Mounting brackets for a vehicle traction battery system

A mounting bracket is provided for a vehicle battery system with a battery tray sized to receive a traction battery. The bracket has first and second sides extending between first and second ends. The bracket defines first and second apertures adjacent to the first end and positioned to cooperate with the first and second bosses to connect the bracket to the battery tray. The bracket defines a third aperture adjacent to the second end and positioned to cooperate with a mounting point on a vehicle frame. The bracket defines a transverse slot intersecting the first side and extending towards the second side, with the transverse slot positioned between the first and third apertures. A vehicle and a vehicle battery system with the mounting bracket are also provided.

TECHNICAL FIELD

Various embodiments relate to a vehicle traction battery mounting system, and mounting brackets for use with the system.

BACKGROUND

Vehicles may include one or more traction batteries, such as a high voltage battery, to provide electrical power for an electric machine or electric motor to propel the vehicle. The traction battery may be connected to the vehicle frame or body using a battery tray and mounting brackets.

SUMMARY

According to an embodiment, a vehicle battery system includes a battery tray sized to receive a traction battery and defining first and second bosses, and a bracket. The bracket has first and second sides extending between first and second ends. The bracket defines first and second apertures adjacent to the first end and positioned to cooperate with the first and second bosses to connect the bracket to the battery tray. The bracket defines a third aperture adjacent to the second end and positioned to cooperate with a mounting point on a vehicle frame. The bracket defines a transverse slot intersecting the first side and extending towards the second side, with the transverse slot positioned between the first and third apertures.

According to another embodiment, a vehicle is provided with a vehicle frame defining first and second mounting points, a battery tray, a first bracket, and a second bracket. The battery tray is sized to receive a traction battery and defines a first pair of bosses and a second pair of bosses. The first bracket has first and second sides extending between first and second ends. The first bracket defines a pair of apertures adjacent to the first end and positioned to cooperate with the first pair of bosses to connect the bracket to the battery tray. The first bracket defines another aperture adjacent to the second end and positioned to cooperate with the first mounting point. The first bracket defines a transverse slot intersecting the first side and extending towards the second side, with the transverse slot positioned between the pair of apertures and the another aperture. The second bracket has first and second sides extending between first and second ends. The second bracket defines a pair of apertures adjacent to the first end and positioned to cooperate with the first pair of bosses to connect the bracket to the battery tray. The second bracket defines another aperture adjacent to the second end and positioned to cooperate with the second mounting point.

According to yet another embodiment, a mounting bracket for a traction battery tray is provided with a member having first and second sides extending between first and second ends. The member defines a pair of apertures adjacent to the first end to connect the member to a battery tray, another aperture adjacent to the second end to connect the member to a vehicle frame, and a transverse slot intersecting the first side and extending towards the second side.

DETAILED DESCRIPTION

FIG. 1illustrates a partial view of a vehicle10with a vehicle frame12and a vehicle battery system14connected to the vehicle frame12, andFIG. 2illustrates the battery system14. The battery system14includes a battery tray16that is sized to receive a traction battery17for the vehicle10, and may define a recess sized to receive the battery17. The battery tray16may also be referred to as a housing or an enclosure.

In one example, the traction battery17is a battery that provides electrical power to one or more electric machines to propel the vehicle10. The traction battery17may be a high voltage battery, and may be used on a hybrid vehicle, an electric vehicle, a plug-in hybrid vehicle, a micro-hybrid or mild hybrid vehicle, a fuel cell vehicle, and the like. The traction battery17may provide a high voltage direct current (DC) output from one or more battery cell arrays, or battery cell stacks, within the traction battery. The battery cell arrays may include one or more battery cells.

The tray16may be configured to structurally support the traction battery17relative to the frame12and provide a housing with stiffness and durability about the traction battery during normal vehicle operation. Further, in the event of a load applied to the battery system14, for example a vehicle side impact, energy may be transferred from the vehicle frame12to the battery tray16and battery17, and the tray may protect the battery as well as absorb energy from the load or impact.

The battery tray16defines bosses18for use in connecting the battery tray16to the vehicle. In one example, a boss18is provided by a projection, such as a cylindrical or other shaped projection, from the battery tray16, with a contact face surrounding a threaded aperture sized to receive a fastener such as a bolt. In another example, a boss18on the tray16may be defined by a contact face on the main body of the tray and surrounding a threaded aperture sized to receive a fastener such as a bolt, and without a projection from the tray. In various examples, the battery tray14may be formed from a first material, such as an aluminum or an aluminum alloy, and may be formed as a cast aluminum battery tray. The battery tray16may be formed from a cast aluminum material to reduce weight for the vehicle and based on manufacturability considerations.

