Sealed Battery Current Interrupting Mechanism Weld Reliability
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Solution Overview
Problem
Existing sealed batteries face challenges in reliably welding the conductive and movable members of their current interrupting mechanisms due to dimensional tolerances, leading to potential gaps or deformations that affect weld strength and the ability to interrupt current flow when internal pressure exceeds operating pressure.
Innovation Solution
Incorporating a protruding portion with an annular groove that fractures when internal pressure exceeds the operating pressure, allowing the conductive member to elastically push against the movable member via a weld, ensuring reliable abutment and welding even with offset positions, and featuring a circular through-hole for visual weld state inspection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the thickness of the reversing plate or collector is reduced to make the current interrupting mechanism smaller or lighter, then the weight and size are improved, but deformation occurs more easily making it difficult to ensure abutting surfaces for welding
Solution Approach 1:
The protruding portion is designed to protrude in advance before welding, ensuring that even with dimensional tolerances, the abutting surfaces are reliably contacted. This preliminary positioning action prevents gaps or deformations during the welding process, maintaining weld strength despite reduced thickness.
Solution Approach 2:
The invention changes the geometric parameters of the conductive member by adding a protruding portion with specific dimensions (protruding distance L1, diameter D1) that compensate for thickness reductions. This parameter modification ensures reliable abutment and welding while allowing thinner plates for weight reduction.
2Ease of manufacture
If the position of the reversing plate with respect to the collector is offset due to dimensional tolerance, then manufacturing flexibility is improved, but gaps form between the components making welding difficult and decreasing joint strength
Solution Approach 1:
The protruding portion is pre-formed on the conductive member before assembly, creating a built-in positioning feature that automatically compensates for dimensional tolerances. This preliminary action ensures reliable abutment between the reversing plate and collector regardless of manufacturing variations, maintaining weld reliability.
3Force
If the reversing plate is firmly abutted against the collector due to offset, then contact is ensured, but deformation occurs making it difficult to weld with flat surfaces and creating gaps
Solution Approach 1:
The protruding portion concentrates the contact force locally at its tip rather than distributing it across the entire surface. This localized force application ensures firm contact for reliable welding while preventing deformation of the broader abutting surfaces, maintaining their flatness.
4Difficulty of detecting and measuring
If a through-hole is added to the protruding portion for visual inspection, then quality control is improved, but the structure becomes more complex
Solution Approach 1:
The through-hole enables visual inspection of the weld state by allowing light to pass through and reveal the weld quality. This simple optical inspection method improves quality control without requiring complex detection equipment or procedures.
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 design enhances the reliability of the current interrupting mechanism by ensuring strong and consistent welds, preventing deformation and ensuring reliable interruption of current flow when internal pressure exceeds the operating pressure, while allowing for easy visual inspection of the weld state.
Implementation Method 1
A weld created by welding using an energy beam is interposed between the protruding portion and the moving portion
Implementation Method 2
The protruding portion elastically pushes against the moving portion via the weld
Implementation Method 3
an annular groove that fractures in an annular shape surrounding the weld when the internal pressure exceeds the operating pressure
Data Source
AI summary
A sealed battery (1) is provided with a current interrupting mechanism (62) that interrupts current that flows through an electrode body (10) when an internal pressure (F) of a battery case (80) exceeds an operating pressure (G). The current interrupting mechanism includes a movable member (64) that includes a moving portion (64A) that moves with a rise in the internal pressure, and a conductive member (63) that is electrically connected to the electrode body. The conductive member (63) includes a protruding portion (63A) that protrudes toward the moving portion. A weld (PT) created by welding using an energy beam is interposed between the protruding portion and the moving portion. The conductive member has, around the protruding portion, an annular groove (63BG) that fractures in an annular shape surrounding the weld when the internal pressure exceeds the operating pressure. The protruding portion elastically pushes against the moving portion via the weld.