Segmented Downholder Clamping for Battery Cell Tolerance Compensation
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Solution Overview
Problem
The existing methods for connecting rechargeable cells in batteries are inefficient due to tolerance issues and require significant time and effort, potentially leading to damage from excessive clamping force and necessitate frequent repositioning of the clamping device and laser weld head.
Innovation Solution
A clamping device with separate downholders that can be tensioned against each cell, allowing for simultaneous clamping of multiple cells without moving the clamping device or laser weld head, using elastic downholders to compensate for tolerances and provide a gap-free connection, and a welding device with multiple laser weld heads for efficient connection of cells to cell connectors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single clamping device is used for multiple cells, then device complexity is reduced, but manufacturing precision deteriorates due to tolerance accumulation
Solution Approach 1:
The clamping device is divided into multiple independent downholders, each responsible for clamping one cell. This segmentation allows each downholder to independently adapt to the dimensional tolerances of individual cells, maintaining high connection precision without requiring an overly complex unified structure.
2Reliability
If clamping force is increased to ensure gap-free connection, then connection reliability improves, but cell damage risk increases
Solution Approach 1:
Each downholder is equipped with an independent spring element that provides locally adapted clamping force. The spring constant and preload can be optimized for the specific cell type, ensuring sufficient contact pressure for reliable welding while preventing excessive force that could damage the cell.
3Adaptability or versatility
If the clamping device is repositioned for each cell, then adaptability to cell tolerances improves, but productivity decreases due to repeated positioning
Solution Approach 1:
The downholders incorporate spring elements that dynamically adapt to the actual position and dimensions of each cell through elastic deformation. This dynamic adaptation eliminates the need for precise repositioning of the entire clamping device for each cell, significantly reducing cycle time while maintaining tolerance compensation.
4Productivity
If multiple cells are clamped simultaneously, then productivity improves, but clamping force distribution becomes difficult to control
Solution Approach 1:
The clamping device uses multiple independent downholders, each with its own spring element, to clamp multiple cells simultaneously. This segmentation ensures that each cell receives independently controlled clamping force through its respective spring, maintaining proper force distribution across all cells without interference from adjacent clamping actions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces cycle times in battery production by allowing for precise adaptation to cell dimensions, avoiding damage from excessive force, and enabling welding of multiple cells without repositioning, thereby improving the efficiency and reliability of the connection process.
Implementation Method 1
at least one downholder (7) is assigned to the at least one cell (3), by means of which the at least one downholder (7) can be tensioned against the at least one cell (3), wherein the at least one downholder (7) has or have a spring element (12)
Implementation Method 2
the at least one downholder (7) has or have a spring element (12), in particular a coil spring (12)
Implementation Method 3
a laser beam is directed at the cell connector from a laser weld head of the welding device
Implementation Method 4
a laser beam is directed at the cell connector from a laser weld head of the welding device, and the cells are held in a clamping device
Data Source
AI summary
A clamping device for clamping at least one cell for storing electrical energy includes a downholder ,by which a cell connector can be placed on the cell or the cells without gaps at least in some sections, wherein for each cell a separate downholder is provided, wherein the downholder(s) can be tensioned against the cell or the cells.