Patent Publication Number: US-2016240833-A1

Title: Positive locking confirmation mechanism for battery contact of electric vehicle and positive locking confirmation device for electrode of battery pack

Description:
FIELD OF THE INVENTION 
     The present invention relates to a positive locking confirmation mechanism and a positive locking confirmation method for a terminal bolt of a battery pack in a battery box of an electric vehicle, and more particularly to a device of sensing the locking state of the terminal bolt. The positive locking confirmation method is applied to an electric vehicle because a great number of battery packs are connected with each other to provide electric power. The terminal bolts associated with the battery packs are influenced by the vibration of the electric vehicle. The individual battery packs are connected with a battery management unit to provide battery data to a vehicular controlling unit, and thus the influences are monitored by using the positive locking confirmation method. 
     BACKGROUND OF THE INVENTION 
     Generally, a battery pack of a large electric vehicle comprises several hundreds of batteries. These batteries are connected with each other in parallel or in series. However, if the battery contacts are not securely locked, the batteries of the battery pack are possibly loosened. Especially, when the electric vehicle is driven on a road with a poor condition, the vibration of electric vehicle may accelerate the problem of loosening the battery contacts. If the battery contacts are loosened or poorly contacted during the travelling process of the electric vehicle, the overall power system is possibly shut down or burnt out. 
     However, the conventional electrode connecting method cannot indicate whether the electrodes are certainly locked. If the battery pack is suffered from a poor contact problem, the worker cannot immediately realize the damaged site. Under this circumstance, the time period of checking the battery pack is largely increased. Moreover, since the electric vehicle is only powered by the battery pack, the reliability of the battery pack is an important factor influencing performance of the electric vehicle. 
     In comparison with gasoline vehicles and diesel vehicles, batteries are the only power sources of the electric vehicles. For acquiring the reliable power source, a feasible and reliable method of detecting the positive locking state of the terminal bolt of the electric vehicle is necessary. However, the method of detecting the positive locking state may use additional sensors or wires in the battery pack. Since the battery pack comprises plural batteries, the additional sensors or wires may increase the labor cost and the assembling complexity. In other words, the conventional method of detecting the positive locking state is not user-friendly. 
     Moreover, for connecting the electrodes of the battery pack of the electric vehicle, a voltage sensor (or a current sensor) and a conductive metal are locked on an electrode through a terminal bolt. Under this circumstance, the tasks of replacing the batteries or replacing the voltage sensor will be frequently done. Therefore, there is a need of providing an improved technology to overcome the above drawbacks. 
     SUMMARY OF THE INVENTION 
     For overcoming the drawbacks of the electrode of the battery pack of the conventional electric vehicle, the present invention provides a positive locking confirmation mechanism and a positive locking confirmation method. 
     The positive locking confirmation mechanism comprises a terminal bolt, a positioning bolt, a conductor, a voltage sensing contact and an electrode. The electrode comprises an electrode thread and a positioning thread. The terminal bolt is used for fixing the conductor on the electrode. The head portion of the terminal bolt comprises plural positioning recesses. During the process of installing the positive locking confirmation mechanism, one positioning recess of the terminal bolt is aligned with the positioning bolt. After the positioning bolt is screwed into the positioning thread through the positioning recess, the voltage sensing contact is fixed on the electrode. 
     Moreover, the positioning bolt is used for positioning the terminal bolt in order to confirm the positive locking state of the terminal bolt. Consequently, only when the positioning bolt is removed, the terminal bolt can be detached from the electrode or the location of the terminal bolt can be changed. 
     For detecting the locking states of all electrodes of the battery pack, a vehicular controlling unit performs a computing process to judge whether the voltage signal is stable. Once the voltage signal received by a specified voltage sensor is unstable, the vehicular controlling unit can sense the unstable voltage signal. Before the terminal bolt is not in the positive locking state, a task of checking the connection of the electrode corresponding to the voltage sensor needs to be performed. In particular, the vehicular controlling unit issues a warning prompt to notify the user to perform the connection checking task. After the connection checking task, the possibility of detaching the terminal bolt and the conductor from the electrode thread will be minimized. Consequently, the problems of generating electric arc or surge in the electric vehicle will be avoided. 
     An object of present invention provides a positive locking confirmation mechanism for increasing the efficacy of assembling the battery contacts and confirming the positive locking state of the battery contact in order to overcome the drawbacks of the conventional technology. Moreover, the positive locking confirmation mechanism can prompt the user to check the locking states of the electrodes of the large battery pack and issue a warning to the driver when the electrodes are possibly loosened. 
     Another object of present invention provides a warning means of issuing a warning signal when the electrode is possibly loosened. The warning signal can notify the maintenance worker to check and repair the battery pack. 
