Two-Piece Battery Terminal Layout for Thermal and Vibration Stress
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Solution Overview
Problem
Conventional battery terminals are prone to damage due to thermal and vibration stresses, especially in two-piece configurations where stress concentrations occur at joint portions during the connection process and vehicle travel.
Innovation Solution
A battery terminal with a two-piece configuration using different conductive materials, where the first piece is connected to an external conductive member and the second piece is connected to the power generation element, featuring fixing portions and hole portions arranged to deviate oppositely in the short-side direction, providing enhanced stress resistance through riveting and ultrasonic welding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a two-piece terminal configuration is used to connect power generation element and external conductive member, then connection functionality is improved, but stress concentration at joint portions occurs due to thermal stress and vibration stress
Solution Approach 1:
The patent applies asymmetry by positioning the fixing portion and hole portion at non-symmetric locations on the second piece. Specifically, the fixing portion is located at a position leaning to one side from the center in both longitudinal and short-side directions, while the hole portion is positioned to create an asymmetric arrangement. This asymmetric configuration prevents stress concentration by distributing thermal and vibration stresses more evenly across the joint, avoiding the weakness that would occur at symmetric center positions.
Solution Approach 2:
The patent implements preliminary action by carefully pre-positioning the fixing portion and hole portion during the design and manufacturing stages. The fixing portion is preliminarily placed at an optimized location on the second piece, and the hole portion is preliminarily formed at a corresponding asymmetric position. This preliminary positioning ensures that when the terminal is assembled and subjected to thermal and vibration stresses during vehicle operation, the stress distribution is already optimized to prevent concentration at critical joint points.
2Ease of operation
If fixing portions are positioned at center locations for symmetrical assembly, then assembly ease is improved, but stress concentration occurs at joint portions during thermal and vibration cycles
Solution Approach 1:
The patent deliberately introduces asymmetry in the positioning of the fixing portion and hole portion, moving them away from the geometric center of the second piece. The fixing portion is positioned leaning to one side from the center in both longitudinal and short-side directions, and the hole portion is correspondingly positioned to maintain asymmetric alignment. This asymmetric arrangement sacrifices some assembly simplicity but dramatically improves reliability by preventing stress concentration during thermal expansion and vibration cycles that occur during vehicle operation.
3Reliability
If different conductive materials are used for first piece and second piece, then electrical conductivity is improved, but material compatibility and joint strength become challenging
Solution Approach 1:
The patent applies local quality by using different conductive materials for the first piece and second piece, optimizing electrical conductivity at different locations of the terminal. The first piece (exterior body side) and second piece (power generation element side) can be made of different materials suited for their specific functional requirements. The asymmetric positioning of the fixing portion and hole portion further optimizes the joint area, creating a localized stress distribution pattern that accommodates the different material properties and prevents joint failure.
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 configuration significantly reduces stress on the joint portions, enhancing the battery terminal's resistance to thermal and vibration-induced stresses, ensuring durability and reliability during assembly, bus bar connection, and vehicle travel.
Implementation Method 1
any one of at least a part of the first disk portion and at least a part of the second disk portion is joined to the second face of the second plate-like portion
Implementation Method 2
providing enhanced stress resistance through riveting and ultrasonic welding
Data Source
AI summary
A battery terminal has a two-piece configuration of different types of conductive materials. A first piece placed outside and a second piece placed inside with including a current collecting portion are fixed in two portions of a first fixing portion and a second fixing portion. The first fixing portion is positioned between the current collecting portion and the second fixing portion in a longitudinal direction in a shape of the terminal. Leaning of the current collecting portion with respect to a center in a short-side direction and leaning of the first fixing portion with respect to a center are opposite to each other.