CN116805719A - Traction battery pack assembly method - Google Patents

Abstract

The present disclosure provides a "traction battery pack assembly method". A method of battery pack assembly includes holding a cell stack with a compressor. The compressor is engaged with a first load plate at a first end of the cell stack and with a second load plate at an opposite second end of the cell stack during the holding. The method further comprises the steps of: aligning the cell stack relative to a housing structure while the compressor holds the cell stack; inserting the cell stack into a cell receiving opening of a housing structure; and disengaging the compressor from the first load plate and the second load plate.

Description

Traction battery pack assembly method

Cross Reference to Related Applications

The present application claims priority from U.S. provisional application No. 63/322766, filed 3/23 at 2022, and which is 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 to move a cell stack 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 battery pack assembly method comprising: holding a cell stack with a compressor, the compressor being engaged with a first load plate at a first end of the cell stack and with a second load plate at an opposite second end of the cell stack during the holding; aligning the cell stack relative to a housing structure while the compressor holds the cell stack; and inserting the cell stack into a cell receiving opening of a housing structure; and disengaging the compressor from the first load plate and the second load plate.

In some aspects, the techniques described herein relate to a method wherein the detaching is after the inserting.

In some aspects, the technology described herein relates to a method wherein the compressor is engaged with the first load plate by at least one first pin received within a cell stack slot of the first load plate and is engaged with the second load plate by at least one second pin received within a cell stack slot of the second load plate.

In some aspects, the technology described herein relates to a method wherein the at least one first pin comprises at least two first pins, each first pin received within a respective slot of the first load plate, wherein the at least one second pin comprises at least two second pins, each second pin received within a respective slot of the second load plate.

In some aspects, the technology described herein relates to a method wherein the housing structure includes at least one first clearance groove that receives the at least one first pin during the disengaging and at least one second clearance groove that receives the at least one second pin during the disengaging.

In some aspects, the techniques described herein relate to a method that further includes disengaging by moving the at least one first pin and the at least one second pin away from each other into the respective at least one first clearance groove or at least one second clearance groove.

In some aspects, the techniques described herein relate to a method further comprising removing the at least one first pin from the at least one first clearance groove, removing the at least one second pin from the at least one second clearance groove, and then introducing an adhesive into the at least one first clearance groove and into the at least one second clearance groove.

In some aspects, the technology described herein relates to a method wherein the cell stack is compressed along a cell stack axis during the holding.

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

In some aspects, the techniques described herein relate to a method further comprising compressing the cell stack with the housing structure after the inserting.

In some aspects, the technology described herein relates to a method wherein the housing structure circumferentially surrounds the cell stack after the inserting.

In some aspects, the technology described herein relates to a method wherein the housing structure is a housing ring.

In some aspects, the technology described herein relates to a method wherein the compressor is a 7-axis compression device.

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 housing structure holding the cell stack within a cell receiving opening and compressing the cell stack along the respective cell stack axis; and at least one load plate of the cell stack, the at least one load plate having at least one cell stack slot that receives a pin of a compressor when the cell stack is loaded into the cell receiving opening.

In some aspects, the technology described herein relates to a traction battery pack assembly that further includes an adhesive within the at least one cell stack slot.

In some aspects, the technology described herein relates to a traction battery pack assembly, the housing structure including a clearance groove configured to receive a pin of the compressor when the pin is removed from the housing structure.

In some aspects, the technology described herein relates to a traction battery pack assembly wherein the load plate has a chamfered leading edge.

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 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 are in direct contact with the housing structure.

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 of the motorized vehicle of fig. 1.

Fig. 3 shows a set of cells compressed to provide a cell stack for the traction battery pack of fig. 2.

Fig. 4 shows the cell stack of fig. 3 compressed and provided with a cell stack.

Fig. 5 shows a perspective view of a compressor engaged with the cell stack of fig. 4 and loaded into the housing structure of the traction battery pack.

Fig. 6 shows a close-up view of the area of fig. 5 showing the compressor engaged with the cell stack.

Fig. 7 shows the region of fig. 6 after the compressor has been disengaged from the cell stack.

Fig. 8 illustrates a close-up perspective view of a compressor loading the cell stack of fig. 8 into a housing structure according to another exemplary embodiment of the present disclosure.

Fig. 9 shows another close-up view of the embodiment of fig. 8 with the cell stack removed to show the clearance recess of the housing.

Detailed Description

The present disclosure details an exemplary traction battery pack assembly having a housing providing an interior region. The cells and electronics modules may be held within the interior region along with other components. The electrical core may be used to power a motor.

In particular, the present disclosure details exemplary systems and methods related to assembling a traction battery pack assembly.

