Closing Plate Corner Geometry to Reduce Battery Case Shaving
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Solution Overview
Problem
The existing manufacturing method for power storage devices results in 'shaving' of the closing corner portions during the insertion of the closing plate into the case, leading to metal powder generation and subsequent spatters and voids during the welding process.
Innovation Solution
The method involves configuring the closing plate with a shorter corner-portion end face length (LK) compared to the long-side end face length (LL), and optionally chamfering the rear face of the closing plate, to reduce shaving and metal powder generation, while ensuring the closing plate is inserted from the rear face side to minimize overlap and deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the closing plate is inserted into the opening of the case to close the opening, then the opening is closed and the device is assembled, but shaving occurs on the closing corner portions generating metal powder that causes spatters and voids during welding
Solution Approach 1:
The patent applies preliminary action by chamfering the outer peripheral edge portion of the closing plate before insertion. This pre-processing creates a beveled surface that guides the closing plate during insertion, preventing the corner portions from contacting and shaving the opening corner portions of the case, thereby eliminating metal powder generation that would cause welding defects
Solution Approach 2:
The patent changes the geometric parameters of the closing plate by creating a chamfer with specific dimensions (first chamfered portion and second chamfered portion with different depths). This parameter modification alters the insertion behavior, allowing the chamfered edges to make contact first and guide the closing plate into proper alignment, preventing corner contact and shaving
2Ease of operation
If the closing plate is inserted with corner portions overlapping opening corner portions, then insertion is achieved, but metal powder is generated and piled on surfaces causing welding defects
Solution Approach 1:
The chamfering process is performed in advance on the closing plate's outer peripheral edge portion. This preliminary action creates a tapered geometry that ensures the chamfered surfaces contact the case opening during insertion, guiding the closing plate into position without the corner portions overlapping and generating metal powder
Solution Approach 2:
The patent converts the potential harmful corner contact into a beneficial guided insertion by chamfering the edges. The chamfered portions, which could be seen as reducing material, actually serve to prevent the much larger harm of metal powder generation and welding defects, turning a material removal process into a protective measure
3Manufacturing precision
If the outer peripheral edge portion of the closing plate is chamfered, then shaving and metal powder generation are reduced, but the device complexity increases
Solution Approach 1:
The patent modifies the closing plate by applying chamfers to the outer peripheral edge portion, changing its geometric parameters from a simple rectangular edge to a beveled configuration. This parameter change reduces shaving and metal powder generation while maintaining the overall simplicity of the closing plate structure
Solution Approach 2:
The chamfering is applied locally only to the outer peripheral edge portion of the closing plate, specifically at the corners where contact with the case opening occurs. This localized modification improves welding quality without requiring complex changes to the entire closing plate 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 configuration reduces the volume of shaved material, decreases metal powder accumulation, and minimizes spatters and voids during the welding process, enhancing the manufacturing efficiency and quality of the power storage device.
Implementation Method 1
the outer peripheral edge portion of the closing plate and the opening wall portion of the case are welded over entire circumferences
Data Source
AI summary
A power storage device manufacturing method is provided. A closing plate used in a closing process includes an outer peripheral edge portion of a rectangular annular shape, which includes a pair of closing long-side portions arranged in parallel to each other, a pair of closing short-side portions arranged in parallel to each other, and four closing corner portions of circular arcuate shape connecting the long-side portions and the short-side portions. The outer peripheral edge portion further includes an outer circumferential end face located on an outermost side of an outer circumferential surface of the closing plate extending in parallel to a thickwise direction of the closing plate. In the outer circumferential end face, a length of a corner-portion end face included in the closing corner portion is shorter in the thickwise direction than a length of a long-side end face included in a closing long-side portion.