Abstract:
An exemplary assembly includes an extrusion providing a channel that receives a portion of a battery cell frame. The extrusion is securable to a support to secure the battery cell frame relative to the support.

Description:
TECHNICAL FIELD 
     This disclosure is directed toward retaining areas of a battery pack and, more particularly, to utilizing an extrusion to secure portions of a battery array within a battery pack. 
     BACKGROUND 
     Generally, electrified vehicles differ from conventional motor vehicles because electrified vehicles are selectively driven using one or more battery-powered electric machines. Conventional motor vehicles, by contrast, rely exclusively on an internal combustion engine to drive the vehicle. Electrified vehicles may use electric machines instead of, or in addition to, the internal combustion engine. 
     Example electrified vehicles include hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), fuel cell vehicles, and battery electric vehicles (BEVs). A powertrain of an electrified vehicle is typically equipped with a battery pack having battery cells that store electric power for powering the electric machines. 
     The battery pack can include multiple arrays of battery cells contained within a housing. Securing the arrays can be required. 
     SUMMARY 
     An assembly according to an exemplary aspect of the present disclosure includes, among other things, an extrusion providing a channel that receives a portion of a battery cell frame. The extrusion securable to a support to secure the battery cell frame relative to the support. 
     In a further non-limiting embodiment of the foregoing assembly, the channel slideably receives the portion. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the assembly includes a snap-fit feature that includes a ridge receivable within a groove. The extrusion engages the portion using the snap-fit feature when the channel receives the portion. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the extrusion extends longitudinally along a first axis, and the channel and the groove extend along a second axis aligned with the first axis. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the portion is a foot extending laterally from other portions of the frame. The channel includes an upper retention flange and a lower retention flange extending from a wall. The upper retention flange is positioned against an upwardly facing surface of the foot when the channel receives the foot. The lower retention flange is positioned against a downwardly facing surface of the foot when the channel receives the foot. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the assembly includes a securement flange extending from the wall opposite the upper retention flange and the lower retention flange. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the securement flange includes an aperture to receive a mechanical fastener that secures the extrusion to the structure. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the extrusion is a metallic material. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the assembly includes an end cap, wherein the extrusion extends longitudinally along an axis from a first end portion to an opposing second end portion, the end cap secured to the first end portion to limit movement along the axis of the extrusion relative to the portion. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the extrusion has a “C” shaped cross-sectional profile. 
     An assembly according to another exemplary aspect of the present disclosure includes, among other things, a plurality of battery cells along an axis and a plurality of frames holding one or more of the plurality of battery cells. Each frame includes a first foot extending outwardly from the axis on a first lateral side and a second foot extending outwardly from the axis on an opposite, second lateral side. A first extrusion has a first channel that receives the first feet of the plurality of frames. A second extrusion has a second channel that receives the second feet of the plurality of frames. 
     In a further non-limiting embodiment of the foregoing assembly, the assembly includes a snap-fit feature includes a ridge receivable within a groove. The first extrusion engages the first feet using the snap-fit feature when the channel of the first extrusion receives the first feet. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the first extrusion slideably engages the first feet and the second extrusion slideably engages the second feet 
     In a further non-limiting embodiment of any of the foregoing assemblies, the assembly includes an end cap. The first extrusion extends longitudinally along an axis from a first end portion to an opposing second end portion. The end cap is secured to the first end portion to limit movement along the axis of the first extrusion relative to the first feet. 
     A method of securing portions of a battery pack according to an exemplary aspect of the present disclosure includes, among other things, slidably engaging a portion of a battery cell frame within a channel of an extrusion, and securing the extrusion to a support to secure the battery cell frame. 
     In another example of the foregoing method, the battery cell frame extends about the perimeter of at least one battery cell. 
     In another example of any of the foregoing methods, the portion is a foot extending laterally outward from the remaining portions of the battery support frame. 
     In another example of any of the foregoing methods, the extrusion engages a portion of a plurality of other battery cell frames. 
     In another example of any of the foregoing methods, the method further comprises using the extrusion to limit both upward and downward movement of the battery cell frame. 
     In another example of any of the foregoing methods, the method further comprises snap-fitting the extrusion to the battery cell frame. 
     The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible. 
    
