SYSTEM FOR PROTECTING A BATTERY SET IN AN ELECTRIC VEHICLE

Abstract

A system 200 for protecting a battery pack 106 in an electric vehicle during a lateral impact comprises an intruder 214, an actuator 206 coupled to the intruder 214, and an impact sensor 202. When a lateral impact above a predefined impact threshold is detected by the impact sensor 202, the intruder 214 is actuated to push the cross member 102 upwards, causing the cross member 102 to bulge upwards rather than downwards due to the lateral impact. This induces a weak point on the cross member 102, thus preventing penetration of the cross member 102 into the battery pack 106.The actuator 206 is a pyrotechnic device, and the predefined impact value is chosen so that the triggering of the pyrotechnic device is delayed in order to ensure sufficient deformation of the side sill 110 and thus the transfer of the impact force to the cross members 102.

Description

TECHNICAL FIELDThe present disclosure relates to the field of electric vehicles. More particularly, the present disclosure relates to the safety of a battery pack of the electric vehicle during a transverse impact.BACKGROUNDThe background description contains information that may be useful for understanding the present disclosure. It is not an admission that the information contained herein belongs to the prior art or is relevant to the present disclosure, or that a publication expressly or implicitly referred to belongs to the prior art.Currently, electric vehicles are gaining popularity over conventional internal combustion engine vehicles because they are environmentally friendly and have lower operating costs. A battery pack for powering the vehicle is typically located below an upper vehicle floor, the floor structure comprising one or more cross members. In a side impact, such as simulated by a side pile impact, the cross members tend to flex in the Z direction and enter the battery pack, leading to damage to the battery cells and possibly a risk of fire.In the interest of safety, it would therefore be better to have a system that minimizes the adverse effects of a side impact on the battery pack.The patent document DE102013005099A1 discloses a deformation element for vehicles, which can be fastened to a supporting element of the vehicle and has such a structure that in the event of an impact, e.g. an accident or a high-speed impact or a pedestrian accident, at least a part of the deformation element moves in a direction other than the impact direction and thereby protects the supporting element from the impact.While the cited reference discloses a structure for protecting a supporting member of a vehicle, it is possible to provide an improved system and method for protecting the battery pack of an electric vehicle from a side impact.There is therefore a need to provide a simple, easy to install and low cost solution for protecting the battery pack in a side impact in an electric vehicle.OBJECTS OF DISCLUSCHA general object of the present disclosure is to improve safety of electric vehicles.An object of the present disclosure is to improve the safety of electric vehicles by providing a system and method that minimizes the adverse effects of a side impact on the electric vehicle battery pack.Another object of the present disclosure is to provide a simple, easy to install, and low cost solution to prevent intrusion of a floor cross member into the battery pack during a side impact.SUMMARYAspects of the present disclosure relate to the safety of high voltage battery packs in electric vehicles. In particular, the present disclosure provides a system and method that minimizes the adverse effects of a side impact on the battery pack by preventing intrusion of a floor cross member (also referred to herein simply as a cross member) of a floor structure of the vehicle under which the battery pack is disposed. In one aspect, the disclosed system and method prevent intrusion of the floor cross member into the battery pack by bending the cross member upward rather than downward during a side impact.In one aspect, the proposed system for protecting a battery pack in a vehicle during an impact includes an indenter configured below a floor cross member of the vehicle; and an actuator coupled to the indenter such that when the actuator is activated, the indenter presses against the floor cross member from below to apply a force to the floor cross member. The system further includes an impact sensor to detect occurrence of a side impact, and in the event that the impact detector detects a side impact, the actuator is activated to push the indenter to induce an upward deflection in the floor cross member, such that deformation of the floor cross member due to the impact force from the side impact occurs in an upward direction, thereby preventing downward deformation of the floor cross member and resultant intrusion of the floor cross member into the battery pack.In one or more embodiments, the actuator may be a pyrotechnic device having an igniter and a propellant located in a tubular passage. When the impact sensor detects a transverse impact above a predefined impact value, the initiator of the pyrotechnic device is actuated to move the propellant and push the indenter upward. The upward movement of the indenter causes the indenter to impact the floor cross member and bulge the floor cross member subjected to the transverse impact by the impact in the upward direction rather than in the downward direction by inducing a weak spot on the floor cross member.In one or more embodiments, the floor cross member may be configured such that the body shell is located above the battery pack.In one or more embodiments, the indenter may be disposed in a tubular passage below the floor cross member of the body shell.In one or more embodiments, the impact sensor may be an ultrasonic impact sensor that sends a signal to the ignition device when the quantum of the side impact exceeds the predefined impact value.In one or more embodiments, the predefined impact value may be selected to delay deployment of the pyrotechnic device to ensure sufficient deformation of the side sill of the BiW and thus transmission of the impact force to the floor cross members.Another aspect of the disclosure relates to a method of protecting a battery pack in a vehicle during an impact, comprising the