Patent Publication Number: US-2022216573-A1

Title: Connecting means between two parts of a bus bar

Description:
The invention relates to a connecting means for providing the junction between a first part of a bus bar and a second part of such a bus bar for electrical conduction between modules of a battery. The invention furthermore relates to a bus bar comprising such a connecting means. The invention furthermore relates to a battery comprising such a bus bar. The invention furthermore relates to an automobile vehicle comprising such a battery and/or such a bus bar. The invention furthermore relates to a method for assembling such a bus bar. 
     An automobile vehicle, in particular a hybrid or electric vehicle, generally comprises a battery comprising various modules. The volume of each module is generally maximum in view of the space available for accommodating it, generally on the floor, in order to maximize the energy storage capacities of each module. This thus results in a restricted space between the modules. However, two adjacent modules are generally connected together by a bus bar which provides the electrical conduction between these two modules. Thus, the lack of space between two modules renders the installation of the bus bar between them complex. 
     U.S. Pat. No. 8,802,259 B2 describes a particularly compact battery pack for an electric vehicle. It comprises vertically-stacked modules interconnected by flat bus bars. Each of the bus bars forms a complex structure since it is specially designed with respect to the arrangement of the modules in one area of the pack. Thus, these bus bars cannot be re-used if the arrangement of the modules is changed. In addition, they impose strict assembly constraints, because each bus bar needs to be able to be installed in a single operation, which is difficult in view of the complexity of each bus bar. 
     The aim of the invention is to provide a connecting means for a bus bar that overcomes the drawbacks hereinabove. In particular, the invention provides a connecting means that is simple, reliable and durable for installing a bus bar within a tight space between modules. 
     In order to achieve this aim, the invention relates to a connecting means designed to provide the electrical junction between a first part of an electrical conduction bus bar and a second part of said bus bar, the connecting means comprising:
         a male part designed to be rigidly attached to the first part of the bus bar, and   a female part designed to be rigidly attached to the second part of the bus bar, the male part and the female part being designed to fit into one another respectively following:   a first translational movement of the female part relative to the male part along a first axis, followed by;   a second rotational movement of the female part relative to the male part about a second axis perpendicular to the first axis, notably a rotation by a quarter of a turn or substantially by a quarter of a turn.       

     The male part may comprise a first electrical conduction element, notably in the form of a rectangular or substantially rectangular plate, where the female part may comprise a second electrical conduction element designed to come progressively into contact with the first conduction element throughout the first and second movements, notably a second electrical conduction element in the form of a yoke having two parallel or substantially parallel wings, designed to come progressively into contact with two opposing faces of the plate throughout the first and second movements. 
     Following the first and second movements, the two opposing faces of the plate may each have a contact area equal to at least four times a right cross-sectional area of a first part or of a second part of such a bus bar, and the two wings of the yoke may each have a contact area in contact with one of the two opposing faces of the plate, where the contact area may be equal to at least four times the right cross-sectional area of a first part or of a second part of such a bus bar. 
     The male part may comprise a first element for immobilizing the female part, notably a slot, and the female part may comprise a second immobilizing element designed to cooperate with the first immobilizing element, notably a second immobilizing element of the pin type, where the pin can become blocked within the slot following the first and second movements. 
     The male part may comprise an element for insertion of the second element for immobilizing the female part, notably a notch coming out at the slot. 
     The male part may comprise a means for end of travel in rotation, notably an end stop, coming into contact with the female part after the first and second movements. 
     The invention furthermore relates to an electrical conduction bus bar between modules of a battery, notably of a battery of a hybrid or electric automobile vehicle, the bus bar comprising:
         a first part, and   a second part, and   a connecting means between the first and the second parts such as previously defined.       

     The invention furthermore relates to a battery, notably for a hybrid or electric automobile vehicle, the battery comprising at least one bus bar such as previously defined. 
     The invention furthermore relates to a hybrid or electric automobile vehicle, comprising a battery such as previously defined and/or at least one bus bar such as previously defined. 
