CN116845455A

CN116845455A - Traction battery pack housing and traction battery pack assembly method

Info

Publication number: CN116845455A
Application number: CN202310243436.2A
Authority: CN
Inventors: 贾森·C·马尔卡思; 弗拉基米尔·弗拉基米罗维奇·博加丘克; 罗伯特·赖纳斯; K·赛勒
Original assignee: Ford Global Technologies LLC
Current assignee: Ford Global Technologies LLC
Priority date: 2022-03-23
Filing date: 2023-03-14
Publication date: 2023-10-03

Abstract

The present disclosure provides a traction battery pack case and a traction battery pack assembly method. A traction battery pack assembly includes a cell stack disposed along a cell stack axis. The metal plate housing structure holds the cell stack within the cell receiving area and compresses the cell stack along the cell stack axis. A battery pack assembly method includes: forming a sheet metal blank into a shell structure having a cell receiving region; inserting the cell stack into a cell receiving region of the housing structure; and after insertion, compressing the cell stack with the housing structure.

Description

Traction battery pack housing and traction battery pack assembly method

Cross Reference to Related Applications

The present application claims priority from U.S. provisional application No. 63/322766, filed on day 23 of 3.2022, incorporated herein by reference.

Technical Field

The present disclosure relates generally to a method of assembling a traction battery pack, and more particularly to how a cell stack moves into the housing of the battery pack.

Background

Motorized vehicles differ from conventional motor vehicles in that motorized vehicles include a drive train having one or more electric machines. Alternatively or in addition to the internal combustion engine, the electric machine may drive an electrically powered vehicle. The traction battery pack assembly may power the motor. A traction battery pack assembly of an motorized vehicle may include a battery cell stack.

Disclosure of Invention

In some aspects, the technology described herein relates to a traction battery pack assembly comprising: the battery cell stack is arranged along the axis of the battery cell stack; a sheet metal housing structure that holds the cell stack within a cell receiving area and compresses the cell stack along the respective cell stack axis.

In some aspects, the technology described herein relates to a traction battery pack assembly, wherein the sheet metal housing structure is a stamped sheet metal housing structure.

In some aspects, the technology described herein relates to a traction battery pack assembly, wherein the housing structure is a housing tray.

In some aspects, the technology described herein relates to a traction battery pack assembly further comprising at least one load plate of the cell stack, the at least one load plate having a chamfered leading edge.

In some aspects, the technology described herein relates to a traction battery pack assembly wherein the at least one load plate includes a first load plate at a first axial end of the cell stack and a second load plate at an opposite second axial end of the cell stack.

In some aspects, the technology described herein relates to a traction battery pack assembly wherein the first load plate and the second load plate directly contact the housing structure.

In some aspects, the technology described herein relates to a traction battery pack assembly wherein the sheet metal housing structure circumferentially surrounds the cell stack.

In some aspects, the technology described herein relates to a traction battery pack assembly, wherein the metal plate is a metal alloy.

In some aspects, the technology described herein relates to a traction battery pack assembly further comprising at least one wedge disposed between a wall of the sheet metal housing structure and the cell stack.

In some aspects, the technology described herein relates to a traction battery pack assembly, the battery cell stack being a first battery cell stack, and the traction battery pack assembly further comprising at least one second battery cell stack retained within a battery cell receiving area of the sheet metal housing structure and compressed along a respective battery cell stack axis. In some aspects, the technology described herein relates to a method further comprising inserting the cell stack into the cell receiving area using a compressor.

In some aspects, the technology described herein relates to a battery pack assembly method comprising: forming a sheet metal blank into a shell structure having a cell receiving region; inserting a cell stack into a cell receiving region of the housing structure; and compressing the cell stack with the housing structure after the inserting.

In some aspects, the techniques described herein relate to a method of compressing the cell stack with the compressor during the inserting.

In some aspects, the technology described herein relates to a method, wherein the compressing comprises compressing the cell stack along a cell stack axis.

In some aspects, the technology described herein relates to a method wherein the inserting moves the cell stack relative to the housing structure in a direction perpendicular to the cell stack axis.

In some aspects, the technology described herein relates to a method further comprising filling a gap between the housing structure and the cell stack with at least one wedge.

In some aspects, the technology described herein relates to a method further comprising compressing the cell stack with at least one wedge sandwiched between the housing structure and the cell stack.

In some aspects, the techniques described herein relate to a method wherein the forming is stamping.

In some aspects, the technology described herein relates to a method wherein the metal plate is a metal alloy.

