designed with a liquid outlet line coupled to the component housing. Such a liquid outlet line provides a significantly higher flexibility in terms of the discharge of liquid and furthermore prevents liquid from penetrating into such a line from the outside and possibly reaching the components. Furthermore, it can be provided that the liquid outlet line can be of, for example, a multiple-coiled design, in particular of a siphon-type and/or labyrinth-type design. This prevents in particular dust and dirt from reaching the component housing, since such particles are deposited at the labyrinth coils. Therefore, smaller droplets or splashed rainwater or the like are also unlikely to reach into the component housing. According to a further measure of protection, it can be provided that the liquid outlet line opens into a predetermined, protected environment region of the motor vehicle. That is, in this case, the liquid that collects in the component is led out into the environment of the motor vehicle. In this case, it is advantageous if the opening of the line is guided to a motor vehicle location as an interface with the environment, which opening is not particularly exposed to environmental influences, for example in the region of the cover, at the tail, etc. It is also conceivable for the liquid outlet line to open into the interior region of the motor vehicle, in particular into the region of the luggage compartment of the motor vehicle. The access area is particularly well protected and is not exposed to environmental influences, in particular to moisture. For example, in a luggage compartment, a collection tank or the like may be provided for collecting liquid there. For example, a service technician of a motor vehicle may also periodically check here to determine if there may be a coolant leak or other fault condition that causes undesirable coolant accumulation in components of the motor vehicle. The outlet line can thus advantageously be arranged such that it opens into a space that is protected from dirt and external water. Furthermore, the body component of the motor vehicle, which is at least partially designed with a cavity, and/or the chassis bracket and/or the trim part, which is designed with such a cavity, can also be part of the protection mechanism, the part housing being coupled indirectly to the body component and/or the chassis bracket and/or the trim part or directly to the body component and/or the chassis bracket and/or the trim part via a liquid line which is coupled into the part housing. In other words, liquid can also be introduced from the component housing into the cavity of such a component. Such components with cavities are, for example, assemblies, axle brackets, beams, such as a-pillars, B-pillars, C-pillars or D-pillars, side sills, rear axle brackets, auxiliary frames, etc. This is also a particularly protected area where water, dust or dirt cannot easily reach from the environment. In general, most of these components are always provided with small holes or the like, which also enable the introduced water or the introduced liquid to flow out into the environment of the motor vehicle. If necessary, such a component can also be provided with a drain plug. Only when the drain plug is opened, for example manually, the water or liquid that is guided into the cavity is discharged and as soon as the drain plug is closed, the liquid collects in the cavity. This can be used for monitoring or diagnosis in a repair shop.

According to a further advantageous embodiment, the discharge device can also have a filter as a protection. The filter can be designed, for example, as a dust filter or the like. Thus, infiltration of contaminants into the component housing can be effectively prevented. It is also possible for the discharge device to have a closing device. Such a closure device can also take on various forms, for example in the form of a valve, for example an overpressure valve, a sluice, in particular a pretensioned sluice, a membrane similar to a tomato sauce bottle, a bursting membrane which ruptures on overpressure, etc. In this case, it is particularly advantageous if the closing means has a single-sided opening direction. In other words, the closure device can only be opened if a defined minimum pressure or a defined minimum force or a defined overpressure acts on the closure device from a defined first direction, but not if the action is performed from a second, for example opposite direction. This can be achieved, for example, by an overpressure valve which can be opened only in one direction, that is to say only when a defined overpressure is present within the component housing, or by the preloaded flap. In the simplest case, the gate may be provided with a tensioned spring which presses the gate against the support. The same directional force as the tensioning force cannot open the gate. The oppositely acting forces, which are greater than the spring force, open the gate. For example, the overpressure valve can be designed as spring-loaded and as a ball or cone, for example made of plastic or metal. The ball or cone is correspondingly spring-pressed against the abutment. The sphere or cone thereby closes the opening in the component housing. The closure can also be designed as a membrane with already existing small openings, similar to a slit, but such a membrane breaks only under a corresponding pressure in one direction, but does not allow dust or liquid to pass under pressure in the opposite direction.