     The invention furthermore relates to a method for assembling a bus bar such as previously defined, notably for electrically connecting two modules of a battery together, the method comprising a step for supplying:
         a first part of a bus bar comprising a male part,   a second part of a bus bar comprising a female part, followed by a step for engaging the male part in the female part by following a first translational movement of the female part relative to the male part in a main plane containing the main longitudinal axis of the bus bar in the final connected position, followed by a step for blocking the female part with the male part by following a second rotational movement of the female part with respect to the male part about or substantially about a second axis perpendicular to the main plane, notably a rotation of a quarter of a turn or substantially of a quarter of a turn.       

     The engagement step may comprise an insertion phase during which a second element for immobilizing the female part, notably a pin, is inserted into an insertion element of the male part, notably a notch. 
     The blocking step may comprise an end of travel in rotation of the female part against an end of travel means arranged on the male part, notably an end stop, such that a second element for immobilizing the female part is pushed back into a first element for immobilizing the male part, notably a slot. 
    
    
     
       These subjects, features and advantages of the present invention will be presented in detail in the following description of one embodiment of an automobile vehicle, by way of non-limiting example, in relation with the appended figures amongst which: 
         FIG. 1  is a schematic view of an automobile vehicle according to one embodiment of the invention. 
         FIG. 2  is a perspective view of a battery of the automobile vehicle according to one embodiment of the invention. 
         FIG. 3  is a detailed perspective view of the battery according to the embodiment of the invention. 
         FIG. 4  is a partial perspective view of the battery according to the embodiment of the invention. 
         FIG. 5  is a perspective view of a female part of a connecting means for a bus bar according to one embodiment of the invention. 
         FIG. 6  is another perspective view of the female part of the connecting means according to the embodiment of the invention. 
         FIG. 7  is a detailed perspective view during the method of assembly of the bus bar between two modules of the battery according to the embodiment of the invention. 
         FIG. 8  is another detailed perspective view during the method for assembling the bus bar between two modules of the battery according to the embodiment of the invention. 
         FIG. 9  is another detailed perspective view during the method for assembling the bus bar between two modules of the battery according to the embodiment of the invention. 
         FIG. 10  is another detailed perspective view during the method for assembling the bus bar between two modules of the battery according to the embodiment of the invention, the female part being shown in transparency mode. 
         FIG. 11  is another detailed perspective view during the method for assembling the bus bar between two modules of the battery according to the embodiment of the invention, the second part being shown in transparency mode. 
         FIG. 12  is a perspective view of the bus bar in the final connected position according to the embodiment of the invention. 
         FIG. 13  is another detailed perspective view of the bus bar in the final connected position according to the embodiment of the invention, the second part being shown in transparency mode. 
     
    
    
     The direction in which an automobile vehicle is traveling in a straight line is defined as being the longitudinal direction X. By convention, the direction perpendicular to the longitudinal direction, situated in a plane parallel to the ground, is called transverse direction Y. The third direction, perpendicular to the other two, is called vertical direction Z. Thus, a right orthogonal reference frame XYZ is used in which X is the longitudinal direction in the front-rear direction of the vehicle, hence directed toward the rear, Y is the transverse direction directed toward the right and Z is the vertical direction directed upward. 
     The “forward” direction corresponds to the direction in which the automobile vehicle is usually traveling in the longitudinal direction and is opposite to the “back” direction. 
     One example of an automobile vehicle  1  according to one embodiment of the invention is illustrated schematically in  FIG. 1 . The automobile vehicle  1  is for example an electric vehicle or a hybrid vehicle, known by the abbreviation HEV for “Hybrid Electric Vehicle”, or else a rechargeable plug-in hybrid vehicle known by the abbreviation PHEV for “Plug-in Hybrid Electric Vehicle”. The automobile vehicle  1  preferably comprises a body or housing  2 . The automobile vehicle  1  comprises a battery  10 , for example fixed onto the housing  2 . The battery  10  comprises at least two modules. 
