Motor Vehicle Having a Pressure Relief Device That Can Be Thermally Activated, and Method for Pressure Relief

Abstract

A motor vehicle has a pressure relief device that can be thermally activated, for the pressure relief of at least one pressure vessel. A body floor element is arranged at least partially between the passenger compartment or the cargo area and the pressure vessel. A pressure relief triggering device is designed to directly or indirectly bring about the pressure relief. The pressure relief triggering device is designed to absorb thermal energy from the passenger compartment or the cargo area in order to trigger the pressure relief device, without the thermal energy absorbed for the triggering having previously been transmitted to the pressure relief triggering device through the body floor element.

Claims

1.-11. (canceled)

12. A motor vehicle with a pressure relief device which is activatable thermally for pressure relief of at least one pressure vessel, comprising: a vehicle body floor element arranged, at least in regions, between a passenger interior compartment or a trunk and the pressure vessel; a pressure relief trigger configured to bring about the pressure relief directly or indirectly, wherein the pressure relief trigger is configured to absorb thermal energy from the passenger interior compartment or from the trunk in order to trigger the pressure relief device, without the thermal energy which is absorbed for the triggering having previously been transmitted by way of the vehicle body floor element to the pressure relief trigger.

13. The motor vehicle according to claim 12, wherein at least one surface of the pressure relief trigger is arranged at least partially in the passenger interior compartment or in the trunk, or is recessed into the vehicle body floor element.

14. The motor vehicle according to claim 12, wherein the pressure relief device comprises at least one opening element which is activatable thermally, and the pressure relief trigger is configured to activate the opening element thermally.

15. The motor vehicle according to claim 14, wherein the pressure relief trigger is configured to output the absorbed thermal energy at least partially to the opening element.

16. The motor vehicle according to claim 15, wherein a triggering medium is stored in the pressure relief trigger.

17. The motor vehicle according to claim 16, wherein the pressure relief trigger is configured and arranged such that the triggering medium is brought at least partially into contact with the opening element for the thermal activation of the opening element.

18. The motor vehicle according to claim 17, wherein at least one of: the triggering medium has a solid or liquid physical state if the temperature of the triggering medium is lower than a limit temperature, the limit temperature being indicative of a thermal event in the passenger interior compartment or in the trunk; and the triggering medium has a liquid or gaseous physical state if the temperature of the triggering medium reaches or exceeds the limit temperature.

19. The motor vehicle according to claim 18, wherein the pressure relief trigger is arranged and configured such that the triggering medium flows out for the pressure relief solely by the way of gravity and/or by way of a pressure difference between the triggering medium and surroundings.

20. The motor vehicle according to claim 12, wherein the pressure relief trigger has at least one closure, the closure being configured to melt or to burst in case of a triggering temperature being reached or exceeded.

21. The motor vehicle according to claim 12, wherein the pressure relief trigger comprises a triggering line, the triggering line or an element which is operatively connected to the triggering line is guided at least partially through the vehicle body floor element.

22. The motor vehicle according to claim 14, wherein a triggering medium is stored in the pressure relief trigger.

23. The motor vehicle according to claim 16, wherein the triggering medium has a solid or liquid physical state if the temperature of the triggering medium is lower than a limit temperature, the limit temperature being indicative of a thermal event in the passenger interior compartment or in the trunk; and/or the triggering medium has a liquid or gaseous physical state if the temperature of the triggering medium reaches or exceeds the limit temperature.

24. The motor vehicle according to claim 16, wherein the pressure relief trigger is arranged and configured such that the triggering medium flows out for the pressure relief solely by the way of gravity and/or by way of a pressure difference between the triggering medium and surroundings.

25. A method for pressure relief of a motor vehicle, the motor vehicle comprising a pressure relief device for the pressure relief of at least one pressure vessel, the method comprising: absorbing thermal energy of a thermal event at least partially by a triggering medium in a passenger interior compartment or in a trunk of the motor vehicle; transporting the triggering medium, which is heated by way of the absorption, at least partially to an opening element of the pressure relief device, which opening element is activatable thermally, wherein the transported triggering medium outputs the thermal energy at least partially to the opening element, as a result of which the opening element is activated thermally.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIG. 1 shows a diagrammatic cross-sectional view of the technology disclosed herein.

[0043] FIG. 2 shows a diagrammatic cross-sectional view of a further refinement of the technology disclosed herein.

DETAILED DESCRIPTION OF THE DRAWINGS

[0044] FIG. 1 shows a diagrammatic cross-sectional view, in the case of which a pressure vessel 100 has a liner 110 and a fiber reinforced layer 120. The pressure vessel comprises a tank shut-off valve 130 which is inserted at one end of the pressure vessel 100 into a boss of the pressure vessel 100. The pressure vessel 100 and the tank shut-off valve 130 can have any suitable design.

[0045] The pressure vessel 100 is shielded from the passenger interior compartment I or trunk K by way of the vehicle body floor element 300. The vehicle body floor element 300 can be, for example, the central tunnel of a motor vehicle. It is likewise conceivable that the pressure vessel 100 is arranged below the vehicle seats or below the trunk K. Depending on the location of use, the vehicle body floor element 300 can be covered by a carpet material 310. Here, a pressure relief trigger 210 is recessed into the vehicle body floor element 300. Here, an upper surface of the pressure relief trigger 210 protrudes into the passenger interior compartment I or trunk K. The pressure relief trigger 210 which is shown here comprises an internal volume 211, in which the triggering medium is stored. In order to improve the thermal transfer, the pressure relief trigger 210 has a rib structure 212. The pressure relief trigger 210 comprises a closure 216 which is arranged at the lowest point on the underside of the pressure relief trigger 210. In the refinement which is shown here, in its installed position, the pressure relief trigger 210 is arranged directly above the pressure relief unit 200 which can be activated thermally, as viewed in the vehicle vertical axis. A triggering medium channel 214 serves to pour the triggering medium directly onto the opening element of the pressure relief device 200 which can be activated thermally. Any suitable medium can be used as triggering medium.