The battery system14also includes mounting brackets20to connect the tray16to the frame12. Each bracket20may be formed from a second material, such as steel or an extruded aluminum. The tray16may therefore be more brittle than the brackets20.

Each bracket20connects to one or more respective bosses18on the battery tray16and also connects to one or more mounting points22on the vehicle frame12. The vehicle frame12may define mounting points22as apertures in the frame. The vehicle frame12may also define locating features24, which also may be provided by apertures in the frame, to locate the bracket20and battery system14relative to the frame during installation or assembly.

FIG. 1illustrates the battery system14as being connected to a vehicle frame12underbody or undercarriage. The vehicle frame12may be provided by a chassis rail system, a vehicle unibody frame, or a combination thereof. The vehicle frame12as oriented inFIG. 1has a front end30, a rear end32, and left- and right-hand sides34,36based on a normal driving configuration for the vehicle.

The battery system14inFIGS. 1 and 2is positioned between one of the sides34and a vehicle longitudinal axis38, and may be positioned between one of the sides34and a tunnel structure40formed by the frame12along the vehicle longitudinal axis38. The tray16of the battery system as shown inFIGS. 1 and 2has a front end50associated with the front end of the vehicle30, a rear end52associated with the rear end32of the vehicle, an outboard side54associated with and adjacent to the left side34of the vehicle, and an inboard side56adjacent to the tunnel40or vehicle longitudinal axis38.

In other embodiments, and as contemplated by the disclosure, the vehicle battery system14may be connected at another location within the vehicle10, for example, within a rear trunk enclosure, under a vehicle passenger seat, or in another impact zone of the vehicle.

As the battery tray16is may be formed from a cast aluminum material, the battery tray and the associated bosses may be more brittle than the brackets20that are formed from a steel or extruded aluminum. As such, the bosses18are more likely to fracture than the brackets20, for example, during a high load event or an impact. The brackets20as described herein for the battery system14allow the battery tray16to move relative to the vehicle frame12by selective use of flexible brackets, or slotted brackets that are designed to deform under load or impact without fracturing. As the slotted brackets20deform under impact, the stress imparted to the bosses18on the tray16is reduced and distributed.

The brackets20of the battery system14also sufficient stiffness for the battery system to meet the noise, vibration, and harshness requirements for the vehicle10, as well as durability requirements. Testing has indicated that the brackets20according to the present disclosure meet the same NVH and durability targets as a set of conventional brackets without slots.

By using a battery system14with brackets20as described herein, the battery system may be mounted in locations on the vehicle10that were otherwise unavailable for locating a battery, e.g. in an impact zone, as the brackets20allow for the battery tray16and battery to remain attached to the vehicle under an impact and while reducing stress to the battery tray under load. InFIG. 1, the brackets20allow for the battery system16to be mounted within a side impact deformation zone of the vehicle. In other examples, the brackets20allow the battery system14to be mounted in other impact zones of the vehicle, thereby expanding the possible mounting locations and packaging solutions on the vehicle for the battery system. The brackets20may also provide for use of the battery system on multiple vehicle platforms.

As shown inFIGS. 1 and 2, the battery system14has multiple brackets20, with the brackets being provided in different forms. In the example shown, the battery system14has a first bracket60along the outboard side54, a pair of second brackets62along the inboard side56, a third bracket64along the front end50, and a fourth bracket66along the rear end52. The brackets20cooperate to connect the battery tray16and battery to the vehicle10. In other examples, other numbers of brackets20may be used, and the battery system may use a greater number or fewer number of forms or shapes of brackets. In the various examples, the battery system14includes at least one bracket60,62with a slot and at least one bracket64,66without a slot as described herein.

In the event of a side impact to the left side34of the vehicle10, as indicated by arrow F, a force is imparted onto the battery tray16and battery and the battery tray and battery react by moving along the impact axis. As such the slotted brackets60,62are positioned on the sides of the battery tray16that receive or intersect the impact axis and impact load, or a majority of the impact load. For the example shown and with respect to the battery tray16being positioned in a side impact zone as shown inFIG. 1, the slotted brackets60,62are therefore positioned on the inboard and outboard sides54,56of the battery tray, and the unslotted brackets64,66are positioned on the front and rear ends50,52of the battery tray16.

For a side impact as described above, the bracket60on the side receiving the impact is compressed, and the slot allows the bracket60to deform leading to a crumpling of the bracket60and also some rotation of the bracket60. The brackets62on the opposed side from the impact and along the impact axis undergo tension, and deform to elongate and stretch. Additionally, based on the impact, the tunnel section40may deform and crumple, causing further tension on the brackets62and bracket62deformation and elongation. Regardless of deformation of the brackets, the brackets60,62are configured such that they maintain a connection between the vehicle frame12and the battery tray16, and the brackets60,62do not fracture, separate, or rupture during an impact, the deformation absorbs load, and the brackets60,62provides stress relief and distribution of force to the tray.