     For example, as illustrated in  FIG. 2 , the battery  10  comprises front modules  11  and rear modules  12 . For example, the battery  10  comprises eight front modules and two rear modules  12 . For example, the rear modules  12  are separated from the front modules  11  by means of a separation or partition  3 . 
     As illustrated in  FIG. 3 , the battery  10  furthermore comprises a bus bar  13  or current-conducting bar or power bar or distribution bar. Here, this bar  13  is designed to electrically connect a front module  11  and a rear module  12 . The electrical conduction bus bar  13  between modules comprises a first part  20  and a second part  50 . 
     Preferably, the first part  20  comprises a part  21  designed for the electrical connection and/or for the fixing of the first part  20  onto the front module  11 . Preferably, the second part  50  comprises a part  51  designed for the electrical connection and/or for the fixing of the second part  50  onto the rear module  12 . 
     Preferably, the second part  50  of the bus bar  13  principally extends in a main plane P, or substantially in a main plane P, notably in the final assembled position of the bar  13 . For example, the part  51  extends perpendicularly to the second part  50 . For example, the main plane P extends vertically, or substantially vertically, and transversally, or substantially transversally, as illustrated in  FIGS. 3 and 4 . 
     The bar  13  furthermore comprises a connecting means  40  or fixing or assembly means allowing the first part  20  to be connected and/or fixed to the second part  50 . Furthermore, the connecting means  40  allows the electrical conduction of the first part  20  to the second part  50  and potentially vice versa. 
     Thus, the connecting means  40  provides the junction between the first part  20  of the bus bar  13  and the second part  50  of the bus bar  13 . More precisely, the connecting means  40  comprises a male part  30  rigidly attached to the first part  20  and a female part  60  rigidly attached to the second part  50 . 
     The phrase “rigidly attached” is understood to mean that the male part  30  is fixed to the first part  20 , or even, preferably, that the male part  30  extends from the first part  20 . Advantageously, the male part  30  and the first part  20  only constitute a single component. Thus, it is understood that the female part  60  is fixed o the second part  50 , or even, preferably, that the female part  60  extends from the second part  50 . Advantageously, the female part  60  and the second part  50  only constitute a single component. 
     The male part  30  and the female part  60  cooperate with one another so as to provide both the fixing of the male part with the female part and the electrical conduction between the male part and the female part and vice versa. 
     Preferably, the first part  20 , in particular the male part  30  of the first part  20 , also extends in the main plane P, or substantially in the main plane P, notably prior to the insertion of the female part  60  which is explained in the following part. 
     The fixing of the male part with the female part is carried out in two stages. As illustrated in  FIGS. 8 , and  10  with a straight and thick arrow, the first stage comprises a translational movement. This relative translation of the female part  60  with respect to the male part  30 , preferably downward, is implemented along a first axis A 1 , for example vertical or substantially vertical. The first axis A 1  is parallel to the main plane P, or even included, or substantially included, within the main plane P. To continue this fixing and to provide an optimum grip, as illustrated in  FIGS. 10 and 11 , the second stage comprises a rotation of the female part  60  with respect to the male part  30  about a second axis A 2  perpendicular to the first axis A 1 . The second axis A 2  is perpendicular, or substantially perpendicular, to the main plane P. Preferably, the second movement, this time a rotation, is implemented over an angle of around 90 degrees, in other words over a quarter of a turn or substantially a quarter of a turn. As previously mentioned and illustrated in particular in  FIGS. 11, 12 and 13 , a main longitudinal axis AP of the bus bar  13  in the final connected position is included, or substantially included, within the main plane P. 
     The electrical conduction between the first part  20  and the second part  50  is provided by the male part and the female part. For this purpose, the male part  30  comprises a first electrical conduction element  31  and the female part  60  comprises a second electrical conduction element  61 . The first electrical conduction element  31  cooperates with the second electrical conduction element  61  so as to conduct the electrical current from the male part to the female part and potentially vice versa. Indeed, the second electrical conduction element  61  is designed to be in contact with the first conduction element  31 , in particular once the bar  13  is in its final connected position, in other words after the rotation about the second axis A 2 , as illustrated in particular in  FIGS. 12 and 13 . 
