Connector Terminal Structure with Stepped Shaft and Insulating Cap

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Solution Overview

Problem

The existing connector terminal structures for high-voltage applications, such as electric vehicles, face challenges in processing complexity and cost due to intricate terminal shapes and the need for precise machining, and there is a risk of damage from annular terminal springs fitting into grooves on male terminals.

Innovation Solution

A connector terminal structure that simplifies the female terminal shape by eliminating the holding groove and externally fits an annular terminal spring to a stepped shaft portion on the male terminal, reducing processing complexity and lengthening the connector, while preventing damage through a secure press-fitting mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a holding groove is formed in the female terminal to hold the terminal spring, then the terminal spring can be secured in place, but the female terminal shape becomes complicated and machining difficulty increases

Engineering Contradiction:

Improveterminal spring retentionVSAvoidfemale terminal machining

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of forming a holding groove in the female terminal to retain the terminal spring, the invention inverts the approach by providing a holding groove in the male terminal. This allows the terminal spring to be retained without complicating the female terminal structure, thereby resolving the contradiction between reliable spring retention and ease of female terminal manufacturing.

Inventive Principle:

Principle #13The other way round (Inversion)

2Reliability

If the terminal spring is assembled inside the female terminal with a holding groove, then the spring can be retained, but the female terminal length increases by the groove depth

Engineering Contradiction:

Improveterminal spring retentionVSAvoidfemale terminal length

Core Design Contradiction:

ReliabilityVSLength of moving object

Solution Approach 1:

The invention moves the holding groove from the female terminal to the male terminal, effectively inverting the retention mechanism location. This allows the female terminal to maintain its original length without the additional depth required for a holding groove, while still achieving reliable terminal spring retention through the male terminal's groove structure.

Inventive Principle:

Principle #13The other way round (Inversion)

3Reliability

If the annular terminal spring is fitted into a groove on the male terminal, then the spring can be retained, but the spring diameter must be increased which may damage the electrical contact portion

Engineering Contradiction:

Improveterminal spring retentionVSAvoiddamage to electrical contact

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention introduces an insulating cap as an intermediary component that fits over the male terminal's electrical contact portion. This cap provides a protective interface that allows the terminal spring to be retained by the holding groove without the spring's expanded diameter directly contacting and potentially damaging the electrical contact surface.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Manufacturing precision

If high precision machining is performed on the male terminal for the holding groove, then the terminal spring can be precisely positioned, but processing cost increases

Engineering Contradiction:

Improveterminal spring positioningVSAvoidprocessing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

By inverting the location of the holding groove from the female terminal to the male terminal, the invention enables the use of more cost-effective machining methods on the male terminal while still achieving precise terminal spring positioning. The male terminal's geometry and material properties allow for precise groove formation without the same cost penalties as female terminal machining.

Inventive Principle:

Principle #13The other way round (Inversion)

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 solution reduces processing costs and shortens the connector length during fitting by simplifying the female terminal shape and prevents damage to electrical contacts by securely holding the annular terminal spring without increasing its diameter, facilitating easier assembly and maintaining high accuracy.

Implementation Method 1

an annular terminal spring including a coil spring having conductivity and being bent in an annular shape

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS11705656B2Connecter terminal structure

Publication Date: 2023.07.18 YAZAKI CORP

AI summary

A connecter terminal structure includes: a male housing of a male connecter; a male terminal accommodated in the male housing and including a first electrical contact portion; a stepped shaft portion formed at a tip end of the first electrical contact portion; a hood portion surrounding the first electrical contact portion; an annular terminal spring externally fitted to the stepped shaft portion; and an insulating cap fixed to a tip end of the stepped shaft portion and configured to hold the annular terminal spring. The connecter terminal structure further includes: a female housing of a female connecter; a female terminal accommodating portion configured to be fitted into the hood portion; and a female terminal accommodated in the female terminal accommodating portion and including a second electrical contact portion having a tubular shape to allow the first electrical contact portion to be inserted therein.