Abstract:
A battery assembly according to an exemplary aspect of the present disclosure includes, among other things, an enclosure assembly defining an interior and a service panel integrally formed in the enclosure assembly. The service panel includes a ductile portion that is removable to access the interior.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 14/030,335, which was filed on Sep. 18, 2013. 
     
    
     TECHNICAL FIELD 
       [0002]    This disclosure relates to a service panel, and more particularly, but not exclusively, to a thermoplastic service panel that is removable to expose a serviceable part. 
       BACKGROUND 
       [0003]    Hybrid electric vehicles (HEV&#39;s), plug-in hybrid electric vehicles (PHEV&#39;s), battery electric vehicles (BEV&#39;s) and other known electrified vehicles differ from conventional motor vehicles in that they employ one or more electric machines in addition or in alternative to an internal combustion engine to drive the vehicle. Electrified vehicles may also be equipped with a battery that stores electrical power for powering the electric machines. In some vehicles, an electric machine may also be employed as a generator that is powered by the internal combustion engine in order to generate electrical power to charge the battery. 
         [0004]    Some electric vehicle components, including but not limited to the battery, may be mounted external to the vehicle&#39;s body structure. Accordingly, these components must be designed to permit access to serviceable parts located therein while adequately resisting moisture ingress. 
       SUMMARY 
       [0005]    A battery assembly according to an exemplary aspect of the present disclosure includes, among other things, an enclosure assembly defining an interior and a service panel integrally formed in the enclosure assembly. The service panel includes a ductile portion that is removable to access the interior. 
         [0006]    In a further non-limiting embodiment of the foregoing battery assembly, the interior accommodates at least one serviceable part. 
         [0007]    In a further non-limiting embodiment of either of the foregoing battery assemblies, the enclosure assembly includes a tray made of a first material and a cover made of a second material different from the first material. 
         [0008]    In a further non-limiting embodiment of any of the foregoing battery assemblies, the first material is a metal and the second material is a thermoplastic. 
         [0009]    In a further non-limiting embodiment of any of the foregoing battery assemblies, the ductile portion includes a tear strip. 
         [0010]    In a further non-limiting embodiment of any of the foregoing battery assemblies, a pull tab is connected to the tear strip. 
         [0011]    In a further non-limiting embodiment of any of the foregoing battery assemblies, the tear strip is defined by a first groove and a second groove that are molded into a portion of the enclosure assembly. 
         [0012]    In a further non-limiting embodiment of any of the foregoing battery assemblies, the service panel includes a center body that is bounded by the tear strip. 
         [0013]    In a further non-limiting embodiment of any of the foregoing battery assemblies, the ductile portion includes a perforation. 
         [0014]    In a further non-limiting embodiment of any of the foregoing battery assemblies, the perforation circumscribes an outer periphery of a membrane of the service panel. 
         [0015]    In a further non-limiting embodiment of any of the foregoing battery assemblies, a replacement panel is configured to reseal the interior after removal of at least the ductile portion. 
         [0016]    In a further non-limiting embodiment of any of the foregoing battery assemblies, the ductile portion is irreversibly removable from the enclosure assembly. 
         [0017]    An electrified vehicle battery according to another exemplary aspect of the present disclosure includes, among other things, a tray comprised of a first material, a cover attached to the tray and comprised of a second material different from the first material and a service panel integrally formed as part of the cover. A portion of the service panel is plastically deformable to expose an interior of the electrified vehicle battery. 
         [0018]    In a further non-limiting embodiment of the foregoing battery assembly, the first material is metallic and the second material is plastic. 
         [0019]    In a further non-limiting embodiment of either of the foregoing battery assemblies, the portion of the service panel includes a tear strip and a center body bounded by the tear strip. 
         [0020]    In a further non-limiting embodiment of any of the foregoing battery assemblies, the tear strip is established by a first groove and a second groove formed in the cover. 
         [0021]    In a further non-limiting embodiment of any of the foregoing battery assemblies, a pull tab is connected to the tear strip. 
         [0022]    In a further non-limiting embodiment of any of the foregoing battery assemblies, one of the first groove and the second groove terminates short of the pull tab such that the center body remains attached to the tear strip after plastically deforming the portion of the service panel. 
         [0023]    In a further non-limiting embodiment of any of the foregoing battery assemblies, the cover includes a first portion comprised of the second material and a second portion comprised of a third material. 
         [0024]    In a further non-limiting embodiment of any of the foregoing battery assemblies, the second material is a thermoplastic and the third material is a metal. 
         [0025]    The various features and advantages of this disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  schematically illustrates a powertrain of an electrified vehicle. 
