CN116805725A - Traction battery pack assembly method - Google Patents

Abstract

The present disclosure provides a "traction battery pack assembly method". A battery pack assembly method includes: engaging the housing structure with a manufacturing apparatus; changing the size of a cell receiving opening in the housing structure using the manufacturing apparatus; inserting at least one cell stack into the cell receiving opening; and disengaging the manufacturing apparatus from the housing structure.

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: engaging the housing structure with a manufacturing apparatus; changing the size of a cell receiving opening in the housing structure using the manufacturing apparatus; inserting at least one cell stack into the cell receiving opening; and disengaging the manufacturing apparatus from the housing structure.

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

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

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

In some aspects, the techniques described herein relate to a method wherein the altering increases the size of the cell receiving opening.

In some aspects, the techniques described herein relate to a method wherein the cell receiving opening is reduced in size in response to the disengaging.

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

In some aspects, the technology described herein relates to a method wherein the enclosure structure is an enclosure tray.

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

In some aspects, the technology described herein relates to a method wherein each cell stack is disposed along a respective cell stack axis, wherein the inserting moves the at least one 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 wherein the housing structure circumferentially surrounds the cell stack after the inserting.

In some aspects, the techniques described herein relate to a method that further includes compressing the at least one cell stack during the inserting.

In some aspects, the technology described herein relates to a method further comprising changing a size of the cell receiving opening by inserting at least one wedge portion into the cell receiving opening.

In some aspects, the techniques described herein relate to a method wherein the at least one wedge portion includes a wedge portion of a first pin and a wedge portion of a second pin, and the method further comprises moving the at least one cell stack into the cell receiving opening during the inserting from a position in which the first pin and the second pin hold the at least one cell stack.

In some aspects, the technology described herein relates to a traction battery pack assembly comprising: at least one cell stack; and a housing structure having a cell receiving opening sized to receive the at least one cell stack, the housing structure compressing the at least one cell stack.

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 housing structure is a metal or metal alloy.

In some aspects, the technology described herein relates to a traction battery pack assembly wherein the at least one cell stack includes a first cell stack having a plurality of individual cells disposed along an axis along which the housing structure compresses the plurality of individual cells of the at least one cell stack.

In some aspects, the technology described herein relates to a traction battery pack assembly wherein the cell receiving opening is within a housing ring provided by a plurality of sidewalls of a housing tray.

In some aspects, the technology described herein relates to a traction battery pack assembly wherein the housing structure circumferentially surrounds the at least one cell stack. 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 manufacturing apparatus engaged with the cell stack of fig. 4 just prior to insertion of the cell stack into the housing structure of the traction battery pack.

Fig. 6 shows a close-up cross-sectional view showing pins of a manufacturing apparatus holding a cell stack prior to insertion into a housing structure.

Fig. 7 shows a cross section of fig. 6 after inserting the wedge-shaped portion of the pin into the housing structure to change the size of the cell receiving opening of the housing structure.

Fig. 8 shows a perspective view of the pin of fig. 7 holding a cell stack and inserted into a housing structure.

Fig. 9 shows a view of the fabrication facility of fig. 8 after the pusher has been extended to move the cell stack into the housing structure.

Fig. 10 shows the view of fig. 9 after retrieving pins from the cell receiving openings and disengaging the manufacturing equipment from the cell stack.

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 and efficient electrical bus arrangements. 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 side wall 56 and the remainder of the housing are shown.

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 the general orientation of the reference ground and 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.

After 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 60 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. The cell stacks 46 each include a set of cells 30 disposed along an axis.

An exemplary method of assembling the traction battery pack assembly 14 will now be explained in connection with fig. 3-10. First, the cell stack 30 is compressed along the 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, the actuator may drive the 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.

Next, as shown in fig. 5, the cell stack 46 is engaged by a manufacturing apparatus 90 that can maintain a compressive load on the cell stack 46 when engaged with the cell stack 46. In this example, the manufacturing apparatus 90 is engaged with the cell stack 46 that has been compressed, for example, by a compression fixture. In other examples, the manufacturing apparatus 90 is responsible for applying an initial compressive force to the cell stack 30 to provide the cell stack 46.

The exemplary manufacturing apparatus 90 is a 7-axis device. The example manufacturing apparatus 90 includes, among other things, a first pin 92 and a second pin 96 for direct engagement with the cell stack 46. The manufacturing apparatus 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 engage 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 clamp the load plate 80 and grasp the cell stack 46. Although one first pin 92 and one second pin 96 are shown in this example, other examples may include more than one first pin and more than one second pin.

Referring now to fig. 6-10, the first pin 92 includes a wedge portion 100 having an angled leading edge 104. The second pin 96 is similarly configured with a wedge-shaped portion 106 having an angled leading edge 108.

