Traction battery bus bar assembly locking bar

Abstract

The present disclosure provides a traction battery bus bar assembly locking bar. A traction battery pack assembly includes a bus bar assembly having a frame and at least one bus bar. The frame includes a plurality of fingers. A locking bar has a plurality of apertures each configured to receive a portion of one or more of the fingers to constrain the bus bar assembly.

Description

Technical Field

[0001] The present disclosure generally relates to the use of locking bars to restrain movement, and particularly vibration, of a bus bar assembly of a traction battery pack. Background Art

[0002] Electrified vehicles differ from conventional motor vehicles in that they can be selectively driven by one or more electric motors powered by a traction battery pack. The electric motors can propel the vehicle in place of, or in combination with, an internal combustion engine. The traction battery pack discharges while powering the electric motor or motors and other loads in the electrified vehicle. Summary of the Invention

[0003] In some aspects, the technology described herein relates to a traction battery pack assembly comprising: a bus bar assembly having a frame and at least one bus bar, the frame including a plurality of fingers; and a locking bar having a plurality of apertures each configured to receive a portion of one or more of the fingers to constrain the bus bar assembly.

[0004] In some aspects, the technology described herein relates to a traction battery pack assembly in which the bus bar assembly is pivotally coupled to a cover that spans a battery cell stack.

[0005] In some aspects, the technology described herein relates to a traction battery pack assembly, wherein the locking bar is a first locking bar and the plurality of holes is a first plurality of holes, the bus bar assembly is a first bus bar assembly pivotally coupled to a first side of the cover, the frame is a first frame, the plurality of fingers is a first plurality of fingers, and the traction battery pack assembly further comprises: a second bus bar assembly and a second locking bar, the second bus bar assembly having a second frame with a second plurality of fingers and at least one second bus bar, the second locking bar having a second plurality of holes, the second plurality of holes being configured to receive a portion of one or more of the second plurality of fingers to constrain the second bus bar assembly.

[0006] In some aspects, the technology described herein relates to a traction battery pack assembly, further comprising: a cell stack, the first bus bar assembly and the first locking bar disposed along a first side of the cell stack, and the second bus bar assembly and the second locking bar disposed along an opposite second side of the cell stack.

[0007] In some aspects, the technology described herein relates to a traction battery pack assembly in which the first bus bar assembly is pivotally coupled to a first side of a cover spanning the cell stack, and the second bus bar assembly is pivotally coupled to an opposing second side of the cover.

[0008] In some aspects, the technology described herein relates to a traction battery pack assembly wherein each of the apertures within the plurality of apertures receives one of the fingers within the plurality of fingers.

[0009] In some aspects, the technology described herein relates to a traction battery pack assembly wherein the plurality of fingers are tapered.

[0010] In some aspects, the technology described herein relates to a traction battery pack assembly wherein the plurality of apertures is a plurality of pockets and the locking bar is circumferentially disposed completely around the portion of one or more of the fingers within the plurality of fingers to constrain the bus bar assembly.

[0011] In some aspects, the technology described herein relates to a traction battery pack assembly, further comprising: a cell stack having a plurality of battery cells arranged along an axis, the plurality of battery cells positioned between compression structures located at opposite axial ends of the cell stack, the bus bar assembly and the locking bar arranged along a side of the cell stack, the locking bar clamped to the compression structure.

[0012] In some aspects, the technology described herein relates to a traction battery pack assembly wherein the compression structure is a cross member.

[0013] In some aspects, the technology described herein relates to a traction battery pack assembly, further comprising: a cell stack having a plurality of battery cells with tab terminals, wherein the frame includes a plurality of slots within which the tab terminals are received.

[0014] In some aspects, the technology described herein relates to a method of assembling a battery pack, comprising: securing a locking bar relative to a cell stack; moving a bus bar assembly into a mounted position relative to the cell stack, the bus bar assembly comprising a plurality of bus bars mounted to a frame; and inserting a plurality of fingers of the frame into a plurality of holes of the locking bar during the movement.

[0015] In some aspects, the technology described herein relates to a method that also includes dampening vibration of the plurality of fingers using the locking bar.

