Tool assembly and method for filling battery pack with potting material

Abstract

A method for manufacturing a battery includes filling a battery pack with a potting material and clamping the battery pack with a clamp to apply a clamping force on the battery pack when the potting material is located inside the battery pack. The clamp comprises a clamping arm and a rigid base plate. The method further includes maintaining a clamping force on the battery pack when the potting material is foamed to minimize deformation of the battery pack when the potting material is expanded during curing. In addition, the method also includes loosening the battery pack.

Description

TECHNICAL FIELD

[0001] The present invention relates to a tool assembly and method for filling a battery pack with potting material. BACKGROUND

[0002] This section presents generally the background of the disclosure. To the extent that specific experiments are discussed in this section, it should be understood that the disclosure does not limit the inventors to conducting the experiments at the time of filing. The work of the presently named inventors in this regard, and aspects of the description that can not qualify as prior art at the time of filing, are neither expressly nor impliedly admitted to be prior art in the disclosure.

[0003] A battery pack is filled with a potting foam to encapsulate internal components within the battery pack. The pressure exerted by the expanding foam on the battery pack can cause the battery pack to expand and can not meet dimensional tolerances. Therefore, there is a need to develop a tool assembly and method for minimizing the expansion of the battery pack during foam expansion. SUMMARY

[0004] A battery manufacturing method is described. The method includes filling a battery pack with potting material and clamping the battery pack with a clamp to exert a clamping force on the battery pack while the potting material is inside the battery pack. The clamp includes a clamping arm and a rigid base plate. The clamping arm is movable relative to the rigid base plate. The method can also include maintaining the clamping force on the battery pack while the potting material is curing to minimize deformation of the battery pack as the potting material expands during curing, and then releasing the battery pack after the potting material is cured.

[0005] The clamp is part of a tool assembly and the tool assembly includes a spring connected to the clamping arm. The battery pack includes a first shear plate, a second shear plate, and a plurality of battery cells between the first shear plate and the second shear plate. The clamping arm includes an edge clamping portion that is in direct contact with the first shear plate. The clamping arm includes a center clamping portion and the spring is directly connected to the center clamping portion. The clamp also includes a pressure plate. The spring is directly connected to the pressure plate. The pressure plate is configured to be in direct contact with the first shear plate. The rigid base plate is in direct contact with the second shear plate. The tool assembly includes a heat exchanger in thermal communication with the center clamping portion of the clamp. The method can include heating the center clamping portion of the clamp.

[0006] A tool assembly is also described. The tool assembly also includes a clamp that includes a clamping arm and a rigid base plate. The clamp is configured to clamp a battery pack. The tool assembly also includes a nozzle that is in fluid communication with the battery pack. The nozzle is configured to deliver potting material while the clamp exerts a clamping force on the battery pack.

[0007] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the application.

[0008] The above-mentioned and other features and advantages of the presently disclosed systems and methods will be apparent from the detailed description, including the drawings and the examples, which follow. BRIEF DESCRIPTION OF DRAWINGS

[0009] The present application will be more fully understood from the detailed description and the accompanying drawings, in which:

[0010] Figure 1 is a schematic view of a tool assembly for filling a battery pack with potting material.

[0011] Figure 2 is a method for filling a battery pack with potting material using Figure 1 a tool assembly. DETAILED DESCRIPTION

[0012] Reference will now be made in detail to several examples of the present application illustrated in the accompanying drawings. Wherever possible, the same or like reference numbers will be used throughout the drawings and the description to refer to the same or like parts or steps.

