Terminal-Equipped Covered Electric Wire Dual-Layer Resin Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing resin cover portions for electrical connections in vehicle terminals are prone to deformation and damage during insertion into connector housings, leading to potential corrosion due to insufficient adhesiveness and elastic modulus, which allows water infiltration.
Innovation Solution
A terminal-equipped covered electric wire with a resin cover portion comprising a first layer of thermoplastic elastomer for high adhesiveness to the terminal fitting and a second layer of polyester resin with a high elastic modulus to prevent damage and ensure strong adhesion, with an adhesive strength of 1.3 MPa or more between the layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a polyamide resin is used for the resin cover portion, then the resin cover portion has good adhesiveness to the terminal fitting, but the resin cover portion is prone to deformation and damage during insertion into the connector housing
Solution Approach 1:
The resin cover portion is constructed as a composite material consisting of a polyamide resin layer (providing adhesiveness to the terminal fitting) and a polyester resin layer (providing high elastic modulus and damage resistance). This composite structure allows both materials to work together, with each layer performing its specialized function, thereby resolving the contradiction between adhesiveness and damage resistance
Solution Approach 2:
The resin cover portion is divided into two distinct functional layers: an inner layer of polyamide resin that provides adhesiveness to the terminal fitting, and an outer layer of polyester resin that provides high elastic modulus and resistance to damage during insertion. This segmentation allows each layer to be optimized for its specific function without compromising the other
2Reliability
If a resin material with high elastic modulus is used for the resin cover portion, then the resin cover portion resists damage during insertion, but the resin material has insufficient adhesiveness to the terminal fitting surface
Solution Approach 1:
The resin cover portion combines a polyester resin layer (providing high elastic modulus and damage resistance) with a polyamide resin layer (providing adhesiveness to the terminal fitting). This composite structure allows the polyester resin to provide mechanical strength while the polyamide resin ensures proper adhesion, resolving the contradiction between damage resistance and adhesiveness
Solution Approach 2:
Different regions of the resin cover portion are assigned different material properties: the inner layer in contact with the terminal fitting uses polyamide resin for adhesiveness, while the outer layer exposed to mechanical stress uses polyester resin for high elastic modulus and damage resistance. This local differentiation of material quality allows each region to perform its specific function optimally
Data Source
AI summary
A terminal-equipped covered electric wire and a wire harness in which an electrical connection portion where a terminal fitting and an electric wire conductor are electrically connected is covered with a resin cover portion. With the terminal-equipped covered electric wire and the wire harness, the terminal fitting is prevented from being damaged during insertion into a connector housing, and the resin cover portion has improved adhesiveness to the terminal fitting. Provided is a terminal-equipped covered electric wire in which a resin cover portion covering an electrical connection portion includes a first layer made of a thermoplastic elastomer having adhesiveness to the surface of a terminal fitting, and a second layer made of a polyester resin. The adhesive strength between the thermoplastic elastomer and the polyester resin is 1.3 MPa or more. A wire harness including such a terminal-equipped covered electric wire is configured.