[0016] In some aspects, the technology described herein relates to a method further comprising: constraining movement of the plurality of fingers using the locking bar.

[0017] In some aspects, the technology described herein relates to a method further comprising: clamping the locking bar to at least one compression structure when securing the locking bar.

[0018] In some aspects, the technology described herein relates to a method further comprising securing a plurality of tab terminals of the cell stack to the plurality of bus bars.

[0019] In some aspects, the technology described herein relates to a method wherein the securing comprises welding the plurality of tab terminals to at least one of the bus bars within the plurality of bus bars.

[0020] In some aspects, the technology described herein relates to a method in which the bus bar assembly is pivotally secured to a cover spanning a cell stack when the plurality of fingers are received within the plurality of apertures of the locking bar.

[0021] In some aspects, the technology described herein relates to a method wherein the bus bar assembly is a first bus bar assembly disposed along a first side of the battery cell stack, and the method further comprises: disposing a second bus bar assembly along an opposite second side of the battery cell stack, the second bus bar being pivotally secured to the cover.

[0022] The embodiments, examples and alternatives of the preceding paragraphs, claims or following description and drawings, including any of their various aspects or corresponding individual features, may be taken independently or in any combination. Features described in conjunction with one embodiment apply to all embodiments, unless such features are incompatible. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The various features and advantages of the disclosed examples will become apparent to those skilled in the art based on the detailed description. The drawings accompanying the detailed description can be briefly described as follows:

[0024] Figure 1 A side view of an electrified vehicle is shown.

[0025] Figure 2 An exemplary embodiment according to the present disclosure is shown Figure 2 An enlarged perspective view of a battery pack for an electrified vehicle.

[0026] Figure 3 Shown Figure 2 The battery cells of the battery pack.

[0027] Figure 4 Shown Figure 2 the locking bar of the battery pack.

[0028] Figure 5 A portion of a busbar module is shown in an installed position, wherein the fingers of the busbar module are Figure 4 Lock bar constraint.

[0029] Figure 6 Shown in Figure 5 A cross-sectional view taken along line 6–6 in FIG. DETAILED DESCRIPTION

[0030] This disclosure details example locking bars that can be used to restrain a bus bar module within a battery pack and dampen vibrations. The locking bars can help support the bus bar module when tab terminals are secured to its bus bars.

[0031] refer to Figure 1 , the electrified vehicle 10 includes a battery pack 14, an electric motor 18, and wheels 22. The battery pack 14 powers the electric motor 18, which converts the electricity into mechanical power to drive the wheels 22. Therefore, the battery pack 14 is a traction battery pack.

[0032] In the exemplary embodiment, the battery pack 14 is secured to an underbody 26 of the electrified vehicle 10. In other examples, the battery pack 14 may be located elsewhere on the electrified vehicle 10.

[0033] The electrified vehicle 10 is a pure electric vehicle. In other examples, the electrified vehicle 10 is a hybrid electric vehicle that selectively uses torque provided by an internal combustion engine (as an alternative to or in addition to an electric motor) to drive the wheels. In general, the electrified vehicle 10 can be any type of vehicle having a battery pack.

[0034] Now refer to Figure 2 and Figure 3 , the battery pack 14 includes a plurality of cell stacks 30 held within a housing assembly 34. In the exemplary embodiment, the housing assembly 34 includes a housing cover 38 and a housing tray 42. The housing cover 38 can be secured to the housing tray 42 to provide an interior area 44 that accommodates the cell stacks 30. The housing cover 38 can be secured to the housing tray 42 using, for example, mechanical fasteners (not shown).

[0035] Each of the stacks 30 includes, among other things, a plurality of battery cells 50 (or simply "cells") stacked side-by-side relative to one another along a respective stack axis A. In this example, the axis A of the stack 30 extends longitudinally from a forward end to a rearward end of the vehicle 10.

[0036] The battery cells 50 store and supply electrical power. Although a specific number of cell stacks 30 and cells 50 are shown in the various figures of this disclosure, the battery pack 14 may include any number of cell stacks 30 , each having any number of individual cells 50 .

