Battery Module Case Tunnel Structure for Weld Burst Prevention
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Solution Overview
Problem
Existing battery module welding processes often result in appearance defects such as weld burst marks due to gas ejection during welding, particularly when welding cases manufactured by different methods, which affects the quality and integrity of the welding portion.
Innovation Solution
The implementation of a tunnel portion between the coupling portions and rib of the module case, which extends in the length direction of the welding portion, helps to distribute and discharge gas pressure, preventing surface swelling and enhancing the welding quality by allowing melted material to fill the tunnel, thus reducing appearance defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If welding is performed on module cases manufactured by different methods, then manufacturing versatility and cost-effectiveness are improved, but appearance defects such as weld burst marks occur due to gas ejection
Solution Approach 1:
The patent extracts the harmful gas ejection from the welding process by providing an escape route through the tunnel portion. The tunnel allows gas to be removed from the welding zone, preventing it from causing appearance defects on the welding surface while maintaining the ability to weld cases from different manufacturing methods.
Solution Approach 2:
The tunnel portion acts as an intermediary structure between the welding zone and the external environment. It provides a controlled pathway for gas ejection, mediating the conflict between welding process requirements and appearance quality by directing gas flow away from the welding surface.
2Manufacturing precision
If a tunnel portion is added to the module case structure, then welding quality and appearance are improved, but device complexity increases
Solution Approach 1:
The tunnel portion is merged with the existing module case structure by forming it as an integrated feature of the coupling portions and rib. Rather than adding a separate component, the tunnel is created by recessing existing structural elements, thereby improving welding quality without significantly increasing overall device complexity.
Solution Approach 2:
The tunnel portion is implemented as a localized feature only at the welding portion of the module case, rather than throughout the entire structure. This allows the complexity to be concentrated only where needed for welding quality improvement, while the rest of the module case maintains its original simple structure.
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 improves the appearance quality and integrity of the welding portion by effectively managing gas ejection during the welding process, reducing the occurrence of weld burst marks and enhancing the bonding force while maintaining manufacturing cost-effectiveness.
Implementation Method 1
a tunnel portion between the rib, the first coupling portion, and the second coupling portion
Implementation Method 2
a welding portion in which a boundary area of the first coupling portion and the second coupling portion is welded
Implementation Method 3
allowing melted material to fill the tunnel
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A battery module according to the present disclosure comprises a cell stack comprising a plurality of battery cells; and a module case covering the outside of the cell stack. A module case comprises a first case comprising a rib and a first coupling portion that has a greater thickness than that of the rib and that is connected to a side of the rib; a second case comprising a second coupling portion facing an upper portion of the rib and a side of the first coupling portion; a tunnel portion formed between the rib, the first coupling portion, and the second coupling portion; and a welding portion in which a boundary area of the first coupling portion and the second coupling portion is welded.