steps of: (i) detecting a transverse impact on the vehicle by an impact sensor; (ii) checking whether the transverse impact is above a predefined impact value; and (iii) actuating a detonator of a pyrotechnic device when it is determined that the transverse impact is above a predefined impact value. In one aspect, the actuation of the igniter results in a indenter being pressed to induce an upward deflection into the floor cross member such that the deformation of the floor cross member due to the impact force by the side impact occurs in an upward direction, thereby preventing a downward deformation of the floor cross member and a resulting penetration of the floor cross member into the battery pack.In one or more embodiments, the method may further comprise the step of disposing the indenter in a tubular passage below the floor cross member.In one or more embodiments, the method may further comprise the step of disposing the igniter and an indenter of the pyrotechnic device in the tubular passage behind a seal such that igniting the igniter results in burning of the indenter and the resulting gas pushes the indenter toward the floor cross member.Various objects, features, aspects and advantages of the subject matter of the invention will become more apparent from the following detailed description of preferred embodiments, taken in conjunction with the accompanying drawing figures, in which like numerals represent like components.BRIEF DESCRIPTION OF THE DRAWINGSThe accompanying drawings serve to further understand the present disclosure and form part of this description. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. FIGS. 1A and 1B show schematic representations of a cross impact on a vehicle, e.g., by a rod, causing a floor cross member to buckle downward, thereby penetrating the battery pack and compromising the safety of the vehicle. FIG. 2 shows an example block diagram for the proposed system for protecting a battery pack in an electric vehicle during a side impact, in accordance with embodiments of the present disclosure. FIG. 3A shows an example schematic cross-sectional view illustrating the arrangement of an indenter and a pyrotechnic device-based actuator of the system of FIG. 2 below a cross member of the vehicle according to embodiments of the present disclosure. FIG. 3B shows an example schematic cross-sectional diagram illustrating the pyrotechnic device-based actuator in an actuated state according to embodiments of the present disclosure. FIG. 4 shows an example view of a likely upward deflection of the floor cross member caused by the cross impact of the vehicle after being pushed in an upward direction by the indenter, in accordance with embodiments of the present disclosure. FIG. 5 shows a method flow diagram defining the steps for protecting the battery pack in a vehicle during the cross crash according to embodiments of the present disclosure.DETAILED DESCRIPTIONThe following is a detailed description of the embodiments of the disclosure illustrated in the accompanying drawings. The embodiments are so detailed as to clearly convey the disclosure. However, it is not intended to limit the predictable variations of embodiments by way of detail; rather, all modifications, equivalents and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims are intended to be covered.The embodiments discussed herein relate to a system and method that minimize the adverse effects of a side impact on the battery pack by preventing intrusion of a floor cross member of a floor structure of the vehicle under which the battery pack is disposed. FIGS. 1A and 1B show a typical simulation of a side impact of a vehicle by a pile test in which a pile barrier 108 impacts the vehicle from a transverse side. As shown, the pile barrier 108 meets a side sill 110 of a floor structure 100 of the vehicle. The transverse impact on the rocker 110 is transmitted to one or more floor cross members, such as the floor cross member 102. As illustrated in FIG. 1B, the side sill 110 is damaged by the side impact, and the cross member 102 also warps. As illustrated by reference numeral 104, among the transmitted lateral / lateral impact forces acting on the cross member 102, they act in a longitudinal direction of the cross member 102.As shown in FIG. 1B, the buckling cross member 102 may bend downward and enter the battery pack 106 located below the cross member 102, thereby damaging the cells, which may have catastrophic consequences, such as a fire that presents a severe risk of life and property.As will be appreciated by those skilled in the art, the buckling of the cross member cannot be avoided because the buckling serves a useful purpose of absorbing the impact forces from the crash. Therefore, countermeasures against the aforementioned scenario are required to protect the battery pack 106 in electric vehicles, which prevent the kinked cross member from entering the battery pack.In one aspect, the disclosed system and method prevent intrusion of the floor cross member into the battery pack by bending the cross member in an upward direction instead of the downward direction during a side impact, wherein the upward bending is initiated by application of a timely upward force to the cross member that causes the side impact force from the side crash / impact to bend the cross member in the upward direction.In one embodiment, the upward force is applied to the cross member by an indenter pressed against the cross member in an upward direction by an actuator. In another embodiment, the actuator is a pyrotechnic device that is actuated based on an actuation signal (also referred to herein simply as a signal) from an impact sensor. In another embodiment, the impact sensor is configured to send the actuation signal to the actuator based on the pyrotechnic device when the side impact goes beyond a predefined impact value, the predefined impact value being selected to ensure that an appropriate force acts on the cross member to begin buckling of the cross member, and that application of the upward force by the indenter to the cross member at that point causes a directed upward buckling instead of a random downward buckling, which could be a downward buckling, thereby penetrating the cross member into the battery pack.Referring to FIG. 2, which discloses an example block diagram for the proposed