Relay Contact Unfreezing Control Without Unwanted Switching

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Solution Overview

Problem

Existing relay systems face challenges in quickly addressing freezing on contacts while minimizing the risk of reduced lifespan and undesired mode switching during the unfreezing process.

Innovation Solution

A relay system with a controller that applies a large amount of electric current to the driving mechanism in a direction that maintains the contacts in a stable state, preventing switching between open and closed modes, thereby generating sufficient heat for rapid unfreezing without damaging the contacts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a large amount of electric current is applied to the coil to generate sufficient heat for rapid unfreezing, then the unfreezing speed is improved, but the contact may undesirably switch between open and closed modes during the process

Engineering Contradiction:

Improveunfreezing speedVSAvoidcontact mode stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies dynamic control by switching between two different current application modes: first applying a large current to rapidly unfreeze the contact, then switching to a smaller maintaining current to prevent mode switching. This dynamic adjustment of current levels allows the system to achieve both rapid unfreezing and operational stability.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent employs periodic action through a two-stage current application process. The first stage applies high current for a limited duration to generate heat for unfreezing, then the second stage applies a smaller maintaining current to stabilize the contact position. This periodic switching between different current levels resolves the contradiction between speed and stability.

Inventive Principle:

Principle #19Periodic action

2Object-affected harmful factors

If electric current is applied to the coil to heat the contact for unfreezing, then the freezing is removed, but the contact may switch between open and closed modes causing premature wear

Engineering Contradiction:

Improvefreezing on contactVSAvoidcontact lifespan

Core Design Contradiction:

Object-affected harmful factorsVSDuration of action of stationary object

Solution Approach 1:

The patent applies partial action by using a large current only for the specific purpose of unfreezing the contact, then switching to a smaller maintaining current. This partial application of excessive current achieves the unfreezing goal without continuously subjecting the contact to high stress that would cause premature wear.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The patent provides beforehand cushioning by applying a smaller maintaining current after the unfreezing process to prevent the contact from switching modes. This maintaining current acts as a cushioning force that protects the contact from the harmful effects of repeated switching and extends its operational lifespan.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If the relay controller continuously applies small electric current to prevent mode switching, then the contact stability is improved, but the heat generation is insufficient for rapid unfreezing

Engineering Contradiction:

Improvecontact mode stabilityVSAvoidunfreezing efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent dynamically switches between two current application strategies: first applying a large current to generate sufficient heat for rapid unfreezing, then transitioning to a smaller maintaining current to ensure contact stability. This dynamic approach allows the system to achieve both high unfreezing efficiency and reliable contact stability at different stages.

Inventive Principle:

Principle #15Dynamics

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 system effectively and quickly unfreezes contacts by generating substantial heat without switching modes, reducing the risk of premature wear and ensuring timely operation.

Implementation Method 1

a driving mechanism configured to switch the contact between an open mode and a closed mode

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

commence first application of electric current to the driving mechanism to generate a driving force... generating sufficient heat for rapid unfreezing

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Data Source

PatentUS12362117B2Relay system

Publication Date: 2025.07.15 SUBARU CORP

AI summary

A relay system includes a relay device and a controller. The relay device includes a contact and a driving mechanism configured to switch the contact between an open mode and a closed mode. The controller is configured to control the relay device. The controller is configured to, when freezing occurs on the contact, to commence first application of electric current to the driving mechanism to generate a driving force acting in a direction in which the contact is not switched between the open mode and a closed mode.