Splice Waterproofing Structure for Unequal Wire Bundles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wire harnesses with splice portions face challenges in maintaining high waterproofing performance, especially when exposed to varying temperatures, due to thermal stress between different materials, leading to potential separation of the waterproofing portion from the insulating coverings.
Innovation Solution
A wire harness design featuring a longer covering length for the first wire bundle with more wires, where the waterproofing cover integrates with both wire bundles, using a resin material that maintains adhesive strength even at high temperatures, effectively mitigating thermal stress and preventing separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a waterproofing member covers the splice portion, then waterproofing performance is improved, but thermal stress causes separation between the waterproofing member and insulating coverings under temperature changes
Solution Approach 1:
The waterproofing member is designed with different covering lengths for different wire bundles. The first wire bundle receives a longer covering length than the second wire bundle, creating local differentiation in the waterproofing structure. This local quality variation allows the waterproofing member to better accommodate thermal expansion and contraction differences across the splice portion, reducing stress concentration and preventing separation while maintaining waterproofing performance.
2Reliability
If the waterproofing cover uses a resin material, then waterproofing property is enhanced, but thermal stress increases due to material expansion differences
Solution Approach 1:
The invention changes the geometric parameter of the waterproofing member by implementing asymmetric covering lengths. The first covering length for the first wire bundle is longer than the second covering length for the second wire bundle. This parameter variation allows the waterproofing member to flexibly adapt to thermal stress distribution, reducing overall stress while maintaining the waterproofing benefits of the resin material.
3Ease of manufacture
If the waterproofing member covers both wire bundles equally, then manufacturing is simplified, but waterproofing performance decreases due to insufficient coverage of the larger wire bundle
Solution Approach 1:
The waterproofing member is designed with an asymmetric structure where the covering length varies across different wire bundles. Specifically, the first covering length for the first wire bundle is longer than the second covering length for the second wire bundle. This asymmetric design ensures that the larger first wire bundle receives adequate waterproofing coverage while the splice portion remains protected, thereby improving waterproofing performance without significantly complicating the manufacturing process.
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 significantly reduces thermal stress at the edges of the waterproofing portion, ensuring a high waterproofing property is maintained even under temperature changes, suitable for environments like automobile interiors.
Implementation Method 1
a waterproofing cover that integrally covers the splice body, the outer surfaces of the insulating coverings of the first wire bundle, and the outer surfaces of the insulating covering of the second wire bundle with a resin material
Data Source
AI summary
A wire harness including: a first wire bundle that includes a plurality of wires; a second wire bundle that includes fewer wires than the first wire bundle; a splice body; and a waterproofing cover, wherein: the wires of the first wire bundle and the second wire bundle each include a conductor and an insulating covering that covers an outer circumference of the conductor, and each include an exposed portion at which the conductor is exposed from the insulating covering, at the splice body, the exposed portions of the first wire bundle and the exposed portions of the second wire bundle are bonded, and the waterproofing cover integrally covers the splice body, the outer surfaces of the insulating coverings of the first wire bundle, and the outer surfaces of the insulating covering of the second wire bundle with a resin material.