     Advantageously, as illustrated in  FIG. 7  with hatching, the first electrical conduction element takes the form of a plate  32 , preferably parallelepipedal. Preferably, the two largest opposing faces  33 ,  34  of the plate  32  each have a contact surface area S 30 . This contact area S 30  is preferably equal to at least four times a right cross-sectional area of the first part  20 . This right cross-sectional area is obtained following a plane PS 20  perpendicular to the dimension in which the part  21  mainly extends, as illustrated in figure V. 
     Advantageously, as illustrated in  FIGS. 5 and 6 , the second electrical conduction element  61  takes the form of a yoke  62  having two parallel or substantially parallel wings  63 ,  64 . Thus, the internal areas of the wings  63 ,  64  come into contact with the two opposing faces  33 ,  34  of the plate  32  as soon as the female part is inserted over the male part. In other words, the two wings of the yoke pinch the plate. Thus, in the final connected position of the bar  13 , the two wings  63 ,  64  of the yoke  62  each have a contact surface area S 60  in contact with a contact area S 30  of each opposing face  33 ,  34  of the plate  32 . The contact area S 60  is preferably equal to at least four times the right cross-sectional area of the second part  50 . This right cross-sectional area is obtained following a plane PS 50  perpendicular to the dimension in which the second part  50  mainly extends, as illustrated in  FIG. 6 . 
     In the final connected position of the second part  50  with the first part  20 , the wings  63 ,  64  of the yoke  62  extend, or substantially extend, parallel to the main plane P, the contact areas S 30 , S 60  being in contact. 
     Preferably, the right cross-sectional area of the first part  20  is equal, or substantially equal, to the right cross-sectional area of the second part  50 . More preferably, the shape of the right cross-section of the first part is identical, or substantially identical, to the shape of the right cross-section of the second part. For example, the first and second parts  20 ,  50  have rectangular right cross-sections. Indeed, the first and second parts  20 ,  50  are preferably “metal flats”, in other words flat metal strips whose thickness is much less than its width and its length. 
     As illustrated in particular in  FIGS. 10 and 13 , the male part  30  of the connecting means  40  comprises a first immobilizing element  36  for the female part  60 . This first immobilizing element is preferably a slot or a groove. The female part  60  then comprises a second immobilizing element  66  designed to cooperate with the first immobilizing element  36 . This second immobilizing element is preferably a pin designed to block itself within the slot. Indeed, the diameter of the pin  66  is for example less than, or only just less than, the diameter of the orifice generated by the slot  36 . Advantageously, as illustrated in  FIGS. 10 and 13 , the male part  30  furthermore comprises an element  37  for insertion of the pin  66  of the female part  60 . Preferably, this insertion element is a notch coming out at the slot or in the slot. More preferably, the male part  30  comprises a means for end of travel in rotation  38 , for example an end stop, arranged on the side of the face  33  of the plate  32 . As illustrated in  FIG. 13 , this end stop  38  then comes into contact with the female part  60  when the second part  50  extends along the main longitudinal axis AP of the bus bar  13  in its final connected position. For example, the contact between the end stop  38  of the male part  30  and the female part  60  is made at the edge  65  of the wing  63  of the yoke  62 . 
     Alternatively or as a complement, an end stop may be arranged on the side of the face  34  of the plate  32  so as to come into contact with an edge of the wing  64  of the yoke  62 . Alternatively, a single end stop is arranged on the side of the face  34  of the plate  32  so as to come into contact with an edge of the wing  64  of the yoke  62 . 
     Prior to the method for assembling the bus bar  13  which will be described in the following part, the front  11  and rear  12  modules are installed in or on the body  2  or the housing designed to receive them. 
     One embodiment of a method for assembling the bus bar  13  in such a manner that it extends between two battery modules is described hereinafter. 
     The method firstly comprises a step for supplying the first part  20  of the bus bar  13 , the first part  20  comprising the male part  30 , and for supplying the second part  50  of the bus bar  13 , the second part  50  comprising the female part  60 . 