[0046] The pressure relief device 200 is set up, after being activated thermally, to release a flow path from the interior of the pressure vessel 100 to the surrounding area. Here, the filling and/or removal flow path/paths has/have been omitted for reasons of simplicity. They can be of any desired configuration. The pressure relief path is preferably of fluidic parallel configuration. In the embodiment which is shown here, merely one pressure relief device 200 is provided on the pressure vessel 100. A plurality of pressure relief devices 200 which can be activated thermally can likewise be provided on the pressure vessel 100. For example, in each case one pressure relief device 200 which can be activated thermally can be provided at each end. If a thermal event then occurs in the passenger interior compartment I or in the trunk K, the temperature of the triggering medium in the internal volume 211 can rise to a temperature which lies above the limit temperature (for example, 500° C.). If this is the case, the pressure in the internal volume 211 in one refinement can rise to such an extent that the closure 216 which is configured as a rupture disk is destroyed. The triggering medium which is then heated to a pronounced extent flows out of the pressure relief trigger 210 on account of gravity and/or a pressure difference between the triggering medium and the surrounding area, and is directed by way of the triggering medium channel 214 onto the opening element of the pressure relief device 200 which can be activated thermally. The triggering medium which has previously been heated by way of the thermal event outputs a part of the thermal energy to the opening element in the case of flowing onto or around the opening element. As a result, the opening element is heated to such an extent that the temperature of the opening element rises to a value which lies above the triggering temperature. In this way, the opening element is activated thermally. If, for example, a fusible link is provided, the fusible link melts and releases the pressure relief flow path of the pressure relief device 200 directly or indirectly. In comparison to the previously known solution, the thermal energy from the passenger interior compartment I or trunk K is therefore guided more rapidly and more directly to the TPRD. The TPRD can therefore trigger more rapidly and more reliably. In this way, the fuel can escape reliably before the fiber reinforced layer 120 is weakened by way of the thermal energy which is transmitted by way of the vehicle body floor element 300 to the fiber reinforced layer 120.

[0047] In the following description of the alternative exemplary embodiment which is shown in FIG. 2, identical designations are used for features which are identical and/or at least comparable in terms of their configuration and/or method of operation in comparison with the first exemplary embodiment which is shown in FIG. 1. Unless they are described in detail once again, their configuration and/or method of operation corresponds to the configuration and/or method of operation of the features which have already been described above.

[0048] FIG. 2 shows a pressure vessel 100 and a vehicle body floor element 300 which can be configured in the same way as has been described in conjunction with FIG. 1. In a deviation here, the pressure relief trigger 210 is configured as a triggering line 217. Here, the triggering line 217 protrudes into the shell region of the pressure vessel. The triggering line 217 is set up to detect a thermal event in the shell region directly or indirectly, and to bring about the triggering of the pressure relief device 200 which can be activated thermally. For example, the triggering line 217 can be filled with a triggering medium which increases or reduces the pressure in the triggering line 217 in a manner which is dependent on the temperature. The triggering line 217 might likewise be a fuse or a heat pipe. The specific configuration of the triggering line 217 and the pressure relief device 200 can be any suitable configuration, in so far as, in particular, a thermal event immediately adjacently with respect to the triggering line 217 is detected by means of the triggering line 217 directly or indirectly, and in so far as the triggering line 217 is set up such that, in the case of the triggering temperature of the triggering line 217 being exceeded adjacently with respect to the thermal event, the triggering line 217 brings about the pressure relief by means of the pressure relief device 200. In accordance with the technology disclosed herein, a triggering line 217 of this type or an element which is connected operatively to it (here, is connected fluidically to it) can then be guided at least partially through the vehicle body floor element. For example, the hose or the pipe can run partially through the passenger interior compartment I and/or the trunk K. In the example which is shown here, an element (here, a head part) of the triggering line 217 opens into the passenger interior compartment I or trunk K. If a thermal event then occurs in the passenger interior compartment I or trunk K, the triggering medium in the head part is heated to a temperature above the triggering temperature. This brings about a pressure relief by means of the pressure relief device 200. The mechanism as disclosed in the German patent application with the application number DE 10 2018 203183 can be used, for example, as a pressure relief mechanism. The disclosure of DE 10 2018 203183 with regard to the pressure relief mechanism is hereby also incorporated by reference. By way of a configuration of this type, it is possible to detect thermal events at different locations.

[0049] For reasons of readability, the term “at least one” has been partially omitted for simplicity reasons. In so far as a feature of the technology disclosed herein is described in the singular or with an indefinite article (for example, the/a pressure vessel, the/a pressure relief trigger, the/a vehicle body floor element, the/a fiber reinforced layer, the/a liner, the/a opening element, etc.), its plurality is also intended to be disclosed at the same time (for example, the at least one pressure vessel, the at least one pressure relief trigger, the at least one vehicle body floor element, the at least one fiber reinforced layer, the at least one liner, the at least one opening element, etc.).

[0050] In the context of the technology disclosed herein, the term “substantially” (for example, “substantially perpendicular axis”) comprises in each case the precise property or the precise value (for example, “perpendicular axis”) and in each case insignificant deviations for the function of the property/the value (for example, “tolerable deviation from a perpendicular axis”).

[0051] The preceding description of the present invention serves merely for illustrative purposes and not for the purpose of the restriction of the invention. Within the context of the invention, various amendments and modifications are possible without departing from the scope of the invention and its equivalents.