[0013] Reference is made to Figure 1The tool assembly 100 is designed to minimize distortion of the battery pack 10 while filling the battery pack 10 with the potting material 102. In the present disclosure, the term “potting material” refers to a polymeric material that can be applied in bulk fluid form (e.g., liquid) and subsequently foamed and become relatively rigid (e.g., solid). The potting material 102 is a thermoset material that forms a chemically foamed foam upon curing. As a non-limiting example, the potting material 102 can be a polyurethane, epoxy, and / or silicone based resin. During curing, the potting material 102 foams and thus expands. The foam expansion caused by the potting material exerts pressure on the battery pack 10. As a result, the battery pack 10 can swell and cause the dimensions of the battery pack 10 to exceed the predetermined dimensional tolerances. The tool assembly 100 exerts a clamping force on the battery pack 10 to control the foam expansion of the potting material 102 while allowing the battery pack 10 to expand to some extent as the potting material 102 cures. The tool assembly 100 includes one or more nozzles 120 in fluid communication with the battery pack 10 to allow the potting material 102 to be delivered into the battery pack 10. While one nozzle 120 is shown, it is contemplated that the tool assembly 100 can include some nozzles 120 at the edges of the tool assembly 100 and other nozzles at the center of the tool assembly 100. The tool assembly 100 minimizes cycle time to produce each battery pack 10 and improves quality by conforming to the dimensional tolerances of the battery pack 10. The tool assembly 100 does not necessarily include the nozzles 120. In this case, the potting material 102 is poured into the battery pack 10 (i.e., the lower shear plate is installed) without a lid. The tool assembly 100 is then clamped in place, and the excess potting material 102 is squeezed out of the gap between the lower shear plate and the TRP tray. Then, as the foam expands, it will press against the controlled displacement table, thereby minimizing its thickness and limiting its overall thickness.

[0014] The battery pack 10 includes a first shear plate 14, a second shear plate 16, and a plurality of battery cells 12 disposed entirely between the first shear plate 14 and the second shear plate 16. The battery pack 10 defines a plurality of voids 18 that are filled with a potable material to maintain the structural integrity of the battery pack 10 during use. The voids 18 are disposed entirely between the first shear plate 14 and the second shear plate 16.

[0015] The tool assembly 100 includes a clamp 101 for exerting a clamping force on the battery pack 10 to minimize deformation of the battery pack 10 as the potting material cures and foams during curing. As such, the tool assembly 100 includes a rigid base plate 106 and a clamping arm 108 that is movable relative to the rigid base plate 106. The clamping arm 108 includes an edge clamping portion 110 and a center clamping portion 112. The edge clamping portion 110 is configured to be in direct contact with the first shear plate 14, thereby providing a rigid load path from the clamping arm 108 to the first shear plate 14 of the battery pack 10. Thus, when the clamping arm 108 exerts the clamping force 104 on the battery pack 10, no deformation occurs at the perimeter of the first shear plate 14. The edge clamping portion 110 of the clamping arm 108 exerts sufficient force and has sufficient rigidity to ensure that the first shear plate 14 seals the housing 20 of the battery pack 10 while allowing the center plate portion 122 of the first shear plate 14 to deform and be up to ten millimeters uneven.

[0016] The clamp 101 also includes one or more springs 114 (e.g., coil springs, wave springs, rubber, foam, hydraulic or pneumatic pistons, air bags, flexible metal plates, etc.) connected to the clamping arm 108. The springs 114 can be located only at the edges of the clamping arm 108 or can be positioned continuously along the length of the clamping arm 108. The springs 114 can first contact the battery pack 10 and can be preloaded. In addition, the clamp 101 also includes a pressure plate 116 connected directly to the springs 114. Thus, the springs 114 can be connected directly to the pressure plate 116. The pressure plate 116 is configured to be in direct contact with the first shear plate 14. Because the pressure plate 116 is connected to the clamping arm 108 by the springs 114, the pressure plate 116 is movable relative to the clamping arm 108, and the springs 114 bias the pressure plate 116 away from the clamping arm 108. Due to the spring connection between the pressure plate 116 and the clamping arm 108, some deformation of the center plate portion 122 (as shown) of the first shear plate 14 can occur as the potting material 102 foams and the clamping arm 108 exerts the clamping force 104 on the battery pack 10. Figure 1

[0017] Optionally, the clamp 101 includes a mechanical stop 118 to limit the deformation of the first shear plate 14 as the potting material 102 foams and the clamping arm 108 exerts the clamping force 104 on the battery pack 10. The mechanical stop 118 is disposed between the clamping arm 108 and the springs 114. It is contemplated that the mechanical stop 118 can have a profiled shape (e.g., wedge-shaped) to allow for gradual deformation of the first shear plate 14 and customized foam expansion.

