Terminal Fitting Flat Contact Portion Vibration Stability
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Solution Overview
Problem
Existing terminal fittings experience contact instability due to loose movement of the tab under vibration, which can lead to impaired connection stability and operability issues.
Innovation Solution
A terminal fitting design featuring a contact portion with a flat surface that gradually widens from the insertion start to the end, allowing for flat contact with the tab and providing support through symmetrically arranged receiving portions to prevent edge contact and stabilize the connection, while reducing initial insertion resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a point contact structure is used between the contact portion and the tab, then the initial insertion resistance is reduced, but the contact stability deteriorates under vibration due to loose movement and streaking
Solution Approach 1:
The contact portion transitions from a point contact configuration to a flat surface configuration, fundamentally changing the contact parameter from zero-dimensional to two-dimensional. This parameter change enables the contact surface to accommodate tab movement under vibration while maintaining stable electrical connection, preventing the streaking issue that occurs with point contacts.
Solution Approach 2:
The invention introduces a new dimension to the contact interface by creating a flat surface contact portion that extends in multiple directions. This dimensional expansion from point contact to surface contact provides tolerance for tab displacement in both widthwise and longitudinal directions, thereby maintaining contact stability under vibrational conditions.
2Reliability
If a flat contact surface is used between the contact portion and the tab, then the contact stability is improved, but the initial insertion resistance increases
Solution Approach 1:
The flat surface of the contact portion is designed with a gradual slope from the front end to the rear end, creating a dynamic insertion path. This dynamic geometry allows the tab to gradually engage with the contact surface during insertion, reducing initial resistance while ensuring that the full flat surface contact is achieved at the proper insertion depth, thereby maintaining both ease of operation and contact stability.
Solution Approach 2:
The contact portion features non-uniform local geometry with the flat surface area gradually increasing from front to rear. This local quality variation creates a progressive engagement mechanism where the smaller front area reduces insertion resistance while the larger rear area provides stable contact, resolving the contradiction between ease of insertion and contact stability.
3Reliability
If the contact portion is positioned to cross over the facing ends of the tab, then the contact stability is improved by preventing edge contact, but the device complexity increases
Solution Approach 1:
The invention merges the contact function and the tab support function into a single integrated flat surface contact portion. This unified structure eliminates the need for separate edge-protection features while inherently preventing edge contact through its geometric design, thereby improving contact stability without significantly increasing device complexity.
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 design enhances contact stability by preventing edge contact and maintaining flat contact even under vibration, and improves operability by reducing initial insertion resistance through a gradually widening flat surface.
Implementation Method 1
a resilient touching piece 12 which is resiliently deformably formed in the main portion 11
Data Source
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AI summary
An object of the present invention is to ensure contact stability with a tab. A female terminal fitting 10 is provided with a box-shaped main portion 11 into which a mating tab 61 is insertable, and a resilient touching piece 12 having a projection as a contact portion 32 that can come into contact with the tab 61 is provided in the main portion 11. The tab is formed by folding the opposite widthwise end portions of a metal plate in thickness direction and causing the end edges of the folded parts to face each other. A flat surface 35 of the contact portion 32 comes into flat contact with the tab 61 while crossing over the facing ends 64 when the tab 61 is properly inserted into the main portion 11. Accordingly, edges 67 of the facing ends 64 do not sharply act on the contact portion 32, wherefore it can be prevented to streak the contact portion 32.