           [0027]      FIG. 2  illustrates a battery assembly of an electric vehicle. 
           [0028]      FIG. 3  illustrates a first embodiment of a service panel of a battery assembly. 
           [0029]      FIGS. 4A, 4B and 4C  illustrate a replacement panel of a battery assembly. 
           [0030]      FIG. 5  schematically illustrates a method for providing access to one or more serviceable parts of a battery assembly. 
           [0031]      FIG. 6  illustrates a second embodiment of a service panel. 
           [0032]      FIG. 7  illustrates an enclosure assembly having a service panel for accessing at least one serviceable part housed within the enclosure assembly. 
           [0033]      FIG. 8  illustrates a portion of a service panel of a battery assembly. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    This disclosure relates to a service opening and panel for a battery assembly or other enclosure assembly. The service panels of this disclosure are integrated into an enclosure assembly and include a ductile portion that may be removed to expose one or more serviceable parts located inside the enclosure assembly. Among other features, the enclosure assemblies described herein do not require relatively expensive and complex sealing gaskets, fasteners and other parts to be provided as part of the enclosure cover. 
         [0035]      FIG. 1  schematically illustrates a powertrain  10  for an electrified vehicle  12 . The electrified vehicle  12  may be a HEV, PHEV or BEV, or any other vehicle. In one embodiment, the powertrain  10  includes a drive system having at least a motor  36  and a battery assembly  50 . The drive system generates torque to drive one or more sets of vehicle drive wheels  30  of the electrified vehicle  12 . For example, the motor  36  can be employed to drive the vehicle drive wheels  30  by outputting torque to a shaft  46 . The battery assembly  50  may be a high voltage battery that is capable of outputting electrical power to operate the motor  36 . Of course, this view is highly schematic and it should be appreciated that other devices, such as an internal combustion engine, a generator and/or a power transfer unit, could be incorporated for use with the electrified vehicle  12 . 
         [0036]      FIG. 2  illustrates a battery assembly  50  that can be incorporated into an electrified vehicle, such as the electrified vehicle  12  of  FIG. 1 . Among other hardware, the battery assembly  50  may include an enclosure that can house one or more battery cells (not shown) for supplying electrical power to the motor  36  of the electric vehicle  12  (see  FIG. 1 ). 
         [0037]    In one embodiment, the battery assembly  50  includes a tray  62  and a cover  64  attached to the tray  62 . The tray  62  and cover  64  establish an enclosure assembly that defines an interior  66  for housing various hardware and electronics of the battery assembly  50 . In one embodiment, the cover  64  is attached to the tray  62  in a manner that hermetically seals the interior  66 . The cover  64  may be attached to the tray  62  in any known manner For example, the cover  64  could be bolted to the tray  62 . Other mechanical attachment mechanisms are also contemplated. 
         [0038]    The cover  64  may include sidewalls  68  that extend from a top panel  70  of the cover  64  toward the tray  62 . Alternatively, the sidewalls  68  could extend from the tray  62 . This disclosure is not limited to the specific battery assembly  50  shown in  FIG. 2 , and it should be appreciated that the tray  62  and the cover  64  may embody any size, shape or configuration. 
         [0039]    In one embodiment, the tray  62  is made of a first material and the cover  64  is made of a second material that is different from the first material. For example, the tray  62  may be made of metal, while the cover  64  is made from a thermoplastic. Exemplary thermoplastics include, but are not limited to, polypropylene (PP) and high density polyethylene (HDPE). In another embodiment, the cover  64  has portions made from metal and other portions made from thermoplastics. In other words, the cover  64  can be a hybrid structure composed of multiple materials. 
         [0040]    The battery assembly  50  may additionally include a service panel  72  (shown outlined in dashed lines in  FIG. 2 ). The service panel  72  may embody a variety of sizes and shapes, and may span the entirety of, or across only a portion of, the top panel  70  of the cover  64 . In the illustrated embodiment, the service panel  72  is smaller than the top panel  70  of the cover  64 . 
         [0041]    In one embodiment, the service panel  72  is integrally formed as part of the top panel  70  of the cover  64 . At least a portion of the service panel  72  is removable to provide access to the interior  66  of the battery assembly  50 . The entirety or a portion of the service panel  72  may be removed to expose one or more serviceable parts  74  housed within the battery assembly  50 . 
         [0042]    The service panel  72  may include a ductile portion  76  that is removable to access the interior  66  of the battery assembly  50 . In this disclosure, the term “ductile portion” is intended to denote a section of the service panel  72  that, once plastically deformed, cannot be reattached to the battery assembly  50  without requiring modifications or the use of additional attachment mechanisms. In one embodiment, the ductile portion  76  is an irreversibly removable portion of the service panel  72 . 