system 200 for protecting a battery pack in an electric vehicle during a side impact (216), the system 200 may include an indenter 214, an actuator 206 coupled to the indenter 214, and an impact sensor 202. The system may also include an electronic control unit (ECU) 204.In one embodiment, the impact sensor 202 may be an ultrasonic impact sensor that transmits a signal directly to the initiator 208, or other types that transmit the signal via the electronic control unit 204 configured with the vehicle. The controller 204 may be configured to receive the impact signal from the impact sensor 202, analyze the impact signal to determine the value of the impact, and send a trigger signal to the actuator 206 when the quantum of the side impact exceeds a predefined impact value.As can be seen from FIGS. 3A and 3B, in one embodiment, the actuator 206 may be a pyrotechnic container (the term actuator is also referred to as a pyrotechnic device, and the two terms are used interchangeably herein). The pyrotechnic device includes an igniter 208 and a propellant 210. The fuel may be sealed in a tubular passage 212 by a seal 302. The indenter 214 may also be located within the tubular passage 212, which may be defined by a tubular structure.In one embodiment, the indenter 214 is disposed in the BIW below the cross member 102, for example in a tubular passage 212 (see FIGS. 3A and 3B ), such that it can slide upward and strike the floor cross member 102 from below.In one embodiment, the operation of the actuator 206 is controlled by the impact signal transmitted from the impact sensor 202 to the igniter 208 via the electronic control unit 204. In some embodiments, the actuation signal may be directed from the impact sensor 202 directly to the igniter 208 depending on the type of the impact sensor 202. The igniter 208 may include explosive engines to ignite the propellant 210 to actuate the indenter 214. When the igniter 208 ignites the propellant 210, the propellant 210 burns to create a high volume of gas that fills the tubular passage 212, thereby breaking the propellant 210 open the seal 302, as shown by reference numeral 304 in FIG. 3B, to pass behind the indenter 214 and propel the indenter 214 within the tubular passage 212 toward the cross member 102. The high pressure of the gases generated by the combustion of the propellant 210 causes the indenter 214 to impact the cross member 102 with a force that causes the generated cross impact force in the cross member 102 to deform the cross member 102 upward. A directed deformation thus prevents a downward deformation of the cross member 102.In one embodiment, the trigger signal is sent to the initiator 208 when the magnitude of the impact exceeds a predefined impact value, thereby ensuring that sufficient transverse impact force is built up in the cross member 102 at the time the indenter 214 impacts the cross member 102 to cause the cross member 102 to begin buckling.FIG. 4 shows an example view in which the cross member 102 is bent upward due to directional deformation 402 due to the transverse impact of the vehicle protecting the battery pack 106.FIG. 5 shows a method flow diagram 500 defining the steps for protecting the battery pack 106 in a vehicle during the transverse impact.In one embodiment, the method 500 of protecting a battery pack, such as the battery pack 106 shown in FIG. 1B, in a vehicle during an impact includes the step 502 of detecting a transverse impact on the vehicle by an impact sensor, such as the impact sensor 202 shown in FIG. 2, due to the occurrence of a side impact ( 216). In step 504, the method 500 may include checking if the cross impact is above a predefined impact value.In one embodiment, the method 500 includes, at step 506, upon detecting the cross impact that is above a predefined impact value, actuating the initiator of the actuator 206, such as the initiator 208 shown in FIGS. 2-3B.In one embodiment, in performing step 506 of igniting the igniter 208, the indenter 214 is pressed to cause upward deflection 402 of the floor cross member 102 such that the deformation of the floor cross member 102 due to the impact force by the side impact (216) occurs in an upward direction, thereby preventing downward deformation of the floor cross member 102 and consequent penetration of the floor cross member 102 into the battery pack 106.In one embodiment, the method 500 may further include the step of disposing the indenter 214 in a tubular passage 212 located below the floor cross member 102.In one embodiment, the method 500 may further include the step of disposing the igniter 208 and a propellant 210 in the tubular passage 212 behind a seal 302 such that igniting the igniter 208 results in burning of the propellant 210 and the resulting gas forces the indenter 214 toward the floor cross member 102.Therefore, the present disclosure provides a system and method that enhances the safety of an electric vehicle in a side impact by minimizing the likelihood of a floor cross member entering the high voltage battery of the electric vehicle. In particular, the system and method of the present disclosure utilize directional buckling / bending of the floor cross member to cause the cross member to flex upward rather than potentially bending downward. The disclosure provides a simple, easy to install, and low cost solution for guiding the upbend 402 of the floor cross member 102, which results in the safety of the battery pack 106 and ultimately protects the occupants of the electric vehicle.While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope of the invention. The scope of the invention is defined by the following claims. The invention is not limited to the described embodiments, versions or examples included to enable a person of ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person of ordinary skill in the art.ADVANTAGES OF THE DISCLOSUREThe present disclosure provides a system and method that improves the safety of electric vehicles.The present disclosure provides a system and method that minimizes the adverse effects of a side impact on the battery pack of an electric vehicle.The present disclosure provides a simple, easy to install, and low cost solution to prevent floor cross member intrusion into the battery pack during a side impact.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 102013005099A1

