Terminal Metal Fitting Chamfered Deformation Restriction

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Solution Overview

Problem

Conventional terminal metal fittings suffer from excessive deformation of terminal springs due to stress concentration at sharply angled edges, leading to reduced elasticity and reliability of electrical connections.

Innovation Solution

A terminal metal fitting design featuring a chamfered deformation restriction portion and a supporting point portion that restricts deformation within a preset range, reducing stress concentration and promoting smoother sliding, thereby suppressing terminal spring deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a through-hole with a sharply angled edge is used to restrict terminal spring deformation, then the terminal spring is prevented from excessive deformation, but stress concentrates at the contact portion causing elastic deformation and loss of reliability

Engineering Contradiction:

Improvereliability of electrical connectionVSAvoidstress concentration

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention replaces the sharply angled edge of the through-hole with a chamfered surface. The chamfered surface provides a gradual transition and curved contact interface instead of a sharp angle, distributing the stress over a larger area and preventing stress concentration that would cause elastic deformation of the terminal spring.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention changes the geometric parameters of the deformation restriction portion by introducing a chamfered surface with specific angles and dimensions. This parameter change transforms the contact interface from a sharp edge to a tapered surface, fundamentally altering how stress is distributed during terminal spring contact.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If the deformation restriction portion has a sharply angled edge, then the structure is simple and easy to manufacture, but the terminal spring deforms elastically and loses its designed elasticity

Engineering Contradiction:

Improveease of manufacture of deformation restriction portionVSAvoidelasticity of terminal spring

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The chamfered surface introduces a curved geometric feature that is still compatible with standard manufacturing processes like CNC machining or mold formation. The curved surface distributes contact stress to preserve terminal spring elasticity while remaining straightforward to manufacture.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Stability of the object's composition

If the terminal spring contacts the sharply angled edge of the through-hole, then deformation is restricted, but the contact portion experiences stress concentration leading to plastic deformation

Engineering Contradiction:

Improvedeformation restriction of terminal springVSAvoidstress at contact portion

Core Design Contradiction:

Stability of the object's compositionVSStress or pressure

Solution Approach 1:

The chamfered surface creates a gradual transition zone that distributes the contact stress over a larger area of the terminal spring. This curved interface prevents stress concentration at a single point, thereby preventing plastic deformation while still restricting excessive spring deformation.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

By changing the geometric parameters of the deformation restriction portion from a sharp edge to a chamfered surface with controlled angles, the stress distribution parameters are fundamentally altered, reducing peak stress values while maintaining deformation restriction functionality.

Inventive Principle:

Principle #35Parameter changes

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 effectively suppresses terminal spring deformation and maintains the necessary elasticity for reliable electrical connections by distributing stress and allowing smoother contact, reducing the likelihood of plastic deformation.

Implementation Method 1

since the portion, to come into contact with the terminal spring, of the deformation restriction portion is chamfered, stress is less prone to concentrate in a contact portion of the terminal spring

Methodology Applied

Scientific EffectStress distribution:

Implementation Method 2

the terminal spring is less prone to plastic deformation... maintains the necessary elasticity for reliable electrical connections

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3588687B1Terminal metal fitting

Publication Date: 2021.11.03 YAZAKI CORP

Figure 1A~1B
Figure 2A~2C
Figure 3A~3B

AI summary

A terminal metal fitting (10) includes a tubular box portion (11) receiving a counterpart terminal; a terminal spring (16) extending from an inner wall surface of the box portion (11) to press and contact to the counterpart terminal; and a deformation restriction portion (17) restricting deformation of the terminal spring (16) within a preset range when the terminal spring (16) contacts to the counterpart terminal. The deformation restriction portion (17) has a chamfered portion (17a) as a portion to contact to the terminal spring (16).