     Another object of present invention provides a positive locking confirmation mechanism for confirming the locking state according to a voltage signal of the battery pack that is sensed by a voltage sensor. Consequently, the fabricating cost is reduced. 
     Another object of present invention provides a positive locking confirmation mechanism for simplifying the process of assembling or disassembling the battery management unit with/from the battery packs. 
     In accordance with an aspect of the present invention, there is provided a positive locking confirmation mechanism for a battery contact of an electric vehicle. The positive locking confirmation mechanism includes an electrode, a terminal bolt, a positioning bolt and a sensing unit. The electrode includes an electrode thread and a positioning thread. The terminal bolt is locked on the electrode, so that a conductor is contacted with the electrode. A head portion of the terminal bolt comprises at least one positioning recess. The positioning bolt is screwed into the positioning thread, so that a sensing contact of a battery management unit is fixed on the electrode. When the positioning bolt is screwed into the positioning thread, the positioning bolt is partially received within the positioning recess. The sensing unit performs a computing process for determining whether the terminal bolt is in a positive locking state according to a result of judging whether a voltage signal from the sensing contact is stable. 
     In an embodiment, if the voltage signal is stable, the controlling unit judges that the terminal bolt is in the positive locking state. 
     In an embodiment, if the controlling unit senses that the terminal bolt is not in the positive locking state, the controlling unit issues an identification code to a user to prompt the user to check a connection status of the terminal bolt. 
     In an embodiment, the positioning bolt is made of an insulation material. 
     In an embodiment, a non-conductive coating is formed on a contact area between the sensing contact and the positioning bolt. 
     In an embodiment, the controlling unit further includes a gyroscope for sensing a vibration frequency of the electric vehicle. Moreover, the vibration frequency of the electric vehicle is compared with a waveform of the voltage signal. 
     In accordance with another aspect of the present invention, there is provided a positive locking confirmation device for an electrode of a battery pack. The positive locking confirmation device includes a terminal bolt, a positioning bolt and an electrode. The positive locking confirmation device performs a computing process to continuously detecting whether a voltage signal from a sensing contact is stable. When the positioning bolt is locked on the electrode and partially received within a positioning recess of the terminal bolt, the terminal bolt is not rotated and the sensing contact is fixed on the electrode. 
     The above contents of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic isometric view illustrating a positive locking confirmation mechanism according to an embodiment of the present invention; 
         FIG. 2  is a schematic exploded view illustrating a terminal bolt of the positive locking confirmation mechanism according to the embodiment of the present invention; 
         FIG. 3  is a schematic cross-sectional view illustrating a portion of the positive locking confirmation mechanism according to the embodiment of the present invention; 
         FIG. 4  schematically illustrates a wiring configuration of the positive locking confirmation mechanism according to the embodiment of the present invention; and 
         FIG. 5  is a schematic isometric view illustrating a variant example of the positive locking confirmation mechanism, in which the positive locking confirmation mechanism further comprises a safety clip. 
     
    
    
     Element numerals in the drawings is illustrated as follows:  101 , electrode;  102 , terminal bolt;  103 , positioning recess;  104 , sensing contact;  105 , positioning bolt;  108 , electrode thread;  114 , conductor;  115 , positioning thread;  410 , first battery pack;  420 , second battery pack;  430 , third battery pack;  440 , fourth battery pack;  450 , second battery management unit;  460 , first battery management unit;  403 , negative terminal connection point;  404 , positive terminal connection point;  491 , connection wiring of the negative terminal connection point  403 ; and  495 , connection wiring of the positive terminal connection point  404 . 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Hereinafter, a positive locking confirmation mechanism according to an embodiment of the present invention will be illustrated with reference to  FIGS. 1 to 3 . The positive locking confirmation mechanism comprises a terminal bolt  102 , a positioning bolt  105 , an electrode  101 , a conductor  114  and a voltage sensing contact. The electrode  101  comprises an electrode thread  108  for fixing the conductor  114  and the terminal bolt  102 . A head portion of the terminal bolt  102  comprises plural positioning recesses  103  for positioning the positioning bolt  105  in a positioning thread  115  of the electrode  101 . When the positioning bolt  105  is screwed into the positioning thread  115 , the sensing contact  104  of a battery management unit is fixed on the electrode  101 . Moreover, the positioning bolt  105  is received in one of the plural positioning recesses  103  in order to stop rotation of the terminal bolt  102 . 
