Patent Document

The invention relates to electrically propelled motor vehicles comprising batteries designed to be accommodated in a compartment provided on the vehicle. 
     More particularly, the invention relates to the connection systems for connecting batteries to the electric motor of a motor vehicle. 
     Today, the batteries present in electric vehicles have a relatively short range. In order to respond to the need of consumers, the batteries have been modified so as to become removable in order to be rapidly exchanged when they are flat. The batteries are placed in a battery pack, then the battery pack is inserted into a dedicated compartment situated beneath the floor of the vehicle. The battery pack must therefore be easily accessible so that the batteries are rapidly replaced when they are discharged, so as to provide the vehicle user with a longer range. This replacement operation must be both rapid and perfectly protected. 
     Attempts have already been made in the prior art to achieve this objective. 
     In this respect reference can be made to document FR 2 798 342 which proposes a device allowing the easy and rapid interchangeability of a battery pack in an electric vehicle. A battery pack is inserted under the chassis of an electric vehicle, then immobilized in position by hooks. A smart card is situated on the battery pack and makes it possible to ascertain the cost of charging the battery pack. This document does not allow a protected electric connection to be obtained between the batteries and the electric motor of a vehicle. 
     Reference may also be made to document WO 02/04275 which describes the insertion of a battery into a compartment provided under the chassis of an electric vehicle and means for locking the battery in the compartment. When the battery is inserted into the compartment, its terminals are in contact with electric means of the vehicle thus making possible an energy interchange between the battery and the vehicle. The electric contact between the batteries and the vehicle is created when the battery is inserted into the compartment. No verification that the battery is immobilized in position and locked is carried out before the electric connection of the battery to the electric motor. 
     The solutions proposed in the prior art do not make it possible to carry out a perfectly protected battery-replacement operation. 
     BRIEF SUMMARY 
     The object of the invention is therefore to alleviate these drawbacks and to provide a battery-pack connection system that is rapid, automated and protected, in order to minimize the energy interchanges between the battery and the vehicle when the battery is not properly positioned and locked into a dedicated compartment in the vehicle, and to minimize the risks of short circuiting the batteries. 
     In one embodiment, the invention relates to a connection system for a battery pack designed to power at least one electric motor for propelling a motor vehicle and designed to be accommodated in a compartment provided on the vehicle. 
     Each battery comprises a logical processing unit, a communication module and connection means for connection to the motor. The vehicle comprises a logical processing unit connected to a fixed auxiliary battery, a communication module capable of communicating with the communication module of each battery and means for locking and immobilizing the batteries in position. The battery uses its own energy to provide the communication between the communication modules. In this manner, no energy interchange takes place between the batteries and the vehicle until the batteries receive an authorization signal from the communication module of the vehicle. 
     The connection system also comprises means for locking and closing the compartment and a first detection means associated with the vehicle. The first detection means is capable of detecting the state of the means for locking and closing the compartment. 
     Advantageously, the connection system comprises a second detection means associated with each of the batteries and/or with the vehicle. The second detection means is capable of detecting the state of the means for locking and immobilizing each battery in position. In this manner, the safety of the connection system is enhanced by a double check of the means for locking and immobilizing the batteries in position. 
     The connection means may comprise a mechanical actuating device capable of connecting the batteries to the electric motor of the vehicle. The mechanical device may be of the microactuator type. 
     The connection means may comprise an electric actuating device capable of connecting the batteries to the electric motor of the vehicle. The electric device may be of the relay type. 
     Advantageously, the communication modules of the batteries and of the vehicle may comprise optical data interchange means. 
     The communication modules of the batteries and of the vehicle may also comprise radiowave receiving and transmitting means. 
     According to the second aspect, the invention relates to a battery pack designed to power at least one electric motor for propelling a motor vehicle. Each battery comprises a logical processing unit, a communication module and connection means for connection to the vehicle. 
     Advantageously, each battery comprises a detection means for detecting its locking and its immobilization in position. 
     The connection means may comprise a mechanical actuating device or an electric actuating device capable of connecting the batteries to the electric motor of the vehicle. 