     It should be noted that, for the sake of clarity,  FIGS. 7, 8, 10, 11, 12 and 13  do not show any rear module  12 . However, it is important to underline that the bus bar  13  is designed so as to be compatible with an installation while the front module or modules  11  and the rear module or modules  12  are already installed. Similarly, the method for assembling the bus bar, in particular between a front module  11  and a rear module  12 , is compatible with the front module or modules  11  and the rear module or modules  12  being already installed. Indeed, as a reminder, one of the aims of the invention is to facilitate the installation of the electrical connection via a bus bar within a restricted space between two modules for example. 
     In the case of the presence of a partition  3  between a front module  11  and a rear module  12  that it is desired to connect together via the bar  13 , preferably a hole  4  or orifice is arranged in the partition  3 . In this case, the male part  30  of the first part  20  is engaged within the hole  4  such that it passes through it and that the male part is located on the side of the rear module  12 , as illustrated by an arrow in  FIG. 7 . Subsequently, the first part  20  is fixed, for example by screwing with a screw passing through the part  21  and which cooperates with the front module  11 . 
     As illustrated in  FIG. 8 , a step is subsequently carried out for engaging the female part  60  in the male part  30  by a first translational movement of the female part  60  relative to the male part  30  in the main plane P, or substantially in the main plane P. More precisely, the first translational movement is applied along the first axis A 1 , for example in the vertical direction or substantially in the vertical direction, downward. Thus, the second part  50  is approached from the top of the battery  10 . In other words, the wings  63 ,  64  of the yoke  62  are engaged on either side of the plate  32 . The contact areas S 30  of the plate  32  and the contact areas S 60  of the yoke  62  are then in contact with one another. It should be noted that the limited thickness along the second axis A 2  of the yoke  62  allows it to pass between the rear module  12  and the body  2 , or between the rear module  12  and the partition  3 . 
     As illustrated in  FIG. 10 , the engagement step preferably comprises an insertion phase, or end of translation, during which the pin  66  of the female part is inserted, or accommodated, or guided into the notch or groove  37  of the male part  30 . From this point, two degrees of freedom between the female part and the male part are blocked. 
     As illustrated in  FIG. 11 , a final step for blocking or installing or fixing of the female part  60  with the male part  30  is subsequently carried out. Preferably, this blocking step is implemented by rotation of the female part  60  with respect to the male part  30  about, or substantially about, the second axis A 2 . This second rotational movement is carried out in the sense S illustrated by a curved arrow in  FIGS. 10 and 11 . As previously mentioned, the second axis A 2  is perpendicular to the main plane P containing the main longitudinal axis AP of the bus bar  13  in the final connected position. In the embodiment illustrated, the blocking step ends after a rotation of a quarter of a turn, or substantially of a quarter of a turn. The contact areas S 30  of the plate  32  and the contact areas S 60  of the yoke  62  are then completely, or substantially completely, in contact with one another. 
     Advantageously, the blocking step comprises an end of travel in rotation of the female part  60 . For example, this end of travel is implemented by the contact of the female part  60 , for example one edge  65  of the wing  63  of the yoke  62 , against the end stop  38  arranged on the male part  30  on the side of the face  33  of the plate  32 . The end stop  38  thus blocks a third degree of freedom, the translation following the main longitudinal axis AP. 
     Preferably, in particular in order to avoid any interaction between the end stop  38  and the yoke  62  hindering or preventing the translation of the female part  60  within the notch  37  and/or the rotation of the blocking step, a chamfer  67  is provided. This chamfer is formed on at least one, or even both wings  63 ,  64 , of the yoke as illustrated in particular in  FIGS. 6 and 10 . More preferably, as illustrated in  FIGS. 5 and 6 , a protrusion or notch  68  is provided in the part holding the two wings of the yoke in order to avoid an interaction with the contour of the notch  37  during the translation and/or of the rotation. 