The design of the discharge device with a valve, in particular as a protective mechanism, is very advantageous, so that this is also a preferred embodiment of the invention. The valve is designed to open automatically from a predetermined overpressure relative to the ambient pressure in the environment. Thus, no manipulation is required to open the opening of the discharge device. At the same time, a particularly effective protection mechanism can thereby be provided. Furthermore, the protection mechanisms can also be combined with each other in any way. In other words, in particular such a valve can be combined with any other of the above-mentioned protection mechanisms, for example with a safe discharge position of the liquid outlet line, to which the valve can be coupled.

It is furthermore advantageous if the overpressure from the opening of the valve is selected as small as possible and in particular smaller than the pressure required for overcoming the high-voltage cable and the resistance of the high-voltage cable at the connection point of the high-voltage battery. For example, the opening pressure or overpressure may be less than 0.5Bar or 0.4Bar or 0.3Bar or 0.2Bar, in particular less than 0.1Bar, for example also less than 0.05Bar.

In a particularly advantageous embodiment of the invention, it is provided that the high-voltage battery is designed with a base tightness at the connection point of the cable according to a defined overpressure value, for example about 0.5Bar, and that the overpressure from the opening of the valve is smaller than the defined overpressure value, for example 0.3Bar. If the high-voltage battery obtains a basic tightness of approximately 0.5Bar at its connection point, that is to say if the high-voltage battery is designed to be sealed up to an overpressure including 0.5Bar, and the outlet opens from an overpressure of 0.3Bar, it is ensured that water cannot penetrate into the high-voltage battery, in particular without having to face the problem of a technically challenging or difficult sealing against high voltages in the region of the connection point.

In a further advantageous embodiment of the invention, the outlet device has a permanent opening in the component housing, from which opening the liquid can be led out directly from the component housing after reaching the opening, in particular independently of the pressure of the liquid. Although the opening offers less protection than the above-described valve, in particular an overpressure valve, it is thus already possible to draw a minimum amount of liquid directly out of the component housing, instead of having to draw it out when a defined overpressure is established in the component housing. Thus, by just the other protection mechanisms described above, a reliable and safe liquid extraction can still be provided, and at the same time refuse, dust or external liquid penetration is prevented.

In a further advantageous embodiment of the invention, the component housing has a coupling for the connection of the cable to the high-voltage battery, which coupling is arranged above a first outflow opening provided by the outlet device directly adjacent to the component housing or arranged on the component housing side and/or above a second outflow opening adjacent to an environment region into which liquid can be conducted, in relation to a defined installation position of the component in the vehicle. It is therefore advantageous if the cable connection for the cable to be connected to the high-voltage battery is higher than the first outflow opening, to which liquid which has penetrated into the component housing in an undesired manner first reaches and can thus be led out before the liquid reaches the high-voltage battery via the cable. It is furthermore advantageous if the second outflow opening differs from the first outflow opening and the liquid finally passes through the second outflow opening into the environment region, the second outflow opening being lower than the cable connection to the high-voltage battery, since the liquid can thus flow out of the outflow opening before the liquid level in the component housing reaches the high-voltage battery via the cable.

In principle, it is advantageous to keep the discharge device as low as possible, but also the entire component as low as possible with respect to the high-voltage battery. Since the penetration of liquid into the high-voltage battery through the cable is thereby also hindered by gravity, even if the liquid reaches the cable coupling.

In a further advantageous embodiment of the invention, the protection device has a cooling device for cooling the component, wherein the cooling device is arranged at least partially inside the component housing or outside the component housing on the component housing. In other words, the described protection measures are particularly advantageous when the protection device is used in components that can be actively cooled by means of a cooling device or actively cooled in operation. Because just for such a component there is an increased likelihood of liquid penetrating into the component housing.