     The communication modules of the battery pack and of the vehicle may comprise optical data interchange means or radiowave receiving and transmitting means. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects, features and advantages of the invention will emerge on reading the following description, given only as a nonlimiting example, and made with reference to the appended drawings in which: 
         FIG. 1  represents very schematically a view in section of a vehicle chassis fitted with a battery pack according to the invention; 
         FIG. 2  represents a view in section along II-II of  FIG. 1 ; 
         FIG. 3  represents another embodiment of  FIG. 2 ; 
         FIG. 4  illustrates schematically the main elements of a system for connecting batteries to a vehicle according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
     The chassis  1  of a vehicle shown in  FIG. 1  comprises a compartment  2  fixed under the floor  3  of the vehicle. The compartment  2  is adapted to receive a pack  4  of batteries  5  in order to electrically connect them to the vehicle with the aid of connection means  6  fixed to the vehicle with the aid of means  7 . The connection means  6   a  correspond to the positive pole and the connection means  6   b  correspond to the negative pole. The batteries  5  may, as a nonlimiting example, be situated in two rows. However, it is possible to envisage inserting a number of rows of batteries  5  that is greater than two in the compartment  2 , depending on the energy requirement. 
     The battery pack  4  is enclosed in the compartment  2  with the aid of a means  8  for closing the compartment  2 . 
     Each battery  5  comprises terminals  9  and a communication means  10 . The terminals  9  are two in number. One of the terminals  9   a  corresponds to the positive pole and the other terminal  9   b  corresponds to the negative pole. The connection means  6   a  and  6   b  situated on the vehicle are two in number, so as to be in contact respectively with the positive pole of each of the batteries  5  and the negative pole of each of the batteries  5 . These connection means  6   a  and  6   b  are then linked to the power supply of the electric motor of the vehicle (not shown) in order to electrically propel the latter. 
     The communication means  10  comprises a communication module connected to a logical processing unit as will be seen when studying  FIG. 4 . The logical processing unit of the communication means  10  is called “movable” because it is fixed to one of the removable batteries  5 . The batteries  5  use their own energy to power their communication means  10 . 
     The chassis  1  of the vehicle also comprises a communication means  11  situated in a housing  12  between the compartment  2  and the bodywork  13  of said vehicle. The communication means  11  is fixed to a support  14  and comprises a communication module and a logical processing unit as will be seen when studying  FIG. 4 . The communication module of the vehicle is configured so as to communicate with each communication module situated on each battery  5 . The communication module of the communication means  11  is connected to the logical processing unit that is called “fixed” because it is situated on the vehicle. The vehicle comprises a fixed auxiliary battery  17  allowing the communication means  11  to operate without energy interchange with the batteries  5 . 
       FIG. 2  represents a view in section of the chassis  1  along II-II of  FIG. 1 . The batteries  5  are, as a nonlimiting example, six in number. Each of the batteries  5  comprises two terminals  9   a  and  9   b . The connection means  6   a  and  6   b  situated on the vehicle are contact bars, so as to be in contact respectively with the positive pole  6   a  of the batteries  5  and the negative pole  6   b  of the batteries  5 . These connection means  6   a  and  6   b  are then linked to the power supply of the electric motor of the vehicle (not shown) in order to allow the latter to be electrically propelled. 
     The communication means  10  and  11  may comprise radiowave receiving and transmitting means (not shown). 
     This embodiment requires the establishment of a protected and encrypted protocol so that external waves cannot interfere with the communication means  10  and  11 . 
     In the embodiment illustrated in  FIG. 3 , the communication means  10  and  11  may comprise, as an example, optical data interchange means (not shown). Each battery comprises a window  10  through which optical means (not shown) can interchange data with lia optical means situated on the vehicle so that the data interchange can take place only if the battery  5  is correctly placed in the compartment  2 . The data interchange is possible only if the compartment  2  comprises a window  15  and the battery pack  4  also comprises a window  16 . The windows  10 ,  16 ,  15  and the lia optical means are on the same axis, so as to allow the optical data stream to pass. The communication means  11  are two in number, so as to communication with the two rows of batteries  5 . 
     Communication between the batteries  5  and the vehicle via optical data interchange means provides double security of immobilizing the battery  5  in position because communication is not possible if the battery  5  is not correctly positioned. Moreover, the presence of light is easily detected with the aid of optical means. In this manner, it is easy to detect whether the compartment  2  is properly closed. 