         [0043]      FIG. 3  illustrates an exemplary service panel  72  that can be incorporated into a battery assembly  50 . The service panel  72  is not necessarily shown to the scale it would be in practice and some features may be enlarged to better illustrate their design and operability. 
         [0044]    In the illustrated embodiment, the service panel  72  has a ductile portion  76  that includes a tear strip  78  and a center body  84  bounded by the tear strip  78 . The tear strip  78  may be defined by a first groove  80  and a second groove  82  that are molded into the service panel  72  or the cover  64  of the battery assembly  50 . As discussed in greater detail below, the ductile portion  76  can be plastically deformed, such as by pulling the tear strip  78  to expose the serviceable parts  74  (shown in phantom) housed inside the battery assembly  50 . 
         [0045]    The first groove  80  and the second grooves  82  may extend in parallel along a surface of the top panel  70  of the cover  64  (shown in cross-section in  FIG. 8 ). Although shown embodying a rectangular shape, the grooves  80 ,  82  could take the form of other shapes such as circular, square or irregular shapes. The grooves  80 ,  82  are spaced apart by a distance d. In one embodiment, the distance d is approximately 6 to 10 millimeters (0.24-0.39 inches). However, the first groove  80  and the second groove  82  may be spaced apart any distance. The tear strip  78  is the piece of material that extends across the distance d between the first groove  80  and the second groove  82  to connect the center body  84  to the top panel  70  of the cover  64 . 
         [0046]    The tear strip  78  may include a pull tab  86  connected to the tear strip  78 . In an exemplary embodiment, the pull tab  86  is pulled to exceed the strain capability of the ductile portion  76  of the service panel  72  and begin severing the tear strip  78  from the cover  64 . The tear strip  78  is pulled between the two grooves  80 ,  82  to release the center body  84  from its attachment to the cover  64 . The tear strip  78  is pulled completely around a perimeter  79  of the center body  84  until it arrives back to its origin (i.e., the original location of the pull tab  86 ). The center body  84  may then be removed to expose the serviceable part(s)  74 . In one embodiment, the inner groove  82  may not be a complete loop, ending just short of the pull tab  86 , such that the center body  84  remains connected to the tear strip  78  and both the tear strip  78  and the center body  84  can be removed as one piece. 
         [0047]      FIGS. 4A, 4B and 4C , with continued reference to  FIGS. 2-3 , illustrate a replacement panel  88  that can be used to seal an opening  99  (see  FIGS. 4C and 5 ) formed in the cover  64  of the battery assembly  50  as a result of plastically deforming the ductile portion  76  of the service panel  72  to expose one or more serviceable part(s). The battery assembly  50  is shown prior to removal of the ductile portion  76  in  FIG. 4A . The replacement panel  88  may be positioned over the opening  99  in the cover  64  after removal of at least a portion of the service panel  72  and after the serviceable parts have been serviced (see, for example,  FIG. 4C ). 
         [0048]    The replacement panel  88  includes a cover body  90  and, optionally, at least one seal  92  (see  FIGS. 4B and 4C ) that can be received between the replacement panel  88  and the cover  64  of the battery assembly  50 . In one embodiment, the seal  92  is a gasket seal that is compressed between the replacement panel  88  and the cover  64 . However, other seals are also contemplated. The seal  92  may be received within a molded-in recess  91  of the replacement panel  88  (see  FIGS. 4B and 4C ). 
         [0049]    The cover body  90  may include a plurality of cavities  93  that receive fasteners  95  for fixedly attaching the replacement panel  88  to the cover  64 . Matching cavities  97  are formed in the cover  64  for receiving the fasteners  95 . In one embodiment, the cavities  97  of the cover  64  are molded into the cover  64  and include closed bottoms  89  that allow the replacement panel  88  to be retained without producing a leakage point at the joint between the replacement panel  88  and the cover  64 . The cover  64  can additionally include a strengthening rib  87  (see  FIG. 4C ) to provide structure to the service panel  72  after the ductile portion  76  has been removed. Of course, many alternative designs and configurations of ribs, gussets, wall thicknesses and other features of the replacement panel  88  are contemplated as within the scope of this disclosure. 
         [0050]    In one embodiment, the replacement panel  88  is a stand-alone component that is separate and distinct from the service panel  72 . In another embodiment, the replacement panel  88  is constructed by recycling the tear strip  78  and/or the center body  84  of the service panel  72 . For example, a seal and a retention feature may be added to the center body  84  to construct the replacement panel  88 . 