In addition, in this case, other countermeasures are also possible. For example, a further very advantageous embodiment of the invention provides that the protection device has a detection device for detecting a predetermined fault situation and a control device, which is designed to shut off at least a first cooling circuit section comprising the cooling device, in particular directly or stepwise or with a delay of a predefinable time, when such a predetermined fault situation is detected. As a result, it is thereby prevented that the coolant is continually actively pumped into the damaged component or its component housing via the first cooling circuit part. Thereby, the fluid pressure within the component may be at least slightly reduced. In the event of a fault, in the event of a leakage of the cooling device, the coolant is pressed under pressure into the component without cutting off the cooling circuit. In particular when the component is not provided with a drain, this pressure is sufficient for guiding the coolant also into other high-voltage components through the high-voltage line up to the high-voltage battery. But without the evacuation device or other means, the individual deactivation of the circulation portion is rarely utilized. The reason for this is that, since the cooling system is usually closed, the coolant in the cooling system is also under pressure due to temperature, and this is not the only reason, and also because the coolant is pumped in a circulating manner under pressure with a certain volume flow by means of a coolant pump. It is therefore generally not possible to actively reduce the system pressure in the cooling system due to the system temperature, since it is only possible to reduce the system pressure when the temperature drops to ambient temperature, or the system is opened, as is now specified in the scope of the invention, which can be achieved by the evacuation device. I.e. thereby, the coolant pressure is additionally also reduced to the outside. Thus, in combination with the deactivation of the first coolant circulation portion, the penetration of the liquid into the high-voltage battery can be prevented particularly effectively. Furthermore, 50 ml, 100 ml, 1000 ml or even 2000 ml of water may leak out, and more water may leak out due to the installation position of the relevant components.

The detection device may be designed such that it is not necessary to detect an undesired penetration of liquid into the relevant component, but such a fault situation may also be detected indirectly. For example, the detection means may detect a corresponding failure of the relevant component itself, such as a functional failure or a communication failure with the component. All of these may be defined as predetermined fault conditions and accordingly there is no need to provide a liquid sensor within such a component. Thus, if such a fault condition is detected, the control means may trigger the shut-off of the cooling cycle portion. Depending on the component concerned, it may be advantageous here not to deactivate the cooling immediately by deactivating the respective cooling circuit part, that is to say to deactivate the pump which pumps the coolant through the first cooling circuit part. It is advantageous if the cooling of the pulse transformer is deactivated only when the pulse transformer is set in operation or at least when the pulse transformer is operated in a severely reduced power mode, in order to prevent burnout of the power electronics described above, if the component is the pulse transformer or if such a pulse transformer is thermally coupled for cooling at the same cooling circuit part, i.e. the first cooling circuit part. Thus, before the partial or complete deactivation of the first cooling cycle is deactivated, it is possible, for example, to wait for a predefinable time, for example in the range of seconds or minutes, for example five minutes, or also until the motor vehicle has stopped, for example after an immediate stop request has been made to the driver. It is also conceivable to stepwise decrease the pump power of the first cooling circuit part.

In a further advantageous embodiment of the invention, the control device is designed to switch on or continue to operate, in particular with increased or maximum cooling power, a second cooling circuit part associated with the high-voltage battery, which can be controlled independently of the first cooling circuit part. In principle, it is highly advantageous in this case to increase the cooling power for the high-voltage battery. If the high-voltage battery is not currently cooled, cooling may be activated accordingly upon detection of a fault condition. If the high-voltage battery has been cooled, the cooling power is increased, if applicable, or the maximum cooling power is adjusted, if the maximum cooling power has not been adjusted. For example, the pump associated with the second cooling circuit part, i.e. the pump in the high-voltage battery cooling circuit, can be completely controlled in order to protect the high-voltage battery from thermal reactions, optionally involving active battery cooling.

For example, if the relevant component is located in the same cooling cycle portion as the high voltage battery, it is preferable that the coolant pressure in the relevant cycle portion is still reduced to a minimum and in particular the cooling cycle portion is deactivated, since coolant that is typically pressed into the high voltage battery under pressure may cause greater damage than temporarily interrupting battery cooling.

The first and second cooling circuit sections may be designed such that they can be coupled to one another under certain conditions and can be operated as a common cooling circuit or can be operated separately from one another, so that, for example, the cooling temperature can be set independently for each circuit section. If the two cooling circuit sections are in the connected state at the time of the detection of the fault situation, the control device can also be designed to separate the two cooling circuit sections beforehand by actuating at least one valve or a plurality of valves. Thus, for example, the high-voltage battery and its cooling can be operated in an island cycle, and the cooling or cooling cycle part of the powertrain likewise operates in the island cycle. This advantageously achieves a further cooling of the high-voltage battery, while at the same time the coolant pressure in the damaged component can be reduced as rapidly as possible.

Furthermore, the protection device may also comprise a high voltage battery. The high-voltage battery may have a plurality of electrical cells, alternatively the electrical cells may be combined into a battery module and furthermore arranged in a common battery housing. For example, the battery cell may be designed as a lithium ion battery cell.