[0037] In one embodiment, the battery cell 50 is a lithium-ion pouch cell. However, battery cells having other geometries (cylindrical, prismatic, etc.), other chemistries (nickel-metal hydride, lead acid, etc.), or both may alternatively be utilized within the scope of the present disclosure.

[0038] Now refer to Figures 4 to 6 And continue to refer to Figures 1 to 3 , each of the cell stacks 30 is sandwiched along its axis A between compression structures 52, which are provided at opposite axial ends of the cell stack 30. In this example, the compression structure 52 is a cross member within the housing tray 42. In another example, the compression structure 52 is part of the housing assembly 34, such as the housing cover 38 or the housing tray 42. In yet other examples, the compression structure 52 is an end plate. The compression structure 52 is compressive because it maintains the cell stack 30 in a compressed state along the corresponding axis A.

[0039] Each of the example battery cells 50 includes a pair of tab terminals 54 extending from a housing 56. Within a given one of the cell stacks 30, the individual battery cells 50 can be electrically connected together. To provide these electrical connections, the tab terminals 54 of the battery cells 50 can be connected to the tab terminals 54 of other battery cells 50.

[0040] In this example, an interconnector assembly 62 is associated with each of the cell stacks 30. Each interconnector assembly 62 includes a cover 66 and a pair of bus bar assemblies 70. One of the bus bar assemblies 70 is pivotally coupled to each side of the cover 66. When the interconnector assembly 62 is installed, the cover 66 of the interconnector assembly 62 spans the corresponding cell stack 30, with the bus bar assemblies 70 disposed along opposite sides of the corresponding cell stack 30.

[0041] The bus bar assemblies 70 each include a frame 74 and a plurality of bus bars 78 mounted to the frame 74. In this example, the bus bars 78 are mounted to the frame 74 using heat stakes.

[0042] The frame 74 includes a plurality of fingers 82. Slots 86 are positioned between the fingers 82. When the interconnect assembly 62 is moved to the installed position, the tab terminal 54 is received in one of the slots 86. The tab terminal 54 is then folded over and secured to one of the bus bars 78. In this example, the tab terminal 54 is welded to the bus bar 78 after being folded over.

[0043] The battery pack 14 includes a locking bar 90 disposed along each side of the cell stack 30. The locking bar 90 includes a plurality of apertures 94. In this example, the apertures 94 are recessed pockets that open vertically upward and do not open to the sides of the locking bar 90. In another example, the apertures 94 may be slots that open to one or more sides of the locking bar 90. For the purposes of this disclosure, vertical and horizontal are used with reference to the ground and the general orientation of the vehicle 10 and battery pack 14 during operation.

[0044] As the bus bar assembly 70 is moved to a seated position in which the tab terminals 54 are received within the slots 86 of the frame 74, a portion of each of the fingers 82 is inserted into one of the holes 94. The movement of the fingers 82 is restrained when a portion of the fingers 82 is received within each of the holes 94. The fingers 82 are tapered to facilitate insertion into the holes 94.

[0045] In this example, locking bar 90 constrains at least horizontal movement and vibration of finger 82. Each of holes 94 receives a portion of one of fingers 82—here, the tip of finger 82. In another example, hole 94 may receive portions of more than one of fingers 82.

[0046] When the fingers 82 are received within the apertures 94 , the locking bar 90 is completely circumferentially disposed around a portion of one or more of the fingers 82 to restrain the bus bar assembly 70 .

[0047] Constraining the movement of the fingers 82 can help dampen vibrations of the fingers 82 when, for example, the vehicle 10 is driven. Constraining the movement of the fingers 82 can also help support the fingers 82 when the tab terminals 54 are welded to the bus bar 78.

[0048] In this example, the locking strip 90 is clamped into the compression structure 52 to secure the locking strip 90. In this example, protrusions 96 at opposite ends of the locking strip 90 are received within holes 98 of the compression structure 52 to clamp the locking strip 90 into the compression structure 52. The locking strip 90 may alternatively or additionally be mechanically fastened to the housing tray 42 using threaded fasteners, such as bolts.

