Method for responding to a fire-critical battery state in a vehicle, and a vehicle designed to carry out such a method

Abstract

A method for responding to a fire-critical battery state in a motor vehicle having at least one battery, and a motor vehicle designed to carry out such a method. A battery temperature of the at least one battery of the motor vehicle is continuously detected by at least one temperature sensor. The method includes the following steps: Continuous detection of a temperature change in the battery based on the continuously detected battery temperature; verifying whether the detected temperature change exceeds a specified threshold defining a fire-critical battery state; and activating at least one vehicle function in order to perform a protective and/or warning measure by a control unit, if the fire-critical battery state is reached.

Claims

1. A method for responding to a fire-critical battery state in a motor vehicle having at least one battery, wherein a battery temperature is continuously detected by at least one temperature sensor, comprising the following steps: continuously detecting of a temperature change of the battery based on the continuously detected battery temperature; verifying whether the detected temperature change exceeds a specified threshold defining a fire-critical battery state; actuating at least one vehicle function for carrying out a protective measure and/or warning measure by a control device, if the fire-critical battery state is reached; wherein the battery is enclosed by a battery housing, which has a degassing vent at a location leading into a trunk of the vehicle, and a burst opening with an exit point outside an area of a passenger occupancy area of the vehicle wherein, as the protective measure, the following measures are carried out in the vehicle: activating a safety mode of an air conditioner by deactivating the air conditioner or operating the air conditioner in recirculation mode without ventilation function; door release; automatic closing of opened vehicle windows and or of an opened vehicle moonroof; and interrupting a power supply for an electric drive unit of the motor vehicle; and wherein the following measures are carried out as the warning measure: automatically activating a hazard warning light; and placing an automatic emergency call to a specified control center; displaying a warning signal in the vehicle interior.

2. The method according to claim 1, wherein, checking whether the continuously detected battery temperature exceeds a specified threshold temperature, which defines the fire-critical battery state.

3. The method according to claim 1, wherein local battery temperatures are continuously detected by several temperature sensors, a spatial temperature gradient is determined on the basis of the continuously detected battery temperatures, and checking whether the determined spatial temperature gradient exceeds a specified gradient threshold, which defines the fire-critical battery state.

4. A motor vehicle comprising: a battery, at least one temperature sensor for continuously detecting a battery temperature and a control device for actuating at least one vehicle function of the motor vehicle, wherein the control device is designed to carry out a method according to claim 1.

5. The motor vehicle according to claim 4, wherein the battery has several battery cells and is designed to supply power to an electrical drive unit of the motor vehicle.

6. The motor vehicle according to claim 4, wherein a fire protection layer is arranged between the battery and the vehicle interior.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) Below follows a description of an embodiment of the invention. For this purpose, the FIGURE shows a schematic representation of a vehicle with a battery, which is in a fire-critical battery state.

DETAILED DESCRIPTION

(2) The exemplary embodiment explained below represents a preferred embodiment of the invention. In the exemplary embodiment, each of the described components of the embodiment represents individual functions of the invention, which should be considered independently of one another, and which further develop the invention independently of one another. Therefore, the disclosure should include combinations of functions of the embodiment in addition to those described. Furthermore, the described embodiment may also be supplemented by already described additional functions of the invention.

(3) In the FIGURE, identical reference numerals denote functionally equivalent elements.

(4) In the one FIGURE, a motor vehicle 1 is outlined, i.e., a battery 3 designed to supply power to an electric drive unit (not shown) of the vehicle 1. The battery 3 shown here is, e.g., a so-called traction battery based on lithium-ion technology, i.e., battery 3 comprises several battery cells 4 and a battery housing 5. Several temperature sensors 6 are arranged within the battery housing 5, each of which detects a battery temperature on a continuous basis.

(5) A fire protection layer 8 is arranged between the battery case 5 and the vehicle interior 7. This fire protection layer 8 is, e.g., a fire protection mat or other fire-retardant material. The vehicle interior 7 is also separated by means of a dividing wall 10 from the trunk 9 of the motor vehicle 1.