In other examples, the battery system14may be positioned in another vehicle location, and the brackets60,62may be rearranged based on an associated impact direction for that region of the vehicle.

FIG. 3illustrates another view of the bracket60inFIG. 2. The bracket60is provided by a member with first and second sides80,82extending between first and second ends84,86. The bracket has at least one aperture88adjacent to the first end84to cooperate with a boss18on the battery tray16. In the example shown, the bracket has first and second apertures88, or a pair of apertures, adjacent to the first end84and positioned to cooperate with the first and second bosses18on the tray to connect the bracket to the battery tray. First and second fasteners90, such as bolts, are provided as shown inFIG. 2. The first fastener90cooperates with the first boss18and the first aperture88, and the second fastener90cooperates with the second boss18and the second aperture88to connect the bracket60to the battery tray16.

The bracket60also defines another aperture92, or a third aperture, adjacent to the second end86and positioned to cooperate with a mounting point22on a vehicle frame12. A third fastener94, such as a bolt, is shown inFIG. 1. The third fastener94cooperates with the third aperture92and the mounting point22to connect the bracket to the vehicle frame. The bracket60may be connected to the vehicle frame12using only the third fastener94. The bracket60is the sole bracket connected to the first and second bosses18, e.g. the bracket does not have another component or portion.

The bracket60defines a first region100adjacent to the first end84and containing the first and second apertures88. The bracket60also defines a second region102adjacent to the second end86and containing the third aperture92. The bracket60defines a third region104extending between the first and second regions100,102and containing a transverse slot106. Each of the first, second, and third regions100,102,104may be substantially planar. The first and second regions100,102are spaced apart and substantially parallel to one another. For purposes of this disclosure, substantially refers to being within plus or minus ten degrees of a specified orientation, or being within plus or minus five degrees of a specified orientation. The third region104may be angled relative to the first and second regions100,102, such that the bracket has an S-shape or Z-shape overall.

The bracket member60also defines a transverse slot106intersecting the first side80and extending towards and spaced apart from the second side82. The transverse slot106is positioned between the first and third apertures88,92. In one example, and as shown, the transverse slot106is defined by first and second side walls108,110connected by an end wall112. The first and second side walls108,110intersect the first side80of the bracket. The first and second side walls108,110of the transverse slot may be parallel to one another. Furthermore, the first and second side walls108,110of the transverse slot may be perpendicular or substantially perpendicular to the first side80of the bracket in the region of their intersection therewith.

The end wall112of the transverse slot is formed by a continuous concave curve extending between the first and second side walls108,110according to the example shown. In one example, the curve may have a constant radius of curvature along its length, with the first and second sides108,110of the transverse slot smoothly blending into the end wall112or extending tangentially to the end wall. The transverse slot106may extend across the bracket60such that the end wall112of the transverse slot is in alignment with an edge of the third aperture92closest to a longitudinal axis114of the bracket or the edge of the aperture92farthest from the second side82. In other examples, the transverse slot106may have another shape, and extend across another percentage of the width of the bracket60.

FIG. 4illustrates another view of the bracket62inFIG. 2. The bracket62is provided by a member with first and second sides120,122extending between first and second ends124,126. The bracket has at least one aperture128adjacent to the first end124to cooperate with a boss18on the battery tray. In the example shown, the bracket62has first and second apertures128, or a pair of apertures, adjacent to the first end124and positioned to cooperate with a pair of bosses18on the tray to connect the bracket to the battery tray. A pair of fasteners130, such as bolts, are provided as shown inFIG. 2and cooperate with the bosses18and first and second apertures128to connect the bracket62to the battery tray16.

The bracket62also defines another aperture132, or a third aperture, adjacent to the second end126and positioned to cooperate with a mounting point22on a vehicle frame12. A third fastener134, such as a bolt, is shown inFIG. 1. The third fastener134cooperates with the third aperture132and the mounting point22to connect the bracket62to the vehicle frame12. The bracket62may be connected to the vehicle frame12using only the third fastener134. The bracket62is the sole bracket connected to the first and second bosses18, e.g. the bracket does not have another component or portion.

The bracket62also defines a fourth aperture136positioned adjacent to the second end126and adjacent to the third aperture132. The fourth aperture136is sized to locate the bracket62relative to the vehicle frame12by way of a locating feature24on the vehicle frame. The fourth aperture136may be provided with a non-circular shape in some examples.

