Elliptical Sealing Rib Geometry for Rectangular Terminal Insertion
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Solution Overview
Problem
Cable holes in seals with low-hardness silicone materials face issues in new oil-resistant environments, leading to high insertion force, damage, and reduced sealing performance due to excessive interference fit or interference fit reduction.
Innovation Solution
A seal design with an elliptical inner contour line for inner sealing ribs that matches the major and minor axes of a rectangular terminal, ensuring interference fit and preventing damage, combined with outer sealing ribs for additional sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the inner diameter of cable holes is increased directly to reduce insertion force, then the insertion force is reduced, but the interference fit between cable holes and cables becomes excessively small, reducing contact pressure and sealing ability
Solution Approach 1:
The cable hole is designed with an elliptical cross-section rather than a circular one, creating asymmetric dimensions where the major axis provides sufficient clearance for easy cable insertion while the minor axis maintains adequate interference fit for sealing. This asymmetric geometry resolves the contradiction by allowing different functional requirements to be met along different axes of the same hole.
Solution Approach 2:
The elliptical cable hole creates localized quality differences in the interference fit distribution. The minor axis region provides high contact pressure for sealing, while the major axis region provides clearance for insertion. This local differentiation allows the same hole to simultaneously satisfy both sealing requirements and insertion force requirements.
2Adaptability or versatility
If oil-resistant materials with high hardness are used to replace low-hardness silicone, then oil resistance is improved, but toughness deteriorates and excessive force is required to insert terminals and cables
Solution Approach 1:
The elliptical cable hole design compensates for the high hardness of oil-resistant materials by providing increased clearance in the major axis direction, reducing insertion force despite the material's toughness. The asymmetric geometry allows the hard material to maintain its oil resistance while the hole shape facilitates easier insertion.
Solution Approach 2:
The invention changes the geometric parameters of the cable hole from a circular cross-section to an elliptical one, specifically increasing the major axis dimension relative to the cable diameter. This parameter change reduces the interference fit in the insertion direction while maintaining sealing capability through the minor axis, thereby easing insertion of terminals and cables into oil-resistant seals.
3Device complexity
If rectangular-section terminals are inserted into circular cable holes, then the structure is simple, but the major sides of terminals scrape the edges of cable holes, leading to poor sealing
Solution Approach 1:
The elliptical cable hole is oriented such that its major and minor axes align with the major and minor sides of the rectangular terminal respectively. This asymmetric alignment prevents the major sides of the terminal from scraping the edges of the hole during insertion, as the elliptical geometry provides adequate clearance in the major axis direction while maintaining proper contact for sealing.
Solution Approach 2:
The elliptical cross-section creates localized contact regions that match the rectangular terminal geometry. The minor axis region provides edge-to-edge contact for sealing, while the major axis region provides clearance that prevents scraping. This local quality differentiation resolves the conflict between structural simplicity and sealing performance.
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
Enhances sealing performance and reliability by maintaining interference fit and preventing damage, while allowing easy terminal insertion.
Implementation Method 1
at least one circumferential inner sealing rib formed in the through hole for interference fit with the cable to achieve sealing therebetween
Data Source
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AI summary
The present invention discloses a seal. The seal includes: an elastic body formed with a through hole which allows a rectangular terminal with a cable to pass through; and at least one circumferential inner sealing rib formed in the through hole for interference fit with the cable to achieve sealing therebetween. An inner contour line of the inner sealing rib is elliptical, and a major axis and a minor axis of the elliptical inner contour line respectively correspond to a major side and a minor side of a rectangular section of the terminal, so as to prevent the inner sealing rib from being damaged when the terminal passes through the through hole. The present invention can not only prevent the seal from being damaged when the terminal passes through the through hole of the seal, but can also ensure sufficient interference between the seal and the cable, greatly improving sealing performance and sealing reliability of the seal.