     A process of installing the positive locking confirmation mechanism will be illustrated as follows. Firstly, the conductor  114  is placed on the electrode  101 . In addition, a perforation of the conductor  114  is aligned with the electrode thread  108 . Then, the terminal bolt  102  is screwed into the electrode thread  108 , and thus the conductor  114  is fixed between the terminal bolt  102  and the electrode thread  108 . Then, one positioning recess  103  of the terminal bolt  102  is aligned with the positioning thread  115 . After the positioning bolt  105  is screwed into the positioning thread  115 , the sensing contact  104  is fixed on the electrode  101 . Consequently, the installation of the positioning bolt  105  can confirm the positive locking state of the terminal bolt  102 . 
     In other words, the positioning bolt  105  is used to confirm the positive locking state of the terminal bolt  102 . In particular, the positioning bolt  105  stops the rotation of the terminal bolt  102  in order to confirm the positive locking state of the terminal bolt  102 . 
     The present invention further provides a positive locking confirmation method. In accordance with the positive locking confirmation method, the vehicular controlling unit performs a computing process to detect whether the voltage signal from the sensing contact of the battery management unit is stable. 
     In accordance with the positive locking confirmation mechanism of the prevent invention, for rotating the terminal bolt  102 , it is necessary to remove the positioning bolt  105 . Moreover, if the positioning bolt  105  is loosened because of the vibration of the electric vehicle, it means that the voltage signal is unstable or subjected to fluctuation. According to the unstable voltage signal, the vehicular controlling unit can recognize that the positioning bolt  105  is loosened. 
     In case that the sensing contact of the battery management unit is loosened from the terminal bolt of a specified battery pack and is not in the positive locking state, the voltage signal is unstable. Under this circumstance, the vehicular controlling unit accepts a connection check request and indicates the identification code of the battery pack to the user or the maintenance worker. Since the vehicular controlling unit prompts the connection status of the battery pack to the user or the maintenance worker, the problems of generating electric arc or causing power shutdown during the process of driving the electric vehicle will be avoided. 
     In accordance with the positive locking confirmation method of the present invention, the vehicular controlling unit continuously performs a computing process to judge whether the current signal or the voltage signal is stable. Preferably, for performing the computing process, a gyroscope is employed for sensing the vibration of the electric vehicle. If the waveform of the voltage signal detected by the vehicular controlling unit matches the vibration frequency of the electric vehicle, the vehicular controlling unit judges that the terminal bolt is no longer in the positive locking state. 
     More preferably, the positioning bolt is made of an insulation material. Consequently, the voltage sensor will not receive the voltage signal through the contact area between the sensing contact and the terminal bolt. Since the unstable voltage signal is amplified, the locking state can be detected in a more sensitive manner. 
       FIG. 5  is a schematic isometric view illustrating a variant example of the positive locking confirmation mechanism. The head portion of the terminal bole further comprises a circular groove, and an insulation safety clip  501  is accommodated within the circular groove. Consequently, even if the positioning bolt is loosened, the positioning bolt is still received within the positioning recess. 
     In another embodiment, an insulation packing (not shown) is arranged between the positioning bolt and the sensing contact. Due to the insulation packing, the voltage signal is not transmitted between the positioning bolt and the sensing contact. 
       FIG. 4  schematically illustrates a wiring configuration of the positive locking confirmation mechanism according to the embodiment of the present invention. For example, two battery management units are used to detect the voltage signals from individual electrodes and the locking states of individual electrodes. 
     For example, the locking state of a negative terminal  412  of a first battery pack  410  is sensed by a first sensing contact  461  of a first battery management unit  460 . The locking state of a positive terminal  411  of the first battery pack  410  is sensed by a second sensing contact  462  of the first battery management unit  460 . The locking state of a positive terminal  421  of a second battery pack  420  is sensed by a third sensing contact  463  of the first battery management unit  460 . The locking state of a positive terminal  431  of a third battery pack  430  is sensed by a fourth sensing contact  464  of the first battery management unit  460 . The locking state of a positive terminal  441  of a fourth battery pack  440  is sensed by a fifth sensing contact  465  of the first battery management unit  460 . Moreover, the locking state of the negative terminal  412  of the first battery pack  410  is also sensed by a first sensing contact  451  of a second battery management unit  450 . The locking state of a negative terminal  422  of the second battery pack  420  is sensed by a second sensing contact  452  of the second battery management unit  450 . The locking state of a negative terminal  432  of the third battery pack  430  is sensed by a third sensing contact  453  of the second battery management unit  450 . The locking state of a negative terminal  442  of the fourth battery pack  440  is sensed by a fourth sensing contact  454  of the second battery management unit  450 . The locking state of the positive terminal  441  of the fourth battery pack  440  is also sensed by a fifth sensing contact  451  of the second battery management unit  450 . 
     In  FIG. 4 , the locking states of the electrodes of four serially-connected battery packs are monitored by two battery management units.