[0005]

Claims

A system (200) for protecting a battery pack (106) in a vehicle during an accident, the system (200) comprising: an indenter (214) disposed below a floor cross member (102) of the vehicle; and an actuator (206) coupled to the indenter (214) such that when the actuator (206) is activated, the indenter (214) presses from below against the floor cross member (102) to apply a force to the floor cross member (102); and an impact sensor (202) to detect the occurrence of a side impact (216); wherein, in the event that the impact sensor (202) detects a side impact (216), the actuator (206) is activated to push the indenter (214) to induce an upward deflection in the floor cross member (102), such that deformation of the floor cross member (102) due to the impact force from the side impact (216) occurs in an upward direction, thereby preventing a downward deformation of the floor cross member (102) and a consequent intrusion of the floor cross member (102) into the battery pack (106).The system of claim 1, wherein the actuator (206) is a pyrotechnic device comprising an igniter (208) and a propellant (210) coupled to the indenter (214):), wherein actuation of the igniter (208) results in the indenter (214) being pressed to cause an upward deflection (402) in the floor cross member (102), such that deformation of the floor cross member (102) due to the impact force by the side impact (216) occurs in an upward direction, thereby preventing downward deformation of the floor cross member (102) and consequent intrusion of the floor cross member (102) into the battery pack (106).The system of claim 1, wherein the floor cross member (102) with the body shell is disposed above the battery pack (106).The system of claim 1, wherein the indenter (214) is disposed in a tubular passage (212) below the floor cross member (102) of the body shell.The system of claim 2, wherein the impact sensor (202) is an ultrasonic impact sensor that sends a signal to the initiator (208) when the quantum of the side impact exceeds the predefined impact value.The system according to claim 5, wherein the predefined impact value is chosen so as to delay the deployment of the pyrotechnic device to ensure sufficient deformation of the side sill (110) of the BiW and thus the transmission of the impact force to the floor cross members (102).A method (500) of protecting a battery pack (106) in a vehicle during an accident, the method (500) comprising the steps of: detecting (502), by a crash sensor (202), a transverse impact on the vehicle due to a side crash (216); checking (504) whether the transverse impact is above a predefined impact value; and actuating (506) a pyrotechnic device initiator (208) when it is detected that the transverse impact is above a predefined impact value; wherein the actuation of the igniter (208) results in a indenter (214) being pressed to cause an upward bend (402) in the floor cross member (102), such that deformation of the floor cross member (102) due to the impact force by the side impact (216) occurs in an upward direction, thereby preventing downward deformation of the floor cross member (102) and consequent penetration of the floor cross member (102) into the battery pack (106).The method (500) of claim 7, comprising the step of disposing the indenter (214) in a tubular passage (212) located below the floor cross member (102).The method (500) of claim 8, comprising the step of configuring the igniter (208) and a propellant (210) in the tubular passage behind a seal (302) such that igniting the igniter (208) results in burning of the propellant (210) and the resulting gas forces the indenter (214) toward the floor cross member (102).

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