     It should be noted that, by reason of its contact against the edge  65  of the wing  63  of the yoke  62 , the end stop  38  forces the pin  66  into the slot  36 , in particular to the bottom of this slot, and thus participates in an optimum positioning of the female part with respect to the male part. 
     Finally, in order to provide the electrical conduction sought between the front module  11  and the rear module  12 , the second part  50  is fixed onto the rear module  12 , for example by screwing of a screw through the part and which then cooperates with the rear module. 
     Accordingly, all the degrees of freedom of the male part  30  with respect to the female part  60 , and as a consequence of the first part  20  with respect to the second part  50 , are totally blocked, as illustrated in the final connected position of the bar  13  in  FIG. 12 . 
     This results in the bus bar  13  principally extending in the main plane P, parallel or substantially parallel to faces extending vertically and transversally of the modules  11 ,  12  and/or of the partition  3 . The thickness of the female part along the second axis A 2 , for example in the range between 2 mm and 5 mm, preferably of the order of 3 mm, allows the rear module  12  to be arranged as near as possible to the partition  3  for example. 
     Such a bus bar only occupies a limited space and allows the volume of the modules, in other words the storage capacity for electrical energy within the battery  10 , to be maximized. 
     Although the bar has been described so as to electrically connect a front module  11  with a rear module  12 , the bus bar equipped with the connecting means  40  may also allow for example two front modules to be connected together or two rear modules to be connected together. 
     In summary, the “intermodule” connection is provided by the bus bar  13  despite its particular shape and its length, in particular owing to the positioning of its connection points on the modules. It may be assembled after installing the modules. This installation or assembly can be achieved despite the restricted space for its insertion, in particular between the rear module  12  and the body  2 . 
     Furthermore, the contact areas S 30 , S 60  on the connecting means  40  comply with the rule stating that the electrical conduction area is equal to at least four times the cross-sectional area of the bus bar in order to provide a good electrical conduction. 
     Indeed, the internal areas S 60  of the wings  63 ,  64  of the yoke  62  in contact with the areas S 30  of the opposing surfaces  33 ,  34  comply with this condition. In addition, both the first part  20  and the adjacent male part  30 , together with both the second part  50  and the adjacent female part  60 , have an appropriate cross-sectional area. It should be noted that the two wings  63 ,  64  of the yoke  62  provide plane or substantially plane contacts against the opposing faces  33 ,  34  of the plate  32  so as to provide an optimal electrical conduction. Preferably, the yoke  62  comprises an elastic part between its two wings so as to maintain firm contacts between the wings  63 ,  64  and the opposing faces  33 ,  34  of the plate  32 . Furthermore, in order not to alter this elasticity, the pin  66  is preferably only fixed onto one wing of the yoke  62  so as not to affect the rigidity of the yoke and not to affect the separation of its two wings. For example, the separation between the two wings  63 ,  64  is slightly less than the separation between the two opposing faces  33 ,  34  so as to generate an elastic force providing a grip of the yoke  62  on the plate  32 . 
     Thus, this bus bar in two parts which are fixed together offers an enhanced flexibility during the assembly, where the modules  11 ,  12  are able to be installed prior to the installation of the bar  13 . The connecting means  40  is particularly compact which offers a gain of space and consequently the possibility of increasing the volume for electrical energy storage of the battery  10 . 
     The connection or assembly or fixing of the female part with the male part is quick, simple and reliable. 
     It is noted that the solution therefore achieves the aim sought of facilitating the electrical connection between two modules of a battery, in particular separated by a partition, and offers the following advantages:
         The connecting means  40  is simple to produce and makes use of widely available manufacturing techniques (cutting out, bending/folding, drilling), which renders it particularly economical;   The yoke  62  may be obtained by bending/folding;   The junction between the first part and the second part is formed without any specific tool;   The first and second parts  20 ,  50  of the bus bar may be dismantled, separated and reused, notably rendering the removal of a module straightforward, for example in order to change it or allow its maintenance or its exchange outside of its location;   The notch  37 , the pin  66  and the slot  36  at the same time provide a function of guide pin which avoids any erroneous installation.