     With reference now to  FIG. 4 , which illustrates as an example the main elements of a connection system for connecting a battery pack to a vehicle, the connection system  20  comprises a module  21  associated with each battery  5  and a module  22  associated with the vehicle. 
     The module  21  comprises an activation means  23 , a movable logical processing unit  24 , a communication module  25 , a detection means  26  for detecting whether the battery  5  is locked and immobilized in position, and an electric connection means  27  for connecting the battery  5  to the electric motor of the vehicle. The activation means  23  powers the movable logical processing unit  24  via a contactor  28  and a power supply  29  for the batteries  5  when the battery pack  4  is engaged in the compartment  2  illustrated in  FIG. 2 . 
     The module  22  comprises a fixed logical processing unit  30 , a communication module  31  and detection means  32  for detecting the locking and closing of the compartment  2  and the locking of the battery  5 . The communication module  25  is capable of communicating with the communication module  31 . 
     The battery can be locked, as a nonlimiting example, manually. However, the locking can be of the electromechanical type. The state of locking and of immobilization of the battery  5  in position is verified both by the vehicle and/or by the battery. The state of closure and of locking of the compartment  2  is verified only by the vehicle. It would be possible to envisage the state of closure and of locking of the compartment  2  to be verified also by each of the batteries  5 . 
     When the battery  5  is outside the vehicle, the connection means  27  is not activated. Thus the risks of handling and of short circuiting can be prevented. The movable logical processing unit  24  powered by the energy of the battery  5  is also inactive outside the vehicle so as to prevent unnecessary discharging of the battery. 
     When the battery pack  4  is inserted in the compartment  2 , the activation means  23  activates the movable logical processing unit  24  via the contactor  28 . The moveable logical processing unit  24  establishes communication between the communication module  25  of the battery  5  and the communication module  31  of the vehicle. The communication module  25  makes a request to the communication module  31  to ascertain whether the connection means  27  can be activated. The request is made in a continuous loop until the authorization to connect is obtained from the communication module  31 . Each of the communication modules  25  and  31  verifies that the corresponding battery  5  is correctly locked and immobilized in position in the compartment  2 . The detection means  26  and  32  for detecting the locking and immobilization of the battery  5  in position send signals reflecting the locked and positioned state of the battery  5  respectively to the communication modules and  31 . The detection means  32  also makes it possible to verify the locked and closed state of the compartment  2 . 
     When the communication module  31  receives the signal that the compartment  2  is locked and closed, it responds positively to the request sent by the communication module  25 . Once the positive response has been received by the communication module  25 , and once the communication module  25  has also received the signal reflecting the locked and immobilized state of the battery  5  in position via the means  26 , the communication module  25  activates the connection means  27 . The connection means  27  allows the connection C of the battery  5  to the electric motor of the vehicle. 
     The connection means  27  may be of several types. As a nonlimiting example, the batteries illustrated in  FIGS. 1 ,  2  and  3  are batteries  5  with exposed terminals  9 . In this embodiment, the terminals  9   a  and  9   b  of the batteries  5  are inert and do not interchange energy. The connection means  27  may, in this case, consist of a relay for powering up the terminals  9   a  and  9   b  and electrically connecting C the battery  5  to the electric motor of the vehicle. 
     However, it can be envisaged to use batteries with active masked terminals. In this embodiment, the connection means  27  may comprise a microactuator that is used to actuate the terminals of the battery so as to make them exposed. The latter embodiment has the advantage of protecting the terminals of the battery during handling. 
     By virtue of the invention that has just been described, the connection of the battery packs designed to power an electric motor for propelling a motor vehicle is protected, rapid and automated. 
     The invention allows the users of electric vehicles to change their batteries simply and rapidly so as to have as long a range as with a heat engine. Each of the batteries and the vehicle are considered to be standalone system communicating with one another so as to connect the batteries to the electric motor only when all the safety parameters have been verified by the vehicle and/or by each of the batteries. In this manner, the replacement of flat batteries with charged batteries is totally protected and can be carried out more rapidly.

Technology Category: 4