Battery Cap Assembly Interference Fit for Precise Case Welding
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Solution Overview
Problem
The manufacturing process of secondary batteries is hindered by the need for initial tack-welding of the case and cap assembly, which can lead to misalignment and reduced welding quality, affecting productivity.
Innovation Solution
A battery design that includes engagement portions on the cap and case, allowing for an interference fit and limiting movement of the cap assembly, enabling reliable welding without tack-welding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If initial tack-welding of the case and cap assembly is performed, then welding quality is improved, but manufacturing complexity and time are increased
Solution Approach 1:
The cap assembly is pre-positioned on the case using engagement portions (protrusions and recesses) that provide preliminary alignment and positioning before the final welding process. This preliminary mechanical coupling ensures proper alignment without requiring separate tack-welding operations to establish position.
Solution Approach 2:
The engagement portions (protrusions and recesses) act as intermediary mechanical features that facilitate precise positioning and alignment between the cap assembly and case. These features serve as a mediator that enables accurate final welding without requiring preliminary tack-welding operations.
2Productivity
If initial tack-welding is omitted to improve productivity, then manufacturing time is reduced, but alignment precision and welding quality deteriorate
Solution Approach 1:
The cap assembly incorporates engagement portions (protrusions and recesses) that provide preliminary mechanical coupling and positioning with the case before final welding. This preliminary action ensures accurate alignment is achieved through mechanical means rather than through tack-welding, enabling direct progression to final welding and improving productivity.
Solution Approach 2:
The patent replaces the welding-based preliminary fixation method (tack-welding) with a purely mechanical positioning system using engagement portions. This substitution eliminates the need for thermal processes and multiple welding passes, directly improving manufacturing efficiency while maintaining alignment precision.
3Reliability
If engagement portions are added to the cap and case, then alignment and welding reliability are improved, but device complexity increases
Solution Approach 1:
The engagement portions are segmented into discrete protrusions on one component and corresponding recesses on the other component. This segmentation allows for simple, modular features that are easy to manufacture and assemble, minimizing the increase in device complexity while achieving reliable positioning and alignment for improved welding.
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 ensures precise alignment and reliable welding, improving manufacturing efficiency and minimizing damage to the electrode assembly during the welding process.
Implementation Method 1
The at least one first engagement portion of the cap assembly and the at least one second engagement portion of the case may be coupled through an interference fit.
Data Source
AI summary
A battery includes an electrode assembly, a case including a bottom portion, a sidewall portion connected to the bottom portion and including a seating portion at one end thereof, and an upper opening opposite to the bottom portion, the case accommodating the electrode assembly, and a cap assembly that is coupled to the seating portion of the case, wherein the cap assembly includes at least one first engagement portion for coupling with the case, the case includes at least one second engagement portion respectively corresponding to the at least one first engagement portion, the seating portion including the at least one second engagement portion, and the at least one first engagement portion and the at least one second engagement portion are coupled to restrict movement of the cap assembly in an upward direction.