Protective cage assemblies for electrified vehicle battery packs

A protective cage assembly includes a frame, a bracket assembly mounted to a first tubular member of the frame, a gusset of the bracket assembly extending between the bracket assembly and a second tubular member of the frame, and a third tubular member of the frame removably received by the bracket assembly. The protective cage assembly may be mounted within a cargo space of an electrified vehicle for both protecting the battery pack and establishing a load bearing floor of the cargo space.

TECHNICAL FIELD

This disclosure relates to cage assembles for protecting electrified vehicle battery packs during impact events.

BACKGROUND

The desire to reduce automotive fuel consumption and emissions has been well documented. Therefore, electrified vehicles are being developed that reduce or completely eliminate reliance on internal combustion engines. In general, electrified vehicles differ from conventional motor vehicles because they are selectively driven by one or more battery powered electric machines. Conventional motor vehicles, by contrast, rely exclusively on the internal combustion engine to propel the vehicle.

A high voltage traction battery pack typically powers the electric machines and other electrical loads of the electrified vehicle. The battery pack includes a plurality of energy storage devices, such as battery cells, that store energy for powering these electrical loads. The battery cells and various other battery components are typically packaged together inside an enclosure assembly. Depending on where it is mounted on the vehicle, the battery pack may be susceptible to damage during vehicle impact events.

SUMMARY

A protective cage assembly according to an exemplary aspect of the present disclosure includes, among other things, a frame, a bracket assembly mounted to a first tubular member of the frame, a gusset of the bracket assembly extending between the bracket assembly and a second tubular member of the frame, and a third tubular member of the frame removably received by the bracket assembly.

In a further non-limiting embodiment of the foregoing assembly, the first tubular member is a longitudinally extending tubular member, the second tubular member is a vertically extending tubular member, and the third tubular member is a laterally extending tubular member.

In a further non-limiting embodiment of either of the foregoing assemblies, the frame includes a plurality of tubular members that are connected together to form a rectangular shape.

In a further non-limiting embodiment of any of the foregoing assemblies, a load bearing floor is secured to the third tubular member.

In a further non-limiting embodiment of any of the foregoing assemblies, the frame includes a lower frame portion, an upper frame portion, and an intermediate frame portion.

In a further non-limiting embodiment of any of the foregoing assemblies, a first floor panel of a load bearing floor is secured to the upper frame portion, and a second floor panel of the load bearing floor is secured to the intermediate frame portion.

In a further non-limiting embodiment of any of the foregoing assemblies, the upper frame portion and the intermediate frame portion establish a stepped upper section of the frame.

In a further non-limiting embodiment of any of the foregoing assemblies, the upper frame portion extends a first height above the lower frame portion and the intermediate frame portion extends a second, shorter height above the lower frame portion.

In a further non-limiting embodiment of any of the foregoing assemblies, the bracket assembly includes a U-shaped bracket, and the third tubular member is slidingly received within the U-shaped bracket.

In a further non-limiting embodiment of any of the foregoing assemblies, the gusset extends from the U-shaped bracket to the second tubular member.

An electrified vehicle according to another exemplary aspect of the present disclosure includes, among other things, a drive wheel, a cargo space, a battery pack positioned within the cargo space and adapted to selectively supply power for propelling the drive wheel, and a protective cage assembly configured to protect the battery pack and establish a load bearing floor of the cargo space.

In a further non-limiting embodiment of the foregoing electrified vehicle, the electrified vehicle is a van.

In a further non-limiting embodiment of either of the foregoing electrified vehicles, the battery pack is mounted to an upper surface of a floor pan of the electrified vehicle.

In a further non-limiting embodiment of any of the foregoing electrified vehicles, the battery pack houses at least one battery array.

In a further non-limiting embodiment of any of the foregoing electrified vehicles, the protective cage assembly surrounds and partially encloses the battery pack.

In a further non-limiting embodiment of any of the foregoing electrified vehicles, the protective cage assembly includes a frame constructed of a plurality of longitudinally extending tubular members, a plurality of laterally extending tubular members, and a plurality of vertically extending tubular members.

In a further non-limiting embodiment of any of the foregoing electrified vehicles, at least one of the plurality of laterally extending tubular members is removable from the frame.