    
     
       DESCRIPTION OF THE FIGURES 
       The various features and advantages of the disclosed examples will become apparent to those skilled in the art from the detailed description. The figures that accompany the detailed description can be briefly described as follows: 
         FIG. 1  is a schematic view of an example powertrain of an electrified vehicle. 
         FIG. 2  is a schematic perspective view of a battery array within powertrain of  FIG. 1 . 
         FIG. 3  is a schematic section view of a battery pack of the powertrain of  FIG. 1  incorporating the battery array of  FIG. 2 . 
         FIG. 4  is a close-up perspective view of example support structures that hold battery cells within the array of  FIG. 2 . 
         FIG. 5  is a perspective view of an example extrusion that secures the battery array of  FIG. 2  within the battery pack of  FIG. 3 . 
         FIG. 6  shows a close-up perspective view of the extrusion of  FIG. 5  securing the battery array of  FIG. 2  within the battery pack of  FIG. 3 . 
         FIG. 7  shows a perspective view of selected portion of the battery pack of  FIG. 3 . 
         FIG. 8  shows a side view of the extrusion of  FIG. 4  disengaged from the battery array of  FIG. 2 . 
         FIG. 9  shows a side view of the extrusion of  FIG. 4  engaged with the battery array of  FIG. 2 . 
         FIG. 10  shows a perspective view of the extrusion of  FIG. 4  engaging the array in a first position. 
         FIG. 11  shows the extrusion of  FIG. 4  engaging the array in a second position. 
     
    
    