The invention also relates to a motor vehicle having a protection device according to the invention or one of its embodiments and in particular having a high-voltage battery.

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

The invention also includes combinations of features of the described embodiments. Thus, the invention also includes implementations having a combination of features of a plurality of the described embodiments, respectively, as long as the embodiments are not described as mutually exclusive.

Drawings

Embodiments of the present invention are described next. Wherein:

fig. 1 shows a schematic diagram of a pulse transformer and a high voltage battery in case of coolant leakage according to an example not belonging to the invention;

fig. 2 shows a schematic view of a motor vehicle with a protection device according to an embodiment of the invention;

fig. 3 shows a schematic view of a protective device for a motor vehicle according to another embodiment of the invention.

Detailed Description

The examples described below are preferred embodiments of the present invention. In the examples, the described components of the embodiments are each individual features of the invention which can be regarded as independent of one another and which also improve the invention independently of one another. Thus, the present disclosure should also include different combinations of features than those of the illustrated embodiments. Furthermore, the described embodiments may be supplemented by other of the already described features of the invention.

In the drawings, like reference numerals designate functionally identical elements, respectively.

Fig. 1 shows a schematic illustration of a pulse transformer 10 and a high-voltage battery 12 according to an example which does not belong to the invention, in the case of a leakage 14 through a coolant line of the pulse transformer 10 in the form of a cooling channel 16. The pulse transformer 10 is coupled to the high voltage battery 12 by a cable 18. If a leak occurs in the cooling channel 16 through the pulse transformer 10, the cooling liquid 20 reaches into the housing 22 of the pulse transformer 10, thus rapidly filling the pulse transformer. The liquid level may also reach the connection area 24 of the cable 18 to the high-voltage battery 12, so that now also the cooling liquid may reach the interior 26 of the high-voltage battery 12. Even if, as shown here, the cable guide 18 has no drop, it is in principle also possible, due to the coolant pressure in the cooling circuit, to pump the coolant 20 collected in the pulse transformer 10 into the battery 12 with pressure. In other words, in the event of a fault, the coolant 20 is pressed into the pulse transformer 10 due to the pump pressure of the cooling circuit and, in addition, by the pressure generated by the temperature in the cooling system. Such pressure may be sufficient for guiding the coolant 20 through the high-voltage line 18, and possibly also through other high-voltage components, all the way into the high-voltage battery 12.

Furthermore, the system pressure in the cooling system, which is generated by the system temperature, cannot be reduced, at least not actively, because it is only possible to reduce the system pressure when the temperature drops to ambient temperature.

Fig. 2 shows a schematic view of a motor vehicle 28 with a protection device 30 according to an embodiment of the invention. The components of the motor vehicle 28 described below can also be considered here as part of the protection device 30 or as belonging to the protection device 30. In this case, the motor vehicle 28 has a high-voltage battery 32. Furthermore, motor vehicle 28 has a component 34, which in this example is designed as a pulse transformer 36. In general, however, the component 34 may be any, particularly high voltage, component that is electrically connected to the battery 32 via a cable 38, particularly a high voltage cable. In this example, the pulse transformer 36 may in turn be cooled by means of a cooling device 40 which is part of a first cooling cycle portion 42. Here, the coolant 44 is pumped through the first cooling circuit part 42 by means of a pump 46 assigned to the first cooling circuit part 42, and thus cools the pulse transformer 36 in normal operation. The cooling device 40 can be integrated into the pulse transformer 36 or at least be located on or arranged at the housing 34a of the pulse transformer. In this case, the cooling device 40 may comprise one or more cooling channels for guiding the coolant 44, which cooling channels may also be integrated into the pulse transformer 36.

A second cooling device 48 may also be provided for the high-voltage battery 32, which may cool the high-voltage battery 32 as desired. Here, the cooling device 48 is part of a second cooling circulation portion 50, which is assigned a second coolant pump 52 for pumping the coolant 44 through the second cooling circulation portion 50. The two cooling circuit sections 42, 50 can also be operated in this case coupled to one another or separately from one another.

For this purpose, corresponding valve means can be provided. The valve device can be configured to be actuated by means of a control device 54, for example.