[0049] The foregoing description is illustrative rather than restrictive in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art, and such variations and modifications do not necessarily depart from the essence of the present disclosure. Therefore, the scope of protection afforded to the present disclosure should be determined solely by studying the appended claims.

Claims

1. A traction battery pack assembly, comprising: a bus bar assembly having a frame and at least one bus bar, the frame including a plurality of fingers; as well as A locking bar has a plurality of apertures each configured to receive a portion of one or more of the fingers to restrain the bus bar assembly.

2. The traction battery pack assembly of claim 1, wherein the bus bar assembly is pivotally coupled to a cover spanning the battery cell stack.

3. The traction battery pack assembly of claim 2, wherein the locking bar is a first locking bar and the plurality of holes is a first plurality of holes, the bus bar assembly is a first bus bar assembly pivotally coupled to the first side of the cover, the frame is a first frame, the plurality of fingers is a first plurality of fingers, and the traction battery pack assembly further comprises: The second bus bar assembly and the second locking bar, The second bus bar assembly has a second frame with a second plurality of fingers and at least one second bus bar, the second locking bar having a second plurality of holes configured to receive a portion of one or more of the second plurality of fingers to constrain the second bus bar assembly, and optionally, The traction battery pack assembly further includes a cell stack, the first bus bar assembly and the first locking bar disposed along a first side of the cell stack, and the second bus bar assembly and the second locking bar disposed along an opposite second side of the cell stack.

4. The traction battery pack assembly of claim 3, wherein the first bus bar assembly is pivotally coupled to a first side of a cover spanning the battery cell stack, and the second bus bar assembly is pivotally coupled to an opposite second side of the cover. 5 . The traction battery pack assembly of claim 1 , wherein each of said apertures within said plurality of apertures receives one of said fingers within said plurality of fingers.

6. The traction battery pack assembly of claim 1, wherein the plurality of fingers are tapered.

7. The traction battery pack assembly of claim 1 , wherein the plurality of apertures are a plurality of pockets, and wherein the locking bar is circumferentially disposed completely around the portion of one or more of the fingers within the plurality of fingers to constrain the bus bar assembly.

8. The traction battery pack assembly according to claim 1, further comprising: A cell stack having a plurality of battery cells arranged along an axis, the plurality of battery cells being positioned between compression structures at opposite axial ends of the cell stack, the bus bar assembly and the locking bar being arranged along a side of the cell stack, the locking bar being clamped to the compression structure, and optionally, wherein the compression structure is a cross member.

9. The traction battery pack assembly according to claim 1, further comprising: A cell stack having a plurality of battery cells with tab terminals, wherein the frame includes a plurality of slots into which the tab terminals are received.

10. A method for assembling a battery pack, comprising: securing the locking bar relative to the cell stack; moving a bus bar assembly into a mounted position relative to the battery cell stack, the bus bar assembly comprising a plurality of bus bars mounted to a frame; as well as During the movement, the plurality of fingers of the frame are inserted into the plurality of holes of the locking bar.

11. The method for assembling a battery pack according to claim 10, further comprising: The locking strip is used to dampen vibrations of the plurality of fingers.

12. The method for assembling a battery pack according to claim 10, further comprising: The locking bar is used to constrain movement of the plurality of fingers.

13. The method for assembling a battery pack according to claim 10, further comprising: When securing the locking strip, the locking strip is clamped to at least one compression structure.

14. The method for assembling a battery pack according to claim 10, further comprising: A plurality of tab terminals of the cell stack are secured to the plurality of bus bars, and optionally, wherein the securing comprises welding the plurality of tab terminals to at least one of the bus bars within the plurality of bus bars.

15. The method of assembling a battery pack according to claim 10, wherein the bus bar assembly is pivotally secured to a cover spanning a cell stack when the plurality of fingers are received within the plurality of holes of the locking bar, and optionally, wherein the bus bar assembly is a first bus bar assembly disposed along a first side of the cell stack, and the method further comprising: A second bus bar assembly is provided along an opposite second side of the cell stack, the second bus bar being pivotally secured to the cover.

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