(6) There are two occupants 11 in motor vehicle 1. When actually driving the motor vehicle 1, one of the vehicle 1 windows 12 is half open and an automatic door lock has locked the door locks 13 of motor vehicle 1. For automatic control of the vehicle windows 12 and the door locks 13, the motor vehicle 1 comprises a window control 15a and a door locking system 15b. A vehicle light control unit 15c is outlined here as a further vehicle function 15. The three mentioned vehicle functions 15a, 15b, 15c are designed to be controlled by a control unit 14 of the vehicle 1. Here, the vehicle light control unit 15c is especially designed to activate the vehicle lights of motor vehicle 1 as hazard warning lights 16.

(7) The control unit 14 continuously determines a temperature change of battery 3 based on the continuously detected battery temperature. Thus, the change of the battery 3 temperature over time is repeatedly detected. The control unit 14 then verifies whether the determined temperature change exceeds a specified threshold, which defines a fire-critical battery state. Alternatively or in addition to the determined temperature change, the continuously detected battery temperature itself may also be adjusted with a preset threshold temperature. Alternatively or in addition, a spatial temperature gradient may be continuously detected by using the local battery temperatures as determined by several temperature sensors 6. This spatial temperature gradient may be compared with a specified gradient threshold.

(8) The fire-critical battery state is also reached, when the continuously detected battery temperature exceeds the specified threshold temperature and/or the spatially determined temperature gradient exceeds the specified gradient threshold. The fire-critical battery state is thus defined on the basis of a remarkably large temperature change and/or an increased battery temperature and/or an increased spatial temperature gradient.

(9) If the fire-critical battery state has been reached, at least one of the vehicle functions 15 is activated in order to carry out a protective measure or a warning measure. This activation of the vehicle functions 15 is done by means of control unit 14.

(10) As a protective measure, automatic unlocking the door locks 13 of the motor vehicle 1 may, for example, take place. Thus, a corresponding control command is transmitted to the door locking system 15b via control unit 14. This enables the occupants 11 to escape from vehicle 1 and facilitates recovery of the occupants 11 of vehicle 1 by called-in rescue and salvage personnel.

(11) As a further protective measure, automatic closing of the open vehicle window 12 may also take place via appropriate control commands from control unit 14 to the window control 15a. Further possible protective measures include activating the safety mode of an air conditioning system by deactivating the air-conditioning system or operating it in recirculation mode without ventilation function, or interrupting the power supply of the electric drive unit of motor vehicle 1.

(12) In addition to the two aforementioned protective measures, a warning measure is also carried out in this example. For this purpose, a corresponding control signal is transmitted from the control unit 14 to the vehicle light control unit 15c, which then activates the hazard warning lights 16 of motor vehicle 1. Alternatively or in addition, an automatic emergency call may be placed to a specified control center or a warning signal may be displayed in the vehicle interior 7, which, e.g., alerts the occupants 11 to leave vehicle 1 as quickly as possible if the battery 3 of vehicle 1 is in a fire-critical battery state.

(13) In addition or as an alternative to the fire protection layer 8, which may slow down or even prevent the development of a fire in the vehicle interior 7 as a result of a fire of the battery 3, the battery 3 has a degassing vent 17. The degassing vent 17 is located at a point in the battery 3 not facing the vehicle interior 7, but the trunk 9. If excess pressure in the battery 3 is reduced and/or flames and smoke escape through this degassing vent 17, this will not occur in the direction of the area of the motor vehicle 1, wherein the occupants 11 are located, but in the direction of the trunk 9, which may be loaded only with luggage, which further increases the protection of the occupants 11 to the extent possible.

(14) Alternatively or in addition to the degassing vent 17, a burst opening may be provided at the point of the battery 3 not facing the vehicle inferior 7.

(15) Generally, the example shows how for motor vehicle 1, a method for responding to a fire-critical battery state in vehicle 1 with at least one battery 3 can be carried out. In this case, occupants 11 of the motor vehicle 1 are informed about a fire-critical state in battery 3, i.e., warned with the aid of warning measures, whereupon measures to protect the occupants 11 are initiated.