Advantageously now, the component 34, in the present example the pulse transformer 36, is designed with a discharge device 56, which is connected or coupled to the housing 34a, so that a flow connection exists or can be established between the interior of the housing 34a and the discharge device 56. If a leakage 58 of the cooling device 40 of the pulse transformer 36 occurs, water or, in general, the cooling fluid 44 that collects in the housing 34a can be conducted out of the component housing 34a via the outlet device 56 into a different environment than the high-voltage battery 32, which in this example corresponds to the environment 60 of the motor vehicle 28. In this example, the component housing 34a has a first outflow opening 62 through which the liquid 44 can be introduced into a liquid outlet line 64 and into the environment 60 through the liquid outlet line and through a second outflow opening 66. In general, the discharge device 56 may have different manifestations to be described later in detail.

The provision of such a drain 56 advantageously prevents the liquid 44 that collects in the housing 34a from being able to reach the high-voltage battery 32. The pressure generated by the liquid 44 accumulated in the housing 34a is particularly limited. In particular, it is thereby even completely impossible to build up the system pressure prevailing in the first cooling circuit part 42, since this system pressure is immediately reduced again by the discharge device 56 and the water flowing out. Accordingly, it is not possible for the liquid level to rise to such an extent that it is possible to reach the coupling 68 of the cable 38 with the high-voltage battery 32. It is correspondingly advantageous, in particular with respect to this coupling portion 68, for the positioning of the first discharge opening 62 of the discharge device 56 to be as low as possible. It is also advantageous if the positioning of the component 34 within the motor vehicle 28 as a whole is as low as possible with respect to the motor vehicle vertical axis of the motor vehicle 28, in particular with respect to the high-voltage battery 32. It is also advantageous if the second outflow opening 66 is arranged below the battery-side coupling 70 of the cable 38, for example, in particular also with respect to the vertical axis of the motor vehicle.

As a further countermeasure, it can now be provided that the control device 54 is decoupled by actuating the respective valves of the cooling circuits 42, 50, which should be in the coupled state, by the correct valve positions of these valves. Thereby cooling the high voltage battery 32 in the island cycle and correspondingly also the powertrain and the pulse inverter 36 in the island cycle. Thus, by actuating the control device 54, the coolant pump 46 in the drive cooling circuit 42 can be stopped, so that the pressure increase in the first cooling circuit part 42 by the water pump 46 is stopped. The pressure of the pump 46 may be in the range of 0.1Bar across 1.0Bar up to 2 Bar. Alternatively, in order to reduce the pressure in the cooling system, that is to say in the first cooling circuit part 42, as much as possible, the volume flow in the drive cooling circuit 42 can also be minimized, but not completely deactivated. It is furthermore preferred that the control device 54 is used to completely activate the pump 52, i.e. to completely activate the second pump 52 in the high-voltage battery circuit 50, in order to protect the high-voltage battery 32 from thermal reactions.

The system pressure in the cooling system, that is to say in the first cooling circuit part 42, which is generated by the system temperature and cannot be influenced or reduced in practice, can now be actively reduced by the outlet device 56, that is to say externally, that is to say into the environment 60. At this time, 50 ml of water, 100 ml of water, 1000 ml of water, or 2000 ml of water may be leaked, and more water may also be leaked through a low installation position of the component 34 as necessary.

Fig. 3 shows a schematic view of a protection device 30 according to an embodiment of the invention. In particular, the protection device 30 may be configured as described above. Fig. 3 can be understood as a detailed view of the protective device 30 with the component 34 in fig. 2. As cables 38 for coupling the component 34 to the high-voltage battery 32, two high-voltage cables 38 are shown here. Furthermore, the component 34 can also be coupled to other components not shown here, in particular high-voltage components, likewise via further cables, in particular the high-voltage cable 72. The component 34 in turn has a cooling device 40 as part of a first cooling circuit portion 42. In addition, the component 34 may be a pulse transformer 36. Now, there are two possibilities here how the liquid 44 may reach into the interior of the component housing 34 a. On the one hand, due to leakage of the cooling device 40, on the other hand, the liquid 44 can also come from other high-pressure components via the high-pressure cable 72.