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 14 may be a relatively high voltage battery.

In the exemplary embodiment, traction battery pack 14 is secured to underbody 26 of electric vehicle 10. In other examples, traction battery pack 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 complement to an electric motor) to drive the 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 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 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 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 cells 30, and the cell matrix 50 includes four cell stacks 46.

Although a particular number of 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 cells 30 and cell stacks 46. In some examples, the use of a uniform number of 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 battery cell. However, cells having other geometries (cylindrical, pouch, 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 side walls 56 are arranged relative to one another to provide a cell receiving opening 60. The side walls 56 may be extruded, roll formed, cast, molded structures or other structures joined together by, for example, welding, fastening, or bonding. The side walls 56 may extend vertically upward from the housing floor 42.

The housing cover 38 may be secured to the vertical upper side 62 of the housing ring 40 when the traction battery pack assembly 14 is assembled. The interface between the housing cover 38 and the housing ring 40 extends circumferentially continuously around the interior region 44. For example, mechanical fasteners or welds may be used to secure the housing cover 38 and the housing ring 40. For purposes of this disclosure, vertical is a reference to the ground and the general direction of the electrified vehicle 10 during operation.

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

When the cell matrix 50 is inserted into the cell receiving opening 60 of the housing ring 40, 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 opening 60.

Traction battery pack assembly 14 may be considered a cell-pack battery assembly. Unlike conventional traction battery pack battery assemblies, the cell-battery pack battery assembly incorporates a battery cell or other energy storage device into the housing assembly 34, with the battery cells not arranged in an array or module. The housing assembly 34 applies a compressive force to the cells. Thus, the cell-to-cell pack assembly may eliminate most, if not all, of the array support structures (e.g., array frames, spacers, rails, end plates, ties, etc.) used in conventional battery arrays for grouping and retaining 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 openings of the housing ring 40. To insert the example cell stack 46, the cell stack 46 is moved into position in the cell receiving opening 60 while being compressed. Spacers may be used to maintain the spacing between the different cell stacks 46.

An exemplary method of assembling traction battery pack assembly 14 will now be explained in connection with fig. 3-8.

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

In this example, within the cell stack 46, a spacer 72 is disposed between each of the cells 30 along the cell stack axis a. The spacer 72 may include a frame portion 74 that holds a compressible material 76. When installed with traction battery pack assembly 14, compressible material 76 may compress to allow some of the cells of cells 30 to expand. Compressible material 76 may be foam.

The opposite axial end of each of the cell stacks 46 includes a load plate 80. Load plate 80 includes a frame portion 82 that holds a compressible material 84. Compressible material 76 may be foam. The compressible material 84 may compress to allow some of the cells 30 to expand. The load plates 80 also each include at least one cell stack slot 86 that will be utilized when the cell stack 46 is assembled into the housing ring 40. In some examples, the load plate 80 omits the compressible material 84.

Next, as shown in fig. 5, the cell stack 46 is grasped by a compressor 90, which maintains the compression of the cell stack 46. In some examples, the compressor 90 is responsible for compressing the cell stack 30 to provide the cell stack 46. In other examples, for example, the compressor 90 grabs the cell stack 46 that has been compressed by the compression fixture.

The exemplary compressor 90 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 92 and a pair of second pins 96. Although two first pins 92 and two second pins 96 are shown in this example, other examples may include one first pin and one second pin, or more than two first pins and second pins.

The compressor 90 may move the first pin 92 and the second pin 96 back and forth relative to each other along the axis D to selectively increase or decrease the distance between the first pin 92 and the second pin 96.

To retain the cell stack 46, the first pin 92 and the second pin 96 are each placed beside a respective one of the load plates 80. The first pin 92 and the second pin 96 are then moved closer together to engage a corresponding one of the load plates 80. The first pins 92 each move into one of the cell stack slots 86 on one of the load plates 80. The second pins 96 each move into one of the cell stack slots 86 on the other of the load plates 80. Moving the first pin 92 and the second pin 96 into the cell stack slot 86 engages the compressor 90 with the load plate 80. Positioning the first pin 92 and the second pin 96 within the cell stack slot 86 also facilitates repeatable alignment of the cell stack 46 relative to the compressor 90.

The compressor 90 is then moved to align the cell stack 46 for insertion into the cell receiving opening 60 of the tray 54. Once aligned, the compressor 90 is moved to insert the cell stack 46 into the cell receiving opening 60 of the tray 54 until the cell stack 46 is in the position of fig. 6. The cell stack 46 is inserted into the tray 54 in a direction perpendicular to the axis a. The leading edge 98 of the load plate 80 may be angled or chamfered to aid in guiding the core stack 46 through the compressor 90 into the core receiving opening 60.