Embodiments, examples, and alternatives of the foregoing paragraphs, claims, or the following description and drawings, including any of their various aspects or respective individual features, may be employed separately or in any combination. Features described in connection with one embodiment are applicable to all embodiments unless such features are incompatible.

Drawings

Various features and advantages of the disclosed examples will become apparent to those skilled in the art from the detailed description. The drawings that accompany the detailed description can be briefly described as follows:

fig. 1 shows a side view of an electrically powered vehicle.

Fig. 2 shows a partially expanded view of a traction battery pack from the motorized vehicle of fig. 1.

Fig. 3 shows the press and sheet metal blank prior to the forming operation.

Fig. 4 shows the press and sheet metal blank after the forming operation.

Fig. 5 shows a close-up view of the area 5 in fig. 2.

Fig. 6 shows a cross-sectional view taken along line 6-6 in fig. 5.

Fig. 7 shows a cell stack compressed to provide a cell stack for the traction battery pack of fig. 2.

Fig. 8 shows the cell stack of fig. 7 compressed and provided with a cell stack.

Fig. 9 shows a perspective view of a compressor engaged with the cell stack of fig. 8 for inserting the cell stack into the housing structure of a traction battery pack.

Fig. 10 shows a perspective view of a pusher of a compressor that inserts the cell stack of fig. 8 into a housing structure of a traction battery pack.

Detailed Description

The present disclosure details an exemplary traction battery pack assembly having a housing that provides an interior region. The battery cells and the electronic module may be held within the interior region along with other components. The battery cells may be used to power a motor.

In particular, the present disclosure details exemplary assemblies and methods involving compressing a sheet metal housing of a battery cell of a battery pack.

Referring to fig. 1, an electrically powered vehicle 10 includes a traction battery pack assembly 14, an electric machine 18, and wheels 22. Traction battery pack assembly 14 powers electric machine 18, which may convert electrical power to mechanical power to drive wheels 22. Traction battery pack assembly 14 may be a relatively high voltage battery.

In the exemplary embodiment, traction battery pack assembly 14 is secured to underbody 26 of electric vehicle 10. In other examples, traction battery pack assembly 14 may be located elsewhere in electric vehicle 10.

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

Referring now to fig. 2, the traction battery pack assembly 14 includes a plurality of battery cells 30 held within a housing assembly 34. In the exemplary embodiment, housing assembly 34 includes a variety of housing structures. Specifically, the example housing assembly 34 includes a housing cover 38, a housing ring 40, and a housing floor 42. The housing cover 38, housing ring 40, and housing base plate 42 are secured together to provide an interior region 44 that accommodates the plurality of battery cells 30.

A plurality of battery cells (or simply "cells") 30 are used to supply power to the various components of the motorized vehicle 10. The battery cells 30 are stacked side-by-side with respect to one another to construct one of a plurality of cell stacks 46 that are positioned side-by-side to provide a cell matrix 50. In this example, each cell stack 46 includes eight individual battery cells 30, and the cell matrix 50 includes four cell stacks 46.

Although a particular number of battery cells 30 and cell stacks 46 are shown in various embodiments of the present disclosure, the traction battery pack assembly 14 may include any number of battery cells 30 and cell stacks 46. In some examples, the use of a uniform number of battery cells 30 and a uniform number of cell stacks 46 may help support an efficient electrical bus arrangement. In other words, the present disclosure is not limited to the particular configuration of the cells 30 shown in fig. 2.

In an embodiment, the battery cell 30 is a prismatic lithium ion cell. However, battery cells having other geometries (cylindrical, soft pack, etc.) and/or chemistries (nickel-metal hydride, lead acid, etc.) may alternatively be utilized within the scope of the present disclosure.

In this example, the housing ring 40 and the housing floor 42 are part of a housing tray 54. Specifically, the housing ring 40 is provided by a plurality of side walls 56 of the housing tray 54. The sidewalls 56 are arranged relative to one another to provide a cell receiving region 60. The side walls 56 may extend vertically upward from the housing floor 42.

The housing tray 54 is a sheet metal housing structure. As shown in fig. 3, the shell tray 54 may be formed by stamping a sheet metal blank 200 in a press 204. The sheet metal blank 200 may be a metal or metal alloy.

To shape the housing tray 54, the tool 208 punches the blank 200 into the die cavity 212 of the die 216. The tool 208 is then removed, leaving the housing tray 54 within the mold cavity 212, as shown in FIG. 4.