The protection device 30 now has a discharge device 56. The discharge device can likewise be designed as described above. In this example, the outlet device is arranged at the lowest possible point of the component 34 with respect to the prescribed installation position of the component in the motor vehicle 28. As a result, the liquid 44 that has permeated into the component housing 34a reaches the drain 56 very early. It is now particularly advantageous to additionally protect the discharge device 56 from infiltration of refuse, dirt or other liquids from the environment 60 by means of a protection device 76. The protection device 76 is designed here in the form of a spring-loaded valve 74. Accordingly, under normal conditions, the first outflow opening 62 is closed by a closure 78 as part of the valve 74, which is pressed against the opening 62 by a spring 80. From a certain overpressure deltap within the housing 34a, the valve 74 opens and thereby opens a path for the liquid 44 outwards through the second outflow opening 66 into the environment 60. Thus, for example, if in normal operation liquid or waste passes through the second outflow opening 66 into the interior of the valve 74, however, it cannot pass through the closed first outflow opening 62 into the interior of the component housing 34 a. The overpressure valve 74 is preferably arranged at a geometrically sound location, for example at the lowest point of the component 34. It is furthermore preferred that the valve 74 is arranged such that it does not open due to external conditions, such as suction caused by the oncoming wind at the ground level, etc.

In addition, other alternative or additional protection schemes exist for realizing that everything, such as dust, water, etc., cannot penetrate from the outside. These other different protection schemes are denoted here as 76a, 76b, 76c, 76d, 76e and 76 f. For example, the geometry of the outlet conduit 64 may be similar to the labyrinth 76a, such that neither dust, sludge nor splash water reaches into the interior of the component 34, particularly even the first outflow opening 62, due to the long and serpentine guide path. Furthermore, the geometry of the outlet hose 64 can also be specially shaped, for example, in order to have an outlet 64a, which can also be, for example, simultaneously a second outlet opening 66, which simultaneously serves as a dust filter. The hose 64 thus has a thin gap at the end 64a through which the liquid 44 can be simply guided out into the environment 60, but dirt and the like cannot penetrate into the hose 64. The geometric filter 76c is also suitable as a protective measure, which is likewise denoted by 76d, for guiding the hose 64 or the line 64 into the interior 82 of the motor vehicle 28, for example, a luggage compartment. As a further protective measure 76e, it can be provided that the liquid 44 is guided via the line 64 to a defined safety point. This may be a well protected area of the vehicle 28 with respect to splash water and the like. It is particularly advantageous to introduce, as a protective measure 76f, for example, the liquid 44 into the hollow body 84 of the vehicle 28, for example into an axle bracket or beam or other body component or the like. The hollow body can also serve, for example, as the outlet line 64 at the same time, or the outlet line 64 can be coupled to the hollow body 84.

As a closure, for example, a gate can also be provided, which is, for example, preloaded. The gate may also be made of plastic or metal. In the worst case, structures which irreversibly break upon overload, such as bursting elements, can also be provided. Typically, the protection device 76 acts as a waste gate for the water intake and is ideally designed to be reversible. In other words, the protective device 76 and, in general, the evacuation device 56 may be reusable and need not be replaced.

Thus, in general, the maximum overpressure in the high-pressure component 34 due to the water 44 entering in the event of a fault can advantageously be limited, so that discharge sparks acting on other components can be eliminated or significantly reduced. By purposefully directing the water 44 at a determined location, a fault condition may also be found to exist for a repair shop.

Generally, examples show how a water-proof valve for high-pressure components can be provided by the present invention. The high-voltage battery can thereby be additionally protected from penetrating water, so that thermal reactions due to water ingress, which may be caused by external influences or damage at the cooling system, for example by violent effects such as accidents, malfunctions in the components, etc., are excluded here. If a high-pressure component, for example a component pulse transformer, is flooded with pressurized coolant in the event of a very rare fault, a sensitive overpressure valve in this component is preferably opened, so that it is not possible to damage other components, for example by conveying water in the longitudinal direction via the high-pressure line. The outlet line of the overpressure valve is arranged such that it opens into a space protected from dirt and external water, for example the interior of the vehicle or into a hollow component, for example an assembly, an axle carrier, a beam or the like. If necessary, these components can be provided with drain plugs for monitoring or diagnosis in repair shops. The geometry of the line can also be designed such that water or dirt cannot penetrate through the line, if necessary the line contains a filter.

