Connector Case Terminal Segmentation for Airtightness
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Solution Overview
Problem
The airtightness of connectors on vehicle alternators is compromised due to thermal expansion differences between resin and metal components, leading to cracks and gaps that allow water and moisture ingress, which is exacerbated by mounting environments and the need for improved electrical communication and control.
Innovation Solution
A connector case design featuring a terminal with an external connection terminal, a middle part, and a resin case terminal, where the middle part is exposed in a concave resin injection part filled with encapsulating resin, preventing crack or gap extension and enhancing airtightness, and optionally incorporating electromagnetic noise-absorbing elements and surge absorbers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the connector case uses insert-molded terminals with resin encapsulation, then the manufacturing efficiency is improved, but the airtightness deteriorates due to cracks and gaps from thermal expansion differences
Solution Approach 1:
The terminal is divided into three distinct parts: external connection terminal, middle part, and resin case terminal. The middle part is specifically designed to be exposed in the resin injection part and filled with encapsulating resin, creating a segmented structure that prevents crack propagation while maintaining manufacturing efficiency through insert molding
Solution Approach 2:
The middle part of the terminal acts as an intermediary element between the external connection terminal and the resin case terminal. By exposing this middle part in the resin injection part and filling it with encapsulating resin, it serves as a buffer zone that absorbs thermal expansion stress and prevents crack extension into the connector part
2Ease of operation
If the connector terminals are exposed to the outside of the encapsulating resin case, then the electrical connection is improved, but water and moisture ingress through cracks and gaps
Solution Approach 1:
Different parts of the terminal have different exposure levels and protection degrees. The external connection terminal is exposed for electrical connection, while the middle part is partially exposed and filled with encapsulating resin for protection, and the resin case terminal is fully enclosed. This local differentiation allows both electrical connection and moisture protection
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 solution significantly increases the airtightness and waterproof capability of the connector case, preventing air leakage up to 150 kPa, compared to conventional designs, without increasing design or manufacturing costs, by sealing gaps and cracks with encapsulating resin.
Implementation Method 1
a crack or a small gap is easily generated between the resin and the insert-molded terminals by heat stress and heat expansion in thermal cycle operation of an internal combustion engine
Data Source
AI summary
A connector case has a connector part, a terminal, and a resin case. The connector part of a concave shape accommodates external connection terminals. One end of the terminal is the external connection terminal. The terminal is inserted in the resin case by insert molding. The connector part, the terminal, and the resin case are integrated in one body. A part of the terminal other than the external connection terminal is exposed to the outside of the resin case as a resin case terminal. The resin case has a resin injection part of a concave shape accommodating a middle part of the terminal between the external connection terminal and the resin case terminal, namely, the middle part is exposed in the resin injection part and is filled with an encapsulating resin completely.