Wire Harness Waterproofing with Conductor Gas Flow Paths
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Solution Overview
Problem
In in-vehicle wire harnesses, the resin material used for waterproofing can penetrate into gaps between conductors, preventing air from escaping and leading to waterproofing failures when exposed to high temperatures, as the expanded air can dislodge the rubber stopper of the waterproofing terminal.
Innovation Solution
A wire harness design with a waterproofing structure that includes a flow path for gas between the strands of the conductors, allowing air to escape, and using a photo-curable resin that is cured instantly to prevent complete penetration of the resin into the gaps, combined with a protective film for enhanced sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the resin material is allowed to fully penetrate into the gaps between the strands constituting the conductors to enhance waterproofing effect, then the waterproofing effect is increased, but the air inside the coating materials is cut off from escaping, causing the rubber stopper to come off due to pressure from expanded air when exposed to high temperature
Solution Approach 1:
The patent applies different properties to different regions of the conductor structure. The gaps between strands are left partially filled with resin material rather than completely filled, creating a gradient structure where the waterproofing effect is achieved at the outer regions while air escape paths are maintained in the inner regions. This local differentiation resolves the contradiction between waterproofing and air venting.
Solution Approach 2:
The gap between strands is segmented into multiple regions: an outer region where resin material penetrates to provide waterproofing, and an inner region where air escape paths are maintained. This segmentation allows the system to simultaneously achieve both waterproofing effect and air venting function by treating different portions of the same structure differently.
2Object-affected harmful factors
If the resin material completely fills the gaps between strands to prevent water intrusion, then waterproofing is improved, but the flow path for gas escape is blocked, leading to waterproofing failure under thermal conditions
Solution Approach 1:
The conductor structure itself serves dual functions: the gaps between strands naturally provide air escape paths while the outer regions provide waterproofing. The structure is designed to be self-sufficient, eliminating the need for additional complex air escape mechanisms while maintaining both waterproofing and venting functions.
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
This design ensures reliable waterproofing by allowing air to escape through the flow paths, preventing the rubber stopper from being dislodged due to pressure from expanded air, and maintaining effective sealing against water intrusion.
Implementation Method 1
using a photo-curable resin that is cured instantly to prevent complete penetration of the resin into the gaps
Implementation Method 2
If at least one of the insulated wires included in such a wire harness is exposed to a high temperature, the air inside the coating material expands
Data Source
AI summary
Provided is a wire harness in which waterproofness of an exposed conductor portion can be ensured, and even when at least one of insulated wires is exposed to a high temperature, a rubber stopper of a waterproofing terminal can be kept from coming off. An outer peripheral surface of an exposed conductor portion where partially exposed conductors of a plurality of insulated wires are joined together, and outer peripheral surfaces of coating material end portions adjacent to the exposed conductor portion, is continuously covered with a waterproofing agent. A gap between adjacent insulated wires is sealed with the waterproofing agent at the coating material end portions adjacent to the exposed conductor portion. At least one insulated wire of the plurality of insulated wires has a flow path through which gas flows, the flow path being created in gaps between strands that constitute a conductor of the insulated wire.