Abstract:
Provided is a battery cell protection device for a vehicle equipped with a battery pack composed of battery cells and a battery management system that manages power of the battery pack. In particular, the battery cell protection device includes a wiring harness accommodating a plurality of wires connecting the battery cell with the battery management system; and fuses disposed on the wires of the wiring harness. These fuse are configured to be cut by an abnormally high voltage so that when an external impact or shock is applied to the cell module, ignition of an explosion due to a short circuit in the wires connected with the batter cells is precluded, thereby ensuring driver and passenger safety.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority to Korean Patent Application Number 10-2011-0064709 filed Jun. 30, 2011, the entire contents of which application is incorporated herein for all purposes by this reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a battery cell protection device for an eco-friendly vehicle such as an electric vehicle or a hybrid vehicle, and more particularly, to a battery cell protection device of an eco-friendly vehicle that can prevent damage to the battery cell by shutting out abnormally high voltage from the battery cell. 
         [0004]    2. Description of Related Art 
         [0005]    Recently, eco-friendly vehicles equipped with a battery (i.e., hybrid vehicles and electric vehicles etc.) have become a significant market for most automotive manufacturers. In these eco-friendly vehicles, the capacity of batteries has been gradually increased to improve fuel efficiency and traveling performance of the cars as a whole. With the increase in capacity of the batteries, technologies for ensuring safety against high voltage have been developed as a result. The car manufacturers and battery manufacturers have reinforced the specifications of vehicles and items within these vehicles in order to prevent explosion due to a collision and/or electric short. 
         [0006]    One technology for protecting a battery cell against high voltage is employ a receptacle that is fixed to each of plurality of cell pouch electrodes to sense voltage and a connector that can sense voltage. The voltage sensing connector is disposed at a wiring harness connected with the electrode of the battery. In this technology, when the voltage sensing line in a cell module is disconnected by damage to the coating due to a car collision or a shock, the BMS (Battery Management System) diagnoses the disconnection. However, currently it is impossible to completely prevent a battery cell from exploding. Furthermore, in an electric vehicle or a plug-in battery, since the cell capacity is larger than in the existing hybrid vehicles [HEV], there is an even greater danger associated with an explosion. 
         [0007]    The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    The present invention has been made in an effort to provide a battery cell protection device for an eco-friendly vehicle that can ensure human safety by precluding igniting an explosion due to a short circuit in a wire connected to the battery cell, when an external impact or shock is applied to the cell module. In particular, an exemplary embodiment of the present invention provides a battery cell protection device of an eco-friendly vehicle, in a battery for a vehicle equipped with a battery pack that is composed of battery cells and a battery management system that manages power of the battery pack. The battery cell protection device includes: a wiring harness accommodating a plurality of wires connecting the battery cell with the battery management system; and fuses disposed on the wires of the wiring harness and broken by abnormally high voltage, in which the fuse is bonded to both opposite ends of the wire. 
         [0009]    More specifically, the wiring harness may include a plurality of high-voltage wires separately disposed, lead wires connected with the high-voltage wires by the fuses, and retracting tubes covering and fixing the high-voltage wires, the lead wires, and the fuses. The wiring harness may be disposed at a lower side of the battery pack to be replaceable. The thickness of the fuse may be about 2.3 mm to 2.5 mm. An insulator may be disposed between the fuses. 
         [0010]    The present invention has the advantage of being able to ensure human safety by precluding ignition of an explosion due to a short circuit in a wire connected with a battery cell, when an external impact or shock is applied to a cell module. 
         [0011]    The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a schematic enlarged view of a battery cell protection device of an eco-friendly vehicle according to an exemplary embodiment of the present invention. 
           [0013]      FIG. 2  is a view schematically showing the configuration of a wiring harness of  FIG. 1 . 
           [0014]      FIG. 3  is a circuit diagram of a battery cell protection device of an eco-friendly vehicle according to an exemplary embodiment of the present invention. 
           [0015]      FIG. 4  is a view showing when a short circuit has occurred in  FIG. 3 . 
           [0016]      FIG. 5  is a view showing a cartridge type fuse according to an exemplary embodiment of the present invention. 
           [0017]      FIG. 6  is a view showing a blade type fuse according to an exemplary embodiment of the present invention. 
           [0018]      FIG. 7  is a perspective view showing a voltage sensing line of a battery pack where the cartridge type fuse and the blade type fuse according to an exemplary embodiment of the present invention can be applied. 
           [0019]      FIG. 8  is a view showing a modified example of the battery cell protection device according to an exemplary embodiment of the present invention, in which a PCB is additionally provided. 
           [0020]      FIG. 9  is an enlarged view of the portion A shown in  FIG. 8 . 
       
    
    
       [0021]    It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment. 
         [0022]    In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims. 
         [0024]    It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g., fuels derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles. 
