Battery Pack Bus Bar Module Alignment Without Binding Bars
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Solution Overview
Problem
In battery packs employing a Cell-to-Pack structure, there is a need for a precise positioning mechanism for bus bar modules since traditional binding bars are not used, requiring a different mechanism to accurately place bus bars between battery cells without interfering with discharge valves or other structural components.
Innovation Solution
A battery pack design that incorporates a plate member with a positioning mechanism, such as protruding ribs and recesses, to precisely position bus bar modules in the Y axis direction by biasing the case side wall, and additional mechanisms like insertion portions between stacks to position bus bar modules in the X axis direction, ensuring accurate electrical connections without hindering gas discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a Cell-to-Pack structure is used without binding bars, then the battery pack structure is simplified and manufacturing is easier, but a new positioning mechanism must be developed to replace the traditional binding bar positioning
Solution Approach 1:
The battery pack is divided into independent stacks, each with its own bus bar module. The plate member is segmented with multiple positioning mechanisms (first positioning mechanism for Y-axis, second positioning mechanism for X-axis) that can be independently designed and manufactured, simplifying the overall manufacturing process while providing comprehensive positioning functionality.
Solution Approach 2:
The first positioning mechanism uses the side wall of the case as a reaction surface, and the protruding rib automatically positions the bus bar module when the plate member is installed. The mechanism utilizes the existing structural elements (side wall, battery cell surfaces) to provide positioning without requiring additional active components, thereby simplifying manufacturing.
2Manufacturing precision
If the first positioning mechanism is located to bias the side wall of the case, then the bus bar module is precisely positioned in the Y axis direction, but the positioning mechanism must not interfere with the discharge valve operation
Solution Approach 1:
The plate member is designed with locally differentiated properties: in the region where positioning is needed, rigid structure with protruding ribs provides precise positioning; in the region where discharge valves are located, the plate member has through-holes or openings to allow valve operation. This local differentiation allows both positioning precision and valve functionality to be achieved simultaneously.
Solution Approach 2:
The plate member is segmented into functional zones: positioning zones with protruding ribs for Y-axis positioning, and discharge valve zones with through-holes for valve operation. This segmentation allows each zone to optimize its function without interfering with the other, achieving both precise positioning and discharge valve adaptability.
3Manufacturing precision
If protruding ribs are provided on the plate member to abut with battery cell upper surfaces, then frictional resistance is reduced and positioning is improved, but the structure becomes more complex
Solution Approach 1:
The protruding ribs have rounded or curved contact surfaces that abut with the battery cell upper surfaces. This curvature design reduces the contact area to line or point contact, minimizing frictional resistance while maintaining positioning accuracy. The curved surfaces also distribute contact stresses more evenly, preventing localized deformation.
Solution Approach 2:
Instead of adding complex active positioning components to the bus bar module, the positioning function is inverted and built into the plate member structure itself. The protruding ribs are integral to the plate member, transforming the plate member from a simple support structure into an active positioning device, thereby reducing overall system complexity.
Data Source
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AI summary
A battery pack (1) includes: a stack (10) including a plurality of battery cells (100) arranged side by side in a first direction; a case (20) that has a side wall (21) facing the stack (10) in the first direction and that accommodates the stack (10), and a bus bar module (30) disposed on the stack (10), the bus bar module (30) including a bus bar (320) that electrically connects the plurality of battery cells (100) and a plate member (310) that accommodates the bus bar (320), wherein the plate member (310) has a first positioning mechanism (317) that positions the bus bar module (30) in the first direction by biasing the side wall (21) of the case (20).