The side walls 56 of the tray 54 are at an angle a to the vertical axis. Angle a is the draft angle that helps facilitate removal of tray 54 from mold 216.

Referring now to fig. 2, 5 and 6, a plurality of wedges 64 are used within the tray 54. The wedge 64 is sandwiched between the side wall 56 and the cell stack 46. In this example, one of the wedges 64 is disposed beside a first axial end of the cell stack 46 and the other of the wedges 64 is disposed beside an opposite second axial end of the cell stack 46. The wedge 64 fills the gap between the cell stack 46 and the sidewall 56, thereby compensating for the angle a.

Specifically, the inner side 68 of the wedge 64 interfaces directly with the cell stack 46, and in this example, is disposed along a vertical plane. The outer side 70 of the wedge 64 includes an area that is angled with respect to the vertical plane. This area directly contacts the side wall 56 of the tray 54.

The wedge 64 may be compressed. For example, the wedge 64 may be secured to the tray 54 using bolts or welds. Wedge 64 has a wedge-shaped cross section.

In this example, the tray 54 also houses a pair of compression beams 72. The compression beam 72 may help maintain a desired distance between the wedges 64.

The housing cover 38 may be secured to the flange 74 of the tray 54 when the traction battery pack assembly 14 is assembled. The interface between the housing cover 38 and the flange 74 extends continuously circumferentially around the interior region 44. For example, mechanical fasteners or welds may be used to secure the housing cover 38 and flange 74. For purposes of this disclosure, vertical is the overall orientation of the reference ground and the motorized vehicle 10 during operation.

When the traction battery pack assembly 14 is assembled, the cell matrix 50 is positioned within the cell receiving area 60. The exemplary housing ring 40 includes one cell receiving area 60, but it should be understood that the present disclosure also extends to housing assemblies that provide more than one cell receiving area. The housing cover 38 may cover the cell matrix 50 within the cell receiving area 60 to enclose the cells 30 from substantially all sides.

When the cell matrix 50 is inserted into the cell receiving area 60 of the housing ring 40 provided by the side walls 56, the housing ring 40 compresses and retains the cell matrix 50. In this example, the side walls 56 of the housing ring 40 apply a force to the cell matrix 50 when the cell matrix 50 is positioned within the cell receiving region 60. The wedge 64 accommodates the cell receiving region 60 such that compressive forces from the side walls 56 are transferred to the cell stack 46 through the vertical interface.

Traction battery pack assembly 14 may be considered a cell-pack battery assembly. Unlike conventional traction battery pack battery assemblies, the battery cells or other energy storage devices are incorporated into the housing assembly 34 without the cells being arranged in an array or module. The housing assembly 34 applies a compressive force to the cells. Thus, the cell-to-battery pack cell assembly may eliminate most, if not all, of the array support structures (e.g., array frames, spacers, rails, walls, end plates, ties, etc.) used in conventional battery arrays for grouping and retaining the battery cells within the array/module.

The cell matrix 50 includes a plurality of individual cell stacks 46 that can be individually inserted into the cell receiving areas of the housing ring 40. To insert the example cell stack 46, the cell stack 46 is moved into position in the cell receiving region 60 when compressed. Spacers may be used to maintain the spacing between the different cell stacks 46.

An exemplary method of assembling the traction battery pack assembly 14 will now be explained in connection with fig. 7-10.

First, a set of cells 30 is compressed along cell stack axis a, as shown in fig. 7, to provide one of the cell stacks 46, as shown in fig. 8. The cells may be compressed using a compression fixture. For example, a pneumatic actuator may drive a compression clamp to compress the cells 30 along the cell stack axis a. In some examples, the compressive force exerted on the cells 30 may be 3 kilonewtons.

In this example, within the cell stack 46, a separator 80 is disposed between each of the cells 30 along the cell stack axis a. The baffle 80 may include a frame portion 82 that holds a compressible material 84. When installed with traction battery pack assembly 14, compressible material 84 may compress to allow some expansion of cells 30. The compressible material 84 may be foam.

The opposite axial end of each of the cell stacks 46 includes a load plate 88. Load plate 88 includes a frame portion 90 that holds a compressible material 92. The compressible material 92 may be foam. The compressible material 92 may compress to allow some expansion of the cells 30. In some examples, the load plate 88 omits the compressible material 92.

Next, as shown in fig. 9, the cell stack 46 is grasped by the compressor 94 and removed from the compression fixture. In this example, the compressor 94 maintains compression of the cell stack 46. In some examples, the compressor 94 is responsible for compressing the set of cells 30 to provide the cell stack 46. In other examples, as here, the compressor 94 grasps the cell stack 46 that has been compressed by the compression fixture.