         [0025]    Referring to  FIGS. 1 to 3 , a battery cell protection device of an eco-friendly vehicle according to an exemplary embodiment may include a fuse  120  that protects a battery cell by shutting off or cutting the current accompanying high voltage between a battery pack  100  including a battery cell  102  and a battery management system  105  that manages the power of battery pack  100 . The fuse  120  may be disposed within a plurality of wires  115  disposed in a wiring harness  110  connecting the battery cell  102  with the battery management system  105 . Unlike that shown in the figure, about nine wires  115  may be disposed in the wiring harness  110 . The fuse  120  provides an electrical connection structure for the wires  115  vertically arranged and can shut off current flowing to the battery cell  102  by being “cut” when an abnormally high voltage is generated and received. 
         [0026]    The fuse  120  may be made of lead that can be melted and broken under an abnormally high voltage, in the wires  115  of the wiring harness  110 , and may be disposed within the device by bonding the fuse  120  at both opposite connection ends with the wire  115 . One or more fuses  120  may be disposed for each wire  115 , and an insulator (not shown) may be disposed between the fuses. Alternatively, the fuse(s)  120  may be coated with an insulator (not shown), so that it is possible to prevent a short circuit between fuses  120 . 
         [0027]    High voltage that can break or cut each of the fuses  120  may be generated when a short circuit occurs in any portion of the wiring harness  110  connecting the battery pack  100  with the battery management system  105  during normal operation of the battery in a vehicle. The short circuit between the battery pack  110  and the battery management system  105  may be generated by an impact or a shock due to an accident, may be generated when the coating on the wires  115  is slightly stripped off by heat due to overload, or may be generated when overvoltage is rapidly applied to battery management system  105 . 
         [0028]      FIG. 2  is a view schematically showing the configuration of wiring harness  110  of  FIG. 1 . Referring to  FIG. 2 , the wiring harness  110  may include a plurality of high-voltage wires  130  that are separately disposed, lead wires  131  connected to high-voltage wires  130  by the fuses  120 , and contacting tubes  135  that cover and fix the high-voltage wires  130 , the lead wires  131 , and the fuses  120 . The high-voltage wire  130  of the wiring harness  110  may have a dimension that makes it possible to sufficiently transmitting power from the battery pack  100  while the lead wire  131  and the fuse  120  may have a diameter and a thickness that can withstand common voltage. For example, the fuse  120  may be 2.3 mm to 2.5 mm thick. The contracting tube  135  is made of a material that can be contracted by heat and can fix and protect the high-voltage wire  130 , the lead wire  131 , and the fuse  120  in the wiring harness  110  and can provide insulation as well. 
         [0029]    Referring to  FIG. 1 , the wiring harness  110  may be disposed on a lower side of battery pack  100  to be easily replaced, such that it can be replaced at any time when the fuse  120  is broken or cut because the connector (not shown) is disposed as a plug-in module on both sides. 
         [0030]      FIG. 3  is a circuit diagram of a battery cell protection device of an eco-friendly vehicle according to an exemplary embodiment of the present invention.  FIG. 4  is a view showing when a short circuit has occurred in  FIG. 3 . 
         [0031]    Referring to  FIGS. 1 ,  3 , and  4 , a short circuit may occur in any wire  115  of the wires  115  in the wiring harness  110  between the battery pack  110  and the battery management system  105  and a high voltage may be applied to the fuse(s)  120  connecting the wires  115 . One or more of the fuses  120  may be cut/broken via a high voltage and the internal circuit of the battery cell  102  and the battery management system  105  can be protected from the high voltage by disconnecting the battery pack  100  from the battery pack management system  105  in the circuit diagram. As current is shut off to the wiring harness  110 , a fire that may be generated from wires  115  of wiring harness  110  can be prevented. 
         [0032]      FIG. 5  is a view showing a cartridge type fuse according to an exemplary embodiment of the present invention. A cartridge type fuse  120   a  may be disposed and protected in a receptacle connected with the battery pack. The cartridge type fuse  120   a  may be provided with a wire  121  on both sides, which is connected with the receptacle (not shown). 
         [0033]      FIG. 6  is a view showing a blade type fuse  120   b  according to an exemplary embodiment of the present invention. The blade type fuse  120   b  is provided with an electrode  122  on both sides, which is connected with the battery pack, and can be cut or broken inside. 
         [0034]      FIG. 7  is a perspective view showing a voltage sensing line of a battery pack where the cartridge type fuse and the blade type fuse according to an exemplary embodiment of the present invention can be applied. The ‘a’ is a voltage sensing terminal of the battery pack, the ‘b’ is a battery cell terminal tap, and the ‘c’ is a voltage sensing connector. The ‘d’ is a supply line connected with the battery pack, where a cartridge type fuse or a blade type fuse may be applied. 
         [0035]    Alternatively, as a modified example according to an exemplary embodiment of the present invention, as shown in  FIG. 8 , a PCB (Printed Circuit Board) with a fuse may be connected one side of the battery pack  100 . The PCB  140 , as shown in  FIG. 9 , may include a bus bar  144  and a voltage sensing connector  146  for connecting a substrate  142  with the electrode of the battery pack  100 . 
         [0036]    The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.