[0018] ​The center clamp 112 of the clamp arm 108 allows for a controlled amount of deflection in the first shear plate 14 up to a limit provided by a mechanical stop 118. Controlled deflection of the first shear plate 14 is achieved using a spring 114. The spring 114 exerts a spring force to bias the clamp plate 116 away from the clamp arm 108. This spring force can be applied by a fluid, such as an air-filled bladder or a mechanical device such as a pneumatic or hydraulic cylinder.

[0019] The tool assembly 100 can also include a heat exchanger 124 (e.g., an electric heater, a fluid circulation in the tool assembly 100, and / or a fluid circulation in the spring table) in thermal communication with the clamp arm 108. The heat exchanger 124 can be activated to transfer heat from the clamp arm 108 to the potting material 102 inside the battery pack 10. As a result, the potting material 102 can be locally solidified and the clamp time is reduced. The heat exchanger 124 can be independent of the tool assembly 100 and can heat the tool assembly 100 between uses. The heat exchanger 124 can be removed before the clamp 101 is moved into position, allowing the energy stored as heat in the tool assembly 100 to be transferred into the first shear plate 14 to speed up the solidification of the potting material 102. During use, the clamp arm 108 remains in place long enough to solidify the potting material 102 to a state where the potting material 102 is self-supporting and no longer significantly expands the battery pack 10 (e.g., a solid state).

[0020] The tool assembly 100 can also include one or more alignment features (e.g., a positioning pin, a boss, and / or a protrusion) connected to the clamp arm 108. The alignment features 126 are configured to mate with other alignment features (e.g., a positioning hole) in the first shear plate 14 of the battery pack 10 to align the clamp arm 108 with the first shear plate 14. The alignment features 126 also serve to prevent the potting material 102 or other adhesive from clogging clearance holes for fasteners or electrical terminals.

[0021] Figure 2 is a flowchart of a battery manufacturing method 200. The method 200 begins at block 202. Block 202 requires filling the battery pack 10 with the potting material 102 using the nozzle 120. At this point, the first shear plate 14 does not cover the housing 20 of the battery pack 10 and the potting material 102 is in a liquid state. As a result, the potting material 102 can be introduced into the housing 20 of the battery pack 10. The method 200 then continues to block 204.

[0022] At block 204, the first shear plate 14 is placed (and connected to) over the housing 20 of the battery pack 10. Then, while the potting material 102 is inside the battery pack 10, the battery pack 10 is clamped with the clamp 101 to exert a clamping force 104 on the battery pack 10. The clamping force 104 is exerted to the battery pack 10 by the clamping arms 108. Specifically, when the battery pack 10 is positioned between the clamping arms 108 and the rigid substrate 106, the clamping force 104 causes the clamping arms 108 to move toward the rigid substrate 106. The movement of the central clamping portion 112 toward the rigid substrate 106 causes the excess potting material 102 to be extruded through the gap between the battery modules and the housing 20, allowing the potting material 102 to expand with a known force distribution. As described above, the mechanical stop 118 acts as a constraint on the allowable displacement of the potting material 102. Then, the method 200 continues to block 206.

[0023] At block 206, the potting material 102 inside the battery pack 10 is cured by, for example, heating the potting material 102 using the heat exchanger 124. The potting material 102 disposed at the center of the battery pack 10 and the potting material 102 disposed at the edges of the battery pack 10 can have different curing rates. For example, the curing rate of the potting material 102 disposed at the center of the battery pack 10 can be greater than the curing rate of the potting material 102 disposed at the edges of the battery pack 10. The second shear plate 16 can be preheated to assist in curing the potting material 102. The first shear plate 14 can be fastened to the housing 20 while the tool assembly 100 clamps the battery pack 10, holding the first shear plate 14 in place and providing additional structural performance for the final component. Then, the method 200 continues to block 208.

[0024] At block 208, the battery pack 10 is unclamped to remove the tool assembly 100 from the battery pack 10. After the potting material 102 is fully or partially cured, the battery pack 10 can be unclamped. To unclamp the battery pack 10, the clamping arms 108 are moved away from the rigid substrate 106.