After the cell stack 46 is positioned within the tray 54, the first pin 92 and the second pin 96 are then moved away from each other. This disengages the compressor 90 from the cell stack 46. Compression of the cell stack 46 is then maintained by the walls 56 of the tray 54. The example load plate 80 is in direct contact with the wall 56 of the tray 54 when installed.

With the first pin 92 and the second pin 96 disengaged from the cell stack 46, the compressor 90 may remove the first pin 92 and the second pin 96 from the respective cell stack slots 86, as shown in fig. 7. The compressor 90 may then be moved to engage the load plate of another cell stack 46 and load that cell stack 46 into the housing tray 54.

In some examples, the adhesive may be introduced by injection into the cell stack slots 86 after disengagement from the compressor 90. The adhesive may help maintain the position of the cell stack 46 within the tray 54.

After the cell stack 46 and other components are positioned within the tray 54, the cover 38 may be secured to the tray 54. Traction battery pack assembly 14 may then be installed into electrically powered vehicle 10 of fig. 1.

Referring to fig. 8 and 9, another exemplary embodiment may include a tray 54a having clearance grooves 100 in the side walls 56. In some examples, the clearance groove 100 may at least partially receive the first pin 92 or the second pin 96 when the compressor 90 is inserted into the cell stack 46. This may be used as a locator feature to help align the cell stack 46 with the tray 54 during insertion.

The clearance groove 100 also provides clearance for the first pin 92 or the second pin 96 to move outwardly from the cell stack 46 when the compressor 90 is disengaged from the cell stack 46. Like the cell stack slots 86, adhesive may be introduced into the clearance groove 100 after disengaging the compressor 90 from the cell stack 46 and removing the first pin 92 and the second pin 96 from the tray 54.

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 (15)

1. A battery pack assembly method, comprising:

holding a cell stack with a compressor, the compressor being engaged with a first load plate at a first end of the cell stack and with a second load plate at an opposite second end of the cell stack during the holding;

aligning the cell stack relative to a housing structure while the compressor holds the cell stack; and

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

the compressor is disengaged from the first load plate and the second load plate.

2. The method of claim 1, wherein the disengaging is after the inserting.

3. The method of claim 1, wherein the compressor is engaged with the first load plate by at least one first pin received in a cell stack slot of the first load plate and with the second load plate by at least one second pin received in a cell stack slot of the second load plate, and optionally wherein the at least one first pin comprises at least two first pins, each first pin received in a respective slot of the first load plate, wherein the at least one second pin comprises at least two second pins, each second pin received in a respective slot of the second load plate.

4. The method of claim 3, wherein the housing structure includes at least one first clearance groove that receives the at least one first pin during the disengaging and at least one second clearance groove that receives the at least one second pin during the disengaging, and optionally wherein the method further comprises disengaging by moving the at least one first pin and the at least one second pin away from each other into the respective at least one first clearance groove or at least one second clearance groove.

5. The method of claim 4, further comprising removing the at least one first pin from the at least one first clearance groove, removing the at least one second pin from the at least one second clearance groove, and then introducing an adhesive into the at least one first clearance groove and into the at least one second clearance groove.

6. The method of claim 1, wherein the cell stack is compressed along a cell stack axis during the holding, and optionally wherein the inserting moves the first cell stack relative to the housing structure in a direction perpendicular to the cell stack axis.

7. The method of claim 1, further comprising compressing the cell stack with the housing structure after the inserting, and optionally wherein the housing structure circumferentially surrounds the cell stack after the inserting.

8. The method of claim 7, wherein the housing structure is a housing ring.

9. The method of claim 1, wherein the compressor is a 7-axis compression device.

10. A traction battery pack assembly, comprising:

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

a housing structure holding the cell stack within a cell receiving opening and compressing the cell stack along the respective cell stack axis; and

at least one load plate of the cell stack having at least one cell stack slot that receives a pin of a compressor when the cell stack is loaded into the cell receiving opening.

11. The traction battery pack assembly of claim 10, further comprising an adhesive within the at least one cell stack slot.

12. The traction battery pack assembly of claim 10, the housing structure including a clearance groove configured to receive a pin of the compressor when the pin is removed from the housing structure.

13. The traction battery pack assembly of claim 10 wherein the load plate has a chamfered leading edge.

14. The traction battery pack assembly of claim 10 wherein the housing structure is a housing tray.

15. The traction battery pack assembly of claim 10, 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, and optionally wherein the first load plate and the second load plate are in direct contact with the housing structure.