The bracket62defines a first region140adjacent to the first end124and containing the first and second apertures128. The bracket62also defines a second region142adjacent to the second end126and containing the third aperture132and the fourth aperture136. The bracket62defines a third region144extending between the first and second regions140,142and containing a transverse slot146. Each of the first, second, and third regions140,142,144may be substantially planar. The first and second regions140,142are spaced apart and substantially parallel to one another. The third region144may be angled relative to the first and second regions, such that the bracket has an S-shape or Z-shape overall.

The bracket member62also defines a transverse slot146intersecting the first side120and extending towards and spaced apart from the second side122. The transverse slot146is positioned between the first and third apertures128,132. In one example, and as shown, the transverse slot146is defined by first and second side walls148,150connected by an end wall152. The first and second side walls148,150intersect the first side120of the bracket. The first and second side walls148,150of the transverse slot may be parallel to one another. Furthermore, the first and second side walls148,150of the transverse slot may be perpendicular or substantially perpendicular to the first side120of the bracket in the region of their intersection therewith.

The end wall152of the transverse slot146is formed by a continuous concave curve extending between the first and second side walls148,150according to the example shown. In one example, the curve may have a constant radius of curvature along its length, with the first and second sides148,150of the transverse slot smoothly blending into the end wall152or extending tangentially to the end wall. The transverse slot146may extend across the bracket62such that the end wall152of the transverse slot is in alignment with an edge of the third aperture132closest to a longitudinal axis154of the bracket or the edge of the third aperture to the second side122and fourth aperture136. In another example, the transverse slot146extends across the bracket such that the end wall152of the transverse slot is positioned between the third and fourth apertures132,136. In other examples, the transverse slot146may have another shape, and extend across another percentage of the width of the bracket.

Referring back toFIG. 2, the third and fourth brackets64,66are connected to the front and rear ends50,52of the battery tray16, respectively. The third and fourth brackets64,66are provided on sides of the battery tray16that are not associated with a load path or impact path F. Each of the third and fourth brackets64,66has first and second sides160,162extending between first and second ends164,166. Each of the third and fourth brackets64,66is without a transverse slot or other cutout or relief section to provide a deformation zone on the bracket. In other examples, more than one bracket per associated side may be used.

Each of the third and fourth brackets64,66defines at least one aperture170adjacent to the first end164and positioned to cooperate with at least one boss18on the battery tray to connect the bracket to the battery tray. In the example shown, each of the third and fourth brackets64,66defines three apertures170adjacent to the first end to connect to three bosses, respectively, via fasteners. In other examples, each of the third and fourth brackets may be provided with a pair of apertures170adjacent to the first end.

Each of the third and fourth brackets64,66also defines an aperture172adjacent to the second end166and positioned to cooperate with a mounting point22on the vehicle frame to connect the bracket to the vehicle frame. The aperture166may provide the sole mounting point for the bracket64,66to the vehicle frame. One or both of the brackets may additionally be provided with an additional aperture174sized to locate the bracket relative to the vehicle frame by way of a locating feature24on the vehicle frame. The additional aperture174may be provided with a non-circular shape in some examples. The additional aperture174does not receive a fastener when the bracket is connected to the vehicle frame12.

The battery system14and associated brackets20allow for mounting of a traction battery17on a vehicle10that meets NVH and durability requirements, while also allowing for greater availability of packaging locations on the vehicle, including within or near an impact zone. The combination of slotted and unslotted brackets60,62,64,66helps to retain the battery tray16and battery to the vehicle frame12under a load such as an impact load. Additionally, the slotted brackets60,62allow for movement in the battery tray relative to the vehicle frame under a load or force, and the slotted regions provide a deformation zone that allows for elongation or crumpling of the bracket without the bracket fracturing or the battery tray bosses fracturing, thus maintaining a continuous connection between the vehicle frame and the battery tray. The bosses18on the battery tray may be formed from a material that is more brittle than the brackets20, such as a cast aluminum tray and a steel or extruded aluminum bracket. The slotted brackets60,62disrupt the direct load path from vehicle frame12fastener to the tray boss18fastener, and provides stress relief on the associated boss18. The slots in the brackets60,62provide stress relief for and movement of the battery tray, while the unslotted brackets64,66away from the load path F provide a secure connection between the frame12and the tray16.

The brackets20each have greater number of apertures to mount the bracket to the battery tray16than apertures to mount the bracket to the vehicle frame12. A load from the vehicle frame12to the bracket20is therefore distributed across multiple fasteners at the battery tray16end, and further lowers the load and stress on each of the battery tray bosses18.