[0025] While the foregoing describes exemplary embodiments, it is not intended to describe all possible forms of the claims. The words used in the specification are words of description rather than limitation, and it is to be understood that various changes can be made without departing from the spirit and scope of the application. As previously described, features of various embodiments can be combined to form further embodiments of the presently disclosed systems and methods that can not be explicitly described or illustrated. While various embodiments can be described as having advantages or being superior to other embodiments or prior art implementations, one of ordinary skill in the art recognizes that one or more features or features can be traded off, and that an embodiment having seemingly caused-advantages may, in whole or in part, be desirably substituted for some embodiments having seemingly caused-disadvantages. These attributes can include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, adaptability, weight, manufacturability, ease of assembly, and the like. Accordingly, embodiments described as being more desirable than other embodiments or prior art implementations are not necessarily more desirable, and are not necessarily outside the scope of the present application, and a specific structure can be desirably selected over others depending on a specific application or implementation.

[0026] The drawings are in simplified form and are not drawn to precise scale. Directional terminology, such as top, bottom, left, right, upper, lower, above, below, behind, and in front, is used for convenience only to describe the orientations of the drawings. The directional terminology and like terms are not to be construed as limiting the scope of the application in any manner.

[0027] Embodiments of the application are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and can be carried out in various and alternative forms. The drawings are not necessarily to scale; the certain features can be exaggerated or minimized for the purpose of clarity and precision in illustrating certain components. Specific structural and functional details disclosed herein are not to be interpreted as limiting but as a representative basis for teaching one skilled in the art to employ the systems and methods of the present application in variously modified forms. As those skilled in the art will appreciate, the various features shown and described above in connection with any one figure can be combined with features shown in one or more other figures to produce embodiments that are not explicitly described or illustrated. Combinations of features are contemplated to achieve more straightforward and easier to use embodiments of the presently disclosed systems and methods. It will be appreciated that various

[0028] This description is merely illustrative in nature and is in no way intended to limit the application, its application, or uses. The broad teachings of the application can be implemented in a variety of forms. Therefore, while this application includes particular examples, the true scope of the application should not be limited to such examples.

Claims

1. A battery manufacturing method, comprising: Battery packs are filled with potting materials; When the potting material is inside the battery pack, the battery pack is clamped by a clamp to apply a clamping force to the battery pack, wherein the clamp includes a clamping arm and a rigid substrate, and the clamping arm is movable relative to the rigid substrate; As the potting material cures, a clamping force is maintained on the battery pack to minimize deformation of the battery pack as the potting material expands during curing. as well as The battery pack is released after the potting material has cured.

2. The method according to claim 1, wherein, The clamp is part of a tool assembly, and the tool assembly includes a spring connected to the clamping arm.

3. The method according to claim 2, wherein, The battery pack includes a first shearing plate, a second shearing plate, and a plurality of battery cells located between the first shearing plate and the second shearing plate. The clamping arm includes an edge clamping portion, and the edge clamping portion is in direct contact with the first shearing plate.

4. The method according to claim 3, wherein, The clamping arm includes a central clamping portion, and the spring is directly connected to the central clamping portion.

5. The method according to claim 4, wherein, The clamp also includes a pressure plate, the spring being directly connected to the pressure plate, and the pressure plate being configured to directly contact the first shear plate.

6. The method according to claim 5, wherein, The rigid substrate is in direct contact with the second shear plate.

7. The method according to claim 6, wherein, The tool assembly includes a heater in thermal communication with the central clamping portion, and the method further includes heating the central clamping portion of the clamp.

8. A tool component, comprising: A clamp, the clamp including a clamping arm and a rigid base plate, wherein the clamp is configured to clamp a battery pack; as well as A nozzle in fluid communication with the battery pack, wherein the nozzle is configured to deliver potting material when the clamp applies a clamping force to the battery pack.

9. The tool assembly according to claim 8, wherein, The tool assembly includes a spring connected to the clamping arm.

10. The tool assembly of claim 9, wherein, The battery pack includes a first shearing plate, a second shearing plate, and a plurality of battery cells located between the first shearing plate and the second shearing plate. The clamp includes an edge clamping part that is in direct contact with the first shearing plate.

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