In a further non-limiting embodiment of any of the foregoing electrified vehicles, the protective cage assembly includes a lower frame portion, an upper frame portion, and an intermediate frame portion.

In a further non-limiting embodiment of any of the foregoing electrified vehicles, the load bearing floor includes a first floor panel secured to the upper frame portion and a second floor panel secured to the intermediate frame portion.

In a further non-limiting embodiment of any of the foregoing electrified vehicles, the upper frame portion extends to a first height that is equal to a second height of a folded seat located within a passenger cabin that is connected to the cargo space.

DETAILED DESCRIPTION

This disclosure details electrified vehicles that are equipped with protective cage assembles for protecting battery packs during vehicle impact events. An exemplary protective cage assembly includes a frame and a bracket assembly secured to the frame. A tubular member of the frame may be removably received by the bracket assembly. The protective cage assembly may be mounted within a cargo space of an electrified vehicle for both protecting the battery pack and establishing a load bearing floor of the cargo space. These and other features are discussed in greater detail in the following paragraphs of this detailed description.

FIG. 1schematically illustrates a powertrain10for an electrified vehicle12. Although depicted as a hybrid electric vehicle (HEV), it should be understood that the concepts described herein are not limited to HEVs and could extend to other electrified vehicles, including, but not limited to, plug-in hybrid electric vehicles (PHEV's), battery electric vehicles (BEVs), fuel cell vehicles, etc.

In an embodiment, the powertrain10is a power-split powertrain system that employs first and second drive systems. The first drive system includes a combination of an engine14and a generator18(i.e., a first electric machine). The second drive system includes at least a motor22(i.e., a second electric machine), the generator18, and a battery pack24. In this example, the second drive system is considered an electric drive system of the powertrain10. The first and second drive systems are each capable of generating torque to drive one or more sets of vehicle drive wheels28of the electrified vehicle12. Although a power-split configuration is depicted inFIG. 1, this disclosure extends to any hybrid or electric vehicle including full hybrids, parallel hybrids, series hybrids, mild hybrids, or micro hybrids.

The engine14, which may be an internal combustion engine, and the generator18may be connected through a power transfer unit30, 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 engine14to the generator18. In a non-limiting embodiment, the power transfer unit30is a planetary gear set that includes a ring gear32, a sun gear34, and a carrier assembly36.

The generator18can be driven by the engine14through the power transfer unit30to convert kinetic energy to electrical energy. The generator18can alternatively function as a motor to convert electrical energy into kinetic energy, thereby outputting torque to a shaft38connected to the power transfer unit30. Because the generator18is operatively connected to the engine14, the speed of the engine14can be controlled by the generator18.

The ring gear32of the power transfer unit30may be connected to a shaft40, which is connected to vehicle drive wheels28through a second power transfer unit44. The second power transfer unit44may include a gear set having a plurality of gears46. Other power transfer units may also be suitable. The gears46transfer torque from the engine14to a differential48to ultimately provide traction to the vehicle drive wheels28. The differential48may include a plurality of gears that enable the transfer of torque to the vehicle drive wheels28. In a non-limiting embodiment, the second power transfer unit44is mechanically coupled to an axle50through the differential48to distribute torque to the vehicle drive wheels28.

The motor22can also be employed to drive the vehicle drive wheels28by outputting torque to a shaft52that is also connected to the second power transfer unit44. In a non-limiting embodiment, the motor22and the generator18cooperate as part of a regenerative braking system in which both the motor22and the generator18can be employed as motors to output torque. For example, the motor22and the generator18can each output electrical power to the battery pack24.

The battery pack24is an exemplary electrified vehicle battery. The battery pack24may be a high voltage traction battery that includes a plurality of battery arrays25(i.e., battery assemblies or groupings of battery cells) capable of outputting electrical power to operate the motor22, the generator18, and/or other electrical loads of the electrified vehicle12for providing power to propel the wheels28. Other types of energy storage devices and/or output devices could also be used to electrically power the electrified vehicle12.