The exemplary compressor 94 is a 7-axis device, but other types of compression and insertion machines may be used. The exemplary compressor includes a pair of first pins 96 and a pair of second pins 98. Although two first pins 96 and two second pins 98 are shown in this example, other examples may include one first pin and one second pin, or more than two first pins and two second pins.

The compressor 94 may move the first and second pins 96, 98 back and forth relative to one another along the axis D to selectively increase or decrease the distance between the first and second pins 96, 98.

To retain the cell stack 46, the first pin 96 and the second pin 98 are each placed beside a respective one of the load plates 88. The first pin 96 and the second pin 98 then move closer against respective ones of the load plates 88 to grasp the cell stack 46. The compressor 94 is then moved to align the cell stack 46 for insertion into the cell receiving area 60 of the tray 54, as shown in fig. 9.

Next, as shown in fig. 10, the pusher 100 of the compressor 94 is transitioned from the retracted position to the extended position. Extending the pusher 100 slides the cell stack 46 relative to the first pin 96 and the second pin 98 and pushes the cell stack 46 into the mounted position within the cell receiving area 60. The load plate 88 of the cell stack 46 slides relative to the first pin 96 and the second pin 98 when pushed by the pusher 100. In this example, the cell stack 46 is pushed and inserted into the cell receiving region 60 in a direction perpendicular to the axis a of the cell stack. The load plate 88 may include a chamfered leading edge 104 (fig. 8) that may contact the wedges 64 during insertion and assist in guiding the insertion of the core stack 46 into the core receiving region 60 between the wedges 64.

The remaining cell stacks 46 of the matrix 50 are mounted in a similar manner. After the cell stack 46 and other components (such as bus bars) are positioned within the housing tray 54, the housing cover 38 may be secured to the housing tray 54. The housing cover 38 may be secured using, for example, mechanical fasteners. Traction battery pack assembly 14 may then be installed into electrically powered vehicle 10 of fig. 1.

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. Accordingly, the scope of protection afforded the present disclosure can only be determined by studying the following claims.

Claims

1. A traction battery pack assembly, comprising:

the battery cell stack is arranged along the axis of the battery cell stack;

a sheet metal housing structure that holds the cell stack within a cell receiving area and compresses the cell stack along the cell stack axis.

2. The traction battery pack assembly of claim 1, wherein the sheet metal housing structure is a stamped sheet metal housing structure.

3. The traction battery pack assembly of claim 1, wherein the housing structure is a housing tray.

4. The traction battery pack assembly of claim 1, further comprising at least one load plate of the cell stack, the at least one load plate having a chamfered leading edge, and optionally wherein the at least one load plate comprises a first load plate at a first axial end of the cell stack and a second load plate at an opposite second axial end of the cell stack.

5. The traction battery pack assembly of claim 4, wherein the first load plate and the second load plate directly contact the housing structure.

6. The traction battery pack assembly of claim 1, wherein the sheet metal housing structure circumferentially surrounds the cell stack.

7. The traction battery pack assembly of claim 1, wherein the metal plate is a metal alloy.

8. The traction battery pack assembly of claim 1, further comprising at least one wedge disposed between a wall of the sheet metal housing structure and the cell stack.

9. The traction battery pack assembly of claim 1, wherein the cell stack is a first cell stack, and further comprising at least one second cell stack retained within the cell receiving area of the sheet metal housing structure and compressed along a respective cell stack axis.

10. A battery pack assembly method, comprising:

forming a sheet metal blank into a shell structure having a cell receiving region;

inserting a cell stack into the cell receiving region of the housing structure; and

after the inserting, the cell stack is compressed with the housing structure.

11. The method of claim 10, further comprising inserting the cell stack into the cell receiving area using a compressor, and optionally compressing the cell stack with the compressor during the inserting.

12. The method of claim 10, wherein the compressing comprises compressing the cell stack along a cell stack axis, and optionally wherein the inserting moves the cell stack relative to the housing structure in a direction perpendicular to the cell stack axis.

13. The method of claim 10, further comprising filling a gap between the housing structure and the cell stack with at least one wedge, and optionally, the method further comprises compressing the cell stack with the at least one wedge sandwiched between the housing structure and the cell stack.

14. The method of claim 10, wherein the forming is stamping.

15. The method of claim 10, wherein the metal plate is a metal alloy.