         [0051]      FIG. 5 , with continued reference to  FIGS. 2, 3 and 4 , schematically illustrates a method  100  for accessing the interior  66  of the battery assembly  50 . The method begins at step  102  by determining whether a serviceable part  74  of the battery assembly  50  requires servicing. The serviceable part  74  could include one or more of the following parts: a control module, electronics, a BUS electrical center, a fuse, a battery cell, or any other component of the battery assembly  50 . Step  102  can be performed manually or electronically by monitoring the health of the battery assembly  50 , including the health of its internal components. 
         [0052]    The method  100  ends in the event servicing is not required. However, the method proceeds to step  104  if a determination is made that one or more serviceable parts  74  require service. Step  104  includes plastically deforming a ductile portion  76  of a service panel  72  of the battery assembly  50 . In one embodiment, plastic deformation is achieved by applying a force, in any direction, to the pull tab  86  that is connected to the tear strip  78 . The pull tab  86  may be pre-formed as part of the tear strip  78  or could be formed by a cutting operation that frees an end of the tear strip  78 . The pull tab  86  may be moved manually or with a tool to sever the tear strip  78  from the grooves  80 ,  82 . 
         [0053]    In one embodiment, a pulling force F is applied to the pull tab  86  (in either direction) until the strain capability of the ductile portion  76  is exceeded. This pulling force F severs the tear strip  78  from the cover  64 . The tear strip  78  is pulled around a perimeter  79  of the center body  84  (see  FIG. 3 ) until reaching the original location of the pull tab  86  to completely sever the tear strip  78  from the cover  64 . 
         [0054]    At step  106 , the serviceable part(s)  74  are exposed. In other words, the interior  66  of the battery assembly  50  is accessible in response to plastically deforming the ductile portion  76  during step  104 . 
         [0055]    Next, at step  108 , the exposed serviceable part(s)  74  may be serviced. Any service, including maintenance tasks or part replacement, may be performed during this step. 
         [0056]    Finally, at step  110 , the battery assembly  50  may be resealed by a replacement panel  88 . In one embodiment, the replacement panel  88  is a new part that replaces the service panel  72  or the portions of the service panel  72  previously removed during step  104 . In another embodiment, portions of the service panel  72  can be recycled to construct the replacement panel  88 . The replacement panel  88  is positioned to cover an opening  99  formed in the cover  64 . The opening  99  exists by virtue of removing at least a portion of the service panel  72 . 
         [0057]      FIG. 6  illustrates another exemplary service panel  172  that may be incorporated into a battery assembly  50 . In this disclosure, like reference numbers designate like elements where appropriate and reference numerals with the addition of  100  or multiples thereof designate modified elements that are understood to incorporate the same features and benefits of the corresponding original elements. 
         [0058]    In this embodiment, the service panel  172  includes a ductile portion  176  that is defined about an outer periphery  169  of a membrane  171 . The ductile portion  176  may include a perforation  173  that weakens the outer periphery  169  such that the membrane  171  can be removed from a cover  164  of the battery assembly  50  to expose a serviceable part  174 . In other words, the membrane  171  can be torn away from the cover  164  by plastically deforming the ductile portion  176  along the perforation  173 . The perforation  173  defines a tear line TL for removing the membrane  171 . The membrane  171  may be frangibly connected to the cover  164  via the tear line TL. 
         [0059]    This disclosure is not necessarily limited to electric vehicle battery enclosure assemblies. Other electric vehicle components may benefit from the service panels described above, including but not limited to, motor inverter/converter systems. In addition, the teachings of this disclosure may be applicable to non-automotive components including any component in which it is desirable to provide access to a serviceable part inside the component. 
         [0060]    For example,  FIG. 7  illustrates an exemplary enclosure assembly  200 . The enclosure assembly  200  includes a housing  202  containing at least one serviceable part  204 . A service panel  206  is integrally formed in the housing  202 . The service panel  206  provides selective access to the serviceable part  204 . 
         [0061]    In one embodiment, the service panel  206  includes a ductile portion  208  that can be plastically deformed to expose the serviceable part  204 . The ductile portion  208  could include a tear strip similar to that described in  FIGS. 2 and 3 , a perforated membrane similar to the one taught in  FIG. 6 , or any other molded-in release feature that permits non-reversible removal of at least a portion of the service panel  206  to expose the serviceable part(s)  204 . 
         [0062]    Although the different non-limiting embodiments are illustrated as having specific components or steps, the embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments. 
         [0063]    It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should be understood that although a particular component arrangement is disclosed and illustrated in these exemplary embodiments, other arrangements could also benefit from the teachings of this disclosure. 
         [0064]    The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. For these reasons, the following claims should be studied to determine the true scope and content of this disclosure.