In an embodiment, the electrified vehicle12has two basic operating modes. The electrified vehicle12may operate in an Electric Vehicle (EV) mode where the motor22is used (generally without assistance from the engine14) for vehicle propulsion, thereby depleting the battery pack24state of charge up to its maximum allowable discharging rate under certain driving patterns/cycles. The EV mode is an example of a charge depleting mode of operation for the electrified vehicle12. During EV mode, the state of charge of the battery pack24may increase in some circumstances, for example due to a period of regenerative braking. The engine14is generally OFF under a default EV mode but could be operated as necessary based on a vehicle system state or as permitted by the operator.

The electrified vehicle12may additionally operate in a Hybrid (HEV) mode in which the engine14and the motor22are both used for vehicle propulsion. The HEV mode is an example of a charge sustaining mode of operation for the electrified vehicle12. During the HEV mode, the electrified vehicle12may reduce the motor22propulsion usage in order to maintain the state of charge of the battery pack24at a constant or approximately constant level by increasing the engine14propulsion. The electrified vehicle12may be operated in other operating modes in addition to the EV and HEV modes within the scope of this disclosure.

FIG. 2illustrates an electrified vehicle12that may employ the powertrain10shown inFIG. 1or any other electrified or hybridized powertrain. In an embodiment, the electrified vehicle12is a van. However, the electrified vehicle12could be a car, a truck, a sport utility vehicle, or any other vehicle type. Although a specific component relationship is illustrated in the figures of this disclosure, the illustrations are not intended to limit this disclosure. The placement and orientation of the various components of the electrified vehicle12are shown schematically and could vary within the scope of this disclosure. In addition, the various figures accompanying this disclosure are not necessarily to scale, and some features may be exaggerated or minimized to show certain details of a particular component.

The electrified vehicle12includes a cargo space54for storing and hauling cargo at a rear location of the electrified vehicle12. The cargo space54is located in a rear portion of the passenger cabin56of the electrified vehicle12, in this embodiment.

Referring now toFIGS. 2 and 3, a battery pack24may be mounted to a floor pan58that extends within the cargo space54. The floor pan58is part of the structural body of the electrified vehicle12. In an embodiment, the battery pack24is mounted to an upper surface60of the floor pan58. The battery pack24may be secured to the floor pan58using any fastening method, including but not limited to bolting, strapping, welding, etc.

The battery pack24may house a plurality of battery cells that store energy for powering various electrical loads of the electrified vehicle12, such as the motor22(seeFIG. 1), for example. The battery cells may be grouped together in one or more battery arrays (shown schematically inFIG. 1as feature25). In an embodiment, the battery pack24houses prismatic, lithium-ion cells. However, battery cells having other geometries (cylindrical, pouch, etc.), other chemistries (nickel-metal hydride, lead-acid, etc.), or both could alternatively be utilized within the scope of this disclosure. The battery pack24may additionally house various other components, including but not limited to, a bussed electrical center (BEC), a battery electric control module (BECM), wiring harnesses, wiring, I/O connectors, etc.

A protective cage assembly62may additionally be mounted to the upper surface60of the floor pan58. The protective cage assembly62is positioned to surround and partially enclose the battery pack24, thereby protecting the battery pack24from deformation during impact events, such as vehicle collisions. For example, during a vehicle impact event (e.g., front, side, rear, side pole, etc.), one or more forces F may act upon the electrified vehicle12. The protective cage assembly62is designed to minimize the amount of energy that is transferred to the battery pack24during the vehicle impact event.

FIGS. 4 and 5illustrate additional features of the exemplary protective cage assembly62. The battery pack24is removed from these figures to better illustrate the various features of the protective cage assembly62.

The protective cage assembly62may include a frame64that is made up of a plurality of tubular members66. The plurality of tubular members66may be arranged longitudinally (see, e.g., tubular members66-LON), laterally (see, e.g., tubular members66-LAT), and vertically (see, e.g., tubular members66-VER) relative to the floor pan58and may be connected together to establish the frame64. In an embodiment, the plurality of tubular members66are welded together. In another embodiment, the plurality of tubular members66are fixated together using mechanical fasteners.

The frame64may be generally rectangular in shape, and each of the tubular members66may be constructed of a metallic material or a combination of metallic materials. However, the actual size, shape, and material makeup of the frame64are not intended to limit this disclosure.

