Battery Rivet With Variable Thickness For Reliable Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing battery sealing technologies face challenges in reliably sealing around the through hole of a battery case due to inadequate pressure transmission and elastic restoration issues with hollow rivets, leading to inconsistent sealing and potential base portion fusion during high current flow.
Innovation Solution
A battery design featuring a rivet with a tubular portion that increases in thickness from one end to the other, allowing for effective pressure distribution and reduced elastic restoration, combined with a manufacturing method that includes using a puncher to form a recessed tubular portion in the rivet, ensuring reliable sealing and preventing base portion fusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a solid rivet is used with a long distance from one end to central portion, then the rivet can be inserted through the through hole, but the applied pressure cannot be transmitted to the central portion effectively, preventing sufficient expansion of the central portion diameter
Solution Approach 1:
The rivet is designed with non-uniform thickness, featuring a thicker first portion and a thinner second portion. This local quality variation allows the thicker first portion to effectively transmit swaging pressure to expand the central portion diameter for reliable sealing, while the thinner second portion facilitates easier insertion through the through hole and reduces material usage.
2Force
If a hollow rivet is used to expand the central portion diameter, then pressure can be transmitted, but the expanded diameter becomes smaller due to elastic restoring force of the hollow tubular portion
Solution Approach 1:
The rivet employs a non-uniform thickness design with a thicker first portion that provides sufficient material density to resist elastic restoration, maintaining the expanded central portion diameter for reliable sealing. The thinner second portion remains hollow to allow pressure transmission during swaging while reducing overall material usage.
Solution Approach 2:
The rivet combines solid and hollow structural elements in a composite design, where the thicker first portion acts as a solid core for maintaining expansion against elastic restoration, while the thinner hollow second portion facilitates pressure transmission and insertion.
3Ease of operation
If a hollow rivet with even and thin tubular portion thickness is used, then the rivet can be inserted easily, but the base portion can be fused when high current flows through the rivet
Solution Approach 1:
The rivet features a non-uniform thickness design where the first portion is thicker to serve as a robust base that can dissipate high current without fusion, while the second portion is thinner to facilitate easy insertion through the through hole. This local quality variation resolves the contradiction between ease of insertion and resistance to high current effects.
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
The solution achieves reliable sealing around the battery case through enhanced pressure distribution and reduced elastic restoration, maintaining a sealed state even under high current conditions while preventing base portion fusion.
Implementation Method 1
as a distance from the one end of the rivet 21 to a central portion 21A in the axial direction (a length of an arrow in Fig. 7A) is long and the applied pressure may not easily be transmitted to the central portion 21A of the rivet 21 in the axial direction
Implementation Method 2
the diameter of the central portion 27D in the axial direction that is once expanded can become smaller due to an elastic restoring force of a lower tubular portion 27A
Implementation Method 3
reduced elastic restoration, maintaining a sealed state even under high current conditions
Data Source
Figure 1A~1B
Figure 2A~2C
Figure 3A~3B
AI summary
The present invention provides a battery including a rivet either inserted into a through hole defined in a lid of a battery case with gaskets and interposed therebetween, the rivet connecting a current collector connected to a power generating element within the battery case and an external terminal. One end of the rivet in the axial direction is connected to the current collector, and provided with a tubular portion recessed in the axial direction, the tubular portion is defined in one of such manners that a bottom surface of the tubular portion reaches the lid of the battery case and that the bottom surface is positioned on a side of the other end beyond the lid of the battery case, and a thickness of the tubular portion increases from the one end toward the other end.