     DETAILED DESCRIPTION 
     This disclosure relates generally to an extrusion that secure a battery array within a battery pack. The extrusion provides effective retention within a relatively tight packaging space. 
       FIG. 1  schematically illustrates a powertrain  10  for a hybrid electric vehicle (HEV). The powertrain  10  includes a battery pack  14 , a motor  18 , a generator  20 , and an internal combustion engine  22 . 
     The motor  18  and generator  20  are types of electric machines. The motor  18  and generator  20  may be separate or may have the form of a combined motor-generator. 
     In this embodiment, the powertrain  10  is a power-split powertrain system that employs a first drive system and a second drive system. The first and second drive systems generate torque to drive one or more sets of vehicle drive wheels  26  of the electrified vehicle. The first drive system includes a combination of the engine  22  and the generator  20 . The second drive system includes at least the motor  18 , the generator  20 , and the battery pack  14 . The motor  18  and the generator  20  are portions of an electric drive system of the powertrain  10 . 
     The engine  22 , which is an internal combustion engine in this example, and the generator  20  may be connected through a power transfer unit  30 , such as a planetary gear set. Of course, other types of power transfer units, including other gear sets and transmissions, may be used to connect the engine  22  to the generator  20 . In one non-limiting embodiment, the power transfer unit  30  is a planetary gear set that includes a ring gear  32 , a sun gear  34 , and a carrier assembly  36 . 
     The generator  20  can be driven by engine  22  through the power transfer unit  30  to convert kinetic energy to electrical energy. The generator  20  can alternatively function as a motor to convert electrical energy into kinetic energy, thereby outputting torque to a shaft  38  connected to the power transfer unit  30 . Because the generator  20  is operatively connected to the engine  22 , the speed of the engine  22  can be controlled by the generator  20 . 
     The ring gear  32  of the power transfer unit  30  can be connected to a shaft  40 , which is connected to vehicle drive wheels  26  through a second power transfer unit  44 . The second power transfer unit  44  may include a gear set having a plurality of gears  46 . Other power transfer units may also be suitable. The gears  46  transfer torque from the engine  22  to a differential  48  to ultimately provide traction to the vehicle drive wheels  26 . The differential  48  may include a plurality of gears that enable the transfer of torque to the vehicle drive wheels  26 . In this example, the second power transfer unit  44  is mechanically coupled to an axle  50  through the differential  48  to distribute torque to the vehicle drive wheels  26 . 
     The motor  18  can also be employed to drive the vehicle drive wheels  26  by outputting torque to a shaft  52  that is also connected to the second power transfer unit  44 . In one embodiment, the motor  18  and the generator  20  cooperate as part of a regenerative braking system in which both the motor  18  and the generator  20  can be employed as motors to output torque. For example, the motor  18  and the generator  20  can each output electrical power to the battery pack  14 . 
     Referring now to  FIGS. 2 to 4 , the example battery pack  14  provides a relatively high-voltage battery that stores generated electrical power and outputs electrical power to operate the motor  18 , the generator  20 , or both. 
     The battery pack  14  includes a plurality of arrays  60 . Each of the arrays  60  includes a plurality of individual battery cells  64  held within a support structure  68 . For example, each of the arrays  60  may include from thirty to fifty individual battery cells  64 . The battery cells  64  are distributed along an axis A. 
     The support structure  68  includes, among other things, a battery cell frame  70  about the perimeter of each of the battery cells  64 . Each frame  70  supports two individual battery cells  64  in this example. The frames  70  are a polymer material in this example. 
     The frames  70  and battery cells  64  are held axially between end walls  72 . The frames  70  and the battery cells  64  are held laterally between side walls  74 . 
     The frames  70  are disposed on a cold plate  76 . A coolant can circulates through channels within the cold plate  76  to carry thermal energy from the arrays  60 . Cooling fins (not shown) may be placed between axially adjacent battery cells  64  to communicate thermal energy downward to the cold plate  76 . 
     The battery pack  14  includes a case  80  that houses the arrays  60 . The case includes a lid  82  secured to a floor  84 . 
     In this example, the battery pack  14  includes supports  86  extending longitudinally in a direction aligned with the axis A. The supports  86  are positioned between arrays  60  within the battery pack  14 . The supports  86  have a “U” shaped profile such that an open area  90  can be provided between the supports  86  and the floor  84  when the supports  86  are secured to the floor  84 . The supports  86  can be welded to the floor  84  of the case  80 , for example. 
     The frames  70  include feet  94  extending laterally outward from the axis A. The feet  94  may extend laterally outside the cold plate  70 . 
     To secure the array relative to the case  80 , an extrusion  100  engages the feet  94  on one lateral side of the array  60 . The extrusion  100  is then secured to the support  86  to stabilize the array  60  within the battery pack  14 . The example arrays  60  are secured, through the extrusion  100  and ridge member  86 , to the floor  84  of the case  80 . 
     Referring now to  FIGS. 5 to 11  with continuing reference to  FIGS. 2 and 3 , the example extrusion  100  includes an upper retention flange  104 , a lower retention flange  108 , a wall  112 , and a securement flange  116 . The upper retention flange  104  and the lower retention flange  108  extend in a first direction from the opposing ends of the wall  112  to provide a channel  118 . The securement flange  116  extends from the wall  112  opposite the upper retention flange  104  and the lower retention flange  108 . 
     The shape of the channel  118  corresponds generally to the shape of the feet  94 . The example channel  118  has a “C” shaped cross-sectional profile. 
     When the feet  94  are received within the channel  118 , the upper retention flange  104  is positioned against an upwardly facing surface  120  of the feet  94 , and the lower retention flange  108  is positioned against the downwardly facing surfaces  124  of the feet  94 . 
     The feet  94  and the extrusion  100  include a snap-fit feature  128  to help hold the feet  94  within the channel  118  of the extrusion  100 . The example snap-fit feature  128  includes a ridge  132  and a groove  136 . The ridge  132  extends upwardly from the lower retention flange  108 . The groove  136  is provided within the downwardly facing surface  124  of the feet  94 . When the feet  94  are positioned within the channel  118 , the ridge  132  contacts the sides of the groove  136  to prevent the extrusion  100  from moving laterally outward relative to the feet  94 . 
     The example extrusion  100  extends longitudinally from a first end  140  to an opposing second end  144  along an axis that is generally aligned with the axis A of the array  60 . The extrusion  100  is a metallic material, such as an aluminum. 
     During assembly, the lid  82  is detached from the floor  84  such that the arrays  60  can be positioned within the battery pack  14 . In this example, the feet  94  are positioned within the extrusion  100  prior to positioning the arrays  60  within the pack  14 . Feet on the opposing lateral side of the arrays  60  are positioned within another extrusion. Notable, the extrusion  100  and the other extrusion have a common cross-sectional profile. The same extrusion manufacturing process can thus provide extrusions to engage feet on both sides of the arrays  60 . 
     The extrusion  100  can slideably engage the feet  94  to position the feet  94  within the extrusion.  FIG. 10  shows the extrusion  100  in a partially slid position relative to the feet  94 .  FIG. 11  shows the extrusion  100  in a fully slid position relative to the feet  94 . 
     When the feet  94  are positioned within the extrusion  100 , and the extrusion  100  is axially aligned with the feet  94  as is shown in  FIG. 11 , the arrays  60  are then positioned on the floor  84  of the battery pack  18 . 
     In some examples, after positioning the extrusion  100  on the feet  94  as shown in  FIG. 11 , end caps  158  are secured to the first end  140  and the second end  144  to prevent movement of the extrusion  100  relative to the feet  94  along the axis as the array  60  is positioned upon the floor  84 . The end caps  158  are welded to the extrusion  100 , for example. 
     The securement flange  116  provides apertures  160  corresponding to apertures  164  provided within the supports  86 . The arrays  60  and the extrusion  100  are positioned within the battery pack  18  such that the apertures  160  and  164  are aligned. A mechanical fastener  168  is the positioned within the apertures  160  and  164  to hold the extrusion  100  relative to the supports  86 . A lock nut may be welded to the supports  86  within the open area  90  provide a threaded connection to the fastener  168 . 
     When the extrusion  100  is secured to the supports  86 , the extrusion  100  limits vertical movements of the array  60 . Vertical upward movement of the array  60  is limited by the upwardly facing surface  120  contacting the upper retention flange  104 . Movements of array  60  along the axis A are limited by the end walls  72 . 
     Features of the disclosed examples include a retention strategy for arrays within a battery pack. The retention strategy is cost-effective and provides retention within relatively tight packaging areas. Using the extrusion for retention may reduce labor time for installation compared to other conventional fastening methods. The thicknesses of the extrusion can be adjusted at various axial positions if local strengthening is required. Cost and time for developing a retention feature for the battery pack is also reduced. 
     The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. Thus, the scope of legal protection given to this disclosure can only be determined by studying the following claims.