The frame64may include a lower frame portion68, an upper frame portion70, and an intermediate frame portion72. Two or more of the vertically extending tubular members66-VER extend between the lower frame portion68and each of the upper frame portion70and the intermediate frame portion72. In an embodiment, the upper frame portion70is positioned at a first height H1above the lower frame portion68and the intermediate frame portion72is positioned at a second, shorter height H2above the lower frame portion68. The upper frame portion70and the intermediate frame portion72therefore establish a stepped upper section of the frame64.

In another embodiment, the height H1of the upper frame portion70is about equal to a height H3of a folded position of a passenger seat (or seats)74of the electrified vehicle12. In this way, the folded passenger seat(s)74and the upper frame portion70of the frame64cooperate to provide a level surface for storing cargo within the cargo space54.

The lower frame portion68establishes a base of the protective cage assembly62and may include two or more longitudinally extending tubular members66-LON and two or more laterally extending tubular members66-LAT. The lower frame portion68may additionally include one or more mounting brackets76for securing the frame64to the floor pan58. In an embodiment, one mounting bracket76is provided at each corner of the lower frame portion68.

The upper frame portion70and the intermediate frame portion may also each include two or more longitudinally extending tubular members66-LON and two or more laterally extending tubular members66-LAT. The total number of tubular members66-LON,66-LAT, and66-VER utilized to construct the frame64may vary and is dependent on the size of the cargo space54and the size of the battery pack24, among other design criteria.

Referring now primarily toFIG. 5, the protective cage assembly62may additionally include a load bearing floor78that is securable to the frame64. In an embodiment, the load bearing floor78includes a plurality of floor panels80that may be secured to portions of the frame64for storing cargo at a location above the battery pack24. The floor panels80may be made of plywood or any other material that is of sufficient strength to support cargo on top of the protective cage assembly62.

In an embodiment, the load bearing floor78includes a first floor panel80A secured to the upper frame portion70, a second floor panel80B secured to the vertically extending tubular members66-VER that extend between the lower frame portion68and the upper frame portion70on the side of the upper frame portion70that is adjacent to the intermediate frame portion72, a third floor panel80C secured to the intermediate frame portion72, and a fourth floor panel80D secured to the vertically extending tubular members66-VER that extend between the lower frame portion68and the intermediate frame portion72at a rearmost location of the frame64. Other configuration are contemplated within the scope of this disclosure.

The floor panels80may be secured to the various tubular members66of the frame64using one or more fasteners82, such as threaded fasteners. In an embodiment, at least a portion of the tubular members66include imbedded receiving nuts84(seeFIG. 4) for receiving the fasteners82.

It may be desirable to remove portions of the frame64of the protective cage assembly62in order to repair or replace the battery pack24. To achieve this objective, one or more of the tubular members66may be selectively removed from the frame64. For example, as shown inFIGS. 6A and 6B, one or more of the laterally extending tubular members66-LAT may be removably secured to the frame64using bracket assemblies86. Each bracket assembly86may include a U-shaped bracket88and a gusset90. In an embodiment, the U-shaped bracket88may be secured to a longitudinally extending tubular member66-LON, and the gusset90, which may be a triangular shaped reinforcement, may extend between the U-shaped bracket88and a vertically extending tubular member66-VER. A laterally extending tubular member66-LAT (seeFIG. 6B) may be slid downwardly into the U-shaped bracket88when assembling the upper frame portion68and the intermediate frame portion72of the frame64. The tubular member66-LAT can easily be removed by sliding the laterally extending tubular member66-LAT upwardly out of the U-shaped bracket88.

Referring now toFIGS. 7 and 8, the protective cage assembly62may additionally protect portions of a thermal management system associated with the battery pack24. For example, the upper frame portion70may cover portions of inlet ducting92that extends between a vent panel94and the front of the protective cage assembly62(see, e.g.,FIG. 7), and the intermediate frame portion70may cover portions of an outlet duct96that extends through a side of the frame64near the rear of the protective cage assembly62(see, e.g.,FIG. 8). In the illustrated embodiment, air circulating within the passenger cabin56may enter the inlet ducting92through the vent panel94, pass through the battery pack24for removing heat from the battery pack24, and then be expelled to the vehicle exterior through the outlet duct96.