In this example, after engagement with the cell stack 46, the manufacturing apparatus 90 moves to insert the wedge-shaped portion 100 of the first pin 92 into the cell receiving opening 60. The wedge portion 106 of the second pin 96 also moves into the cell receiving opening 60. The angled leading edge 104 may help guide the insertion of the wedge portion 100 and the wedge portion 106 into the interior region 44 in the direction I (fig. 6).

In this example, the wedge-shaped portion 100 of the first pin 92 and the wedge-shaped portion 106 of the second pin 96 are inserted into the cell receiving opening 60 prior to the cell stack 46. The wedge portion 100 of the first pin 92 and the wedge portion 106 of the second pin 96 may be inserted to enlarge the cell receiving opening 60. Enlarging the cell receiving opening 60 facilitates insertion of the cell stack 46 into the cell receiving opening 60 of the housing tray 54.

Specifically, during insertion, the wedge portion 100 of the first pin 92 and the wedge portion 106 of the second pin 96 press against the side wall 56 of the housing tray 54 to flex the side wall 56 outwardly in the direction O, as shown in fig. 7. This stretches the housing tray 54. The outward flexing of the side walls 56 changes the size of the cell receiving opening 60. The amount of movement of the side wall 56 may be less than five millimeters.

After inserting the wedge-shaped portion 100 of the first pin 92 and the wedge-shaped portion 106 of the second pin 96 into the interior region 44 to change the size of the cell receiving opening 60 as shown in fig. 8, the pusher 112 of the manufacturing apparatus 90 extends from the retracted position to the extended position. The pusher extension pushes the cell stack 46 into the cell receiving opening 60 from the position of fig. 8 to the position of fig. 9. The load plate 80 of the cell stack 46 slides relative to the first pin 92 and the second pin 96 when pushed by the pusher 112. In this example, the cell stack 46 is pushed in a direction perpendicular to the axis a of the cell stack and inserted into the cell receiving opening 60.

The first pin 92 and the second pin 96 may then be withdrawn from the cell receiving opening 60, as shown in fig. 10, while the pusher 112 maintains the position of the cell stack 46. This disengages the fabrication equipment 90 from the cell stack 46. The side walls 56 of the housing tray 54 then spring back inwardly against the load plate 80. The inward movement of the side walls 56 reduces the sides of the cell receiving openings and responds to disengagement.

After the first pin 92 and the second pin 96 are removed, the example cell stack 46 may expand slightly along the axis a, thereby bringing the load plate 80 into direct contact with the side walls 56 of the housing tray 54. Direct contact of the side walls 56 with the load plate 80 maintains some compressive force on the cell stack 46. This process is repeated to load the remaining cell stacks 46 into the housing tray 54.

After the cell stack 46 and other components 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 (15)

1. A battery pack assembly method, comprising:

engaging the housing structure with a manufacturing apparatus;

changing the size of a cell receiving opening in the housing structure using the manufacturing apparatus;

inserting at least one cell stack into the cell receiving opening; and

the manufacturing apparatus is disengaged from the housing structure.

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

3. The method of claim 1, wherein the altering is after the engaging.

4. The method of claim 1, further comprising compressing the at least one cell stack with the housing structure after the disengaging.

5. The method of claim 1, wherein the changing increases a size of the cell receiving opening, and optionally wherein the size of the cell receiving opening decreases in response to the disengaging.

6. The method of claim 1, wherein the enclosure structure comprises an enclosure ring, and optionally wherein the enclosure structure is an enclosure tray.

7. The method of claim 1, wherein the housing structure is a metal or metal alloy, and optionally wherein each cell stack is disposed along a respective cell stack axis, wherein the inserting moves the at least one cell stack relative to the housing structure in a direction perpendicular to the cell stack axis.

8. The method of claim 1, wherein the housing structure circumferentially surrounds the cell stack after the inserting.

9. The method of claim 1, further comprising compressing the at least one cell stack during the inserting.

10. The method of claim 1, further comprising changing a size of the cell receiving opening by inserting at least one wedge portion into the cell receiving opening, and optionally wherein the at least one wedge portion comprises a wedge portion of a first pin and a wedge portion of a second pin, and the method further comprises moving the at least one cell stack into the cell receiving opening from a position in which the first pin and the second pin retain the at least one cell stack during the inserting.

11. A traction battery pack assembly, comprising:

at least one cell stack is arranged; and

a housing structure having a cell receiving opening that varies in size to receive the at least one cell stack, the housing structure compressing the at least one cell stack.

12. The traction battery pack assembly of claim 11 wherein the housing structure is a housing tray.

13. The traction battery pack assembly of claim 11 wherein the housing structure is a metal or metal alloy.

14. The traction battery pack assembly of claim 11 wherein the at least one cell stack comprises a first cell stack having a plurality of individual cells disposed along an axis, the housing structure compressing the plurality of individual cells of the at least one cell stack along the axis.

15. The traction battery pack assembly of claim 11 wherein the cell receiving opening is within a housing ring provided by a plurality of sidewalls of a housing tray, and optionally wherein the housing structure circumferentially surrounds the at least one cell stack.