Claims

1. A protection device (30) for a motor vehicle (28) for protecting a high-voltage battery (32) of the motor vehicle (28) against penetration of a liquid (44),

it is characterized in that the method comprises the steps of,

the protection device (30) has a component (34, 36) which can be connected to the high-voltage battery (32) by means of a cable (38, 72) and has a component housing (34 a) and a discharge device (56) which is connected to the component housing (34 a) and by means of which, in the event of a penetration of a liquid (44) into the component housing (34 a), the liquid (44) can be guided out of the component housing (34 a) into an environment region (60) of the component (34, 36) outside the high-voltage battery (32).

2. The protection device (30) according to claim 1,

it is characterized in that the method comprises the steps of,

the discharge device (56) is designed with protection means (76; 76a, 76b, 76c, 76d, 76e, 76 f) to prevent liquids (44) and/or refuse from penetrating into the component housing (34 a) via the discharge device (56), in particular wherein the discharge device (56) is designed with at least one of the following protection means (76; 76a, 76b, 76c, 76d, 76e, 76 f):

-a liquid extraction line (64) coupled to the component housing (34 a), the liquid extraction line being of multiple coiled construction, in particular of siphon-type and/or labyrinth-type construction (76 a);

-a liquid outlet line (64) coupled to the component housing (34 a), which liquid outlet line opens into a predetermined, protected environment region (60) of the motor vehicle (28) (76 e);

-a liquid outlet line (64) which is connected to the component housing (34 a) and opens into an interior space region (82) of the motor vehicle (28), in particular into a region of a luggage compartment (82) of the motor vehicle (28);

-a body component (84) and/or a chassis bracket (84) and/or a trim (84) of the motor vehicle (28) which are at least partially designed with a cavity, the component housing (34 a) being coupled to the body component and/or the chassis bracket and/or the trim indirectly via a liquid outlet line (64) which is coupled to the component housing (34 a) or directly to the body component and/or the chassis bracket and/or the trim (76 f);

-a filter (76 b, 76 c);

-a closing device (74) having only one opening direction.

3. The protection device (30) according to any one of the preceding claims,

it is characterized in that the method comprises the steps of,

the outlet device (56), in particular as a protection means (76; 76a, 76b, 76c, 76d, 76e, 76 f), has a valve (74) which opens automatically from a predetermined overpressure (Δp) relative to the ambient pressure in the environment (60).

4. The protection device (30) according to any one of the preceding claims,

it is characterized in that the method comprises the steps of,

the outlet device (56) has a permanent opening in the component housing (34 a), from which opening the liquid (44) can be discharged directly from the component housing (34 a), in particular independently of the pressure of the liquid (44).

5. The protection device (30) according to any one of the preceding claims,

it is characterized in that the method comprises the steps of,

the component housing (34 a) has a coupling (68) for connecting the cable (38, 72) to the high-voltage battery (32), which is arranged, with respect to a defined installation position of the component (34, 36) in the motor vehicle (28), above a first outflow opening (62) provided by the outlet device (56) directly adjacent to the component housing (34 a) and/or above a second outflow opening (66) adjacent to an environment region (60) into which the liquid (44) can be conducted.

6. The protection device (30) according to any one of the preceding claims,

it is characterized in that the method comprises the steps of,

the components (34, 36) are pulse converters (36).

7. The protection device (30) according to any one of the preceding claims,

it is characterized in that the method comprises the steps of,

the protection device (30) has a cooling device (40) for cooling the components (34, 36), wherein the cooling device (40) is arranged at least partially within the component housing (34 a) or outside the component housing (34 a) on the component housing (34 a).

8. The protection device (30) according to any one of the preceding claims,

it is characterized in that the method comprises the steps of,

the protection device (30) has a detection device for detecting a predetermined fault situation and a control device (54) which is designed to shut off at least a first cooling circuit section (42) comprising the cooling device (40), in particular stepwise or with a delay of a predefinable time.

9. The protection device (30) according to any one of the preceding claims,

it is characterized in that the method comprises the steps of,

the control device (54) is designed to switch on or continue operating a second cooling circuit part (50) associated with the high-voltage battery (32), in particular with increased or maximum cooling power, which can be controlled independently of the first cooling circuit part (42).

10. A motor vehicle (28) with a protective device (30) according to any of the preceding claims.