Electromagnetic Relay Contact Device Arc Extinguishing

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Solution Overview

Problem

Existing electromagnetic relays face issues with foreign substances adhering to the permanent magnet, leading to incomplete contact and malfunction due to inadequate protection during the accommodation process, which affects the breaking performance.

Innovation Solution

The contact device incorporates a dedicated accommodation part for the permanent magnet and yoke within the case, preventing foreign substances from entering and utilizing a magnetic field formed by the permanent magnet and yoke to extinguish arcs efficiently, ensuring reliable contact switching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a permanent magnet is placed close to the movable contact and the fixed contact to elongate and extinguish an arc, then the arc extinction performance is improved, but foreign substances may adhere to the permanent magnet during the accommodation process, causing incomplete contact and malfunction

Engineering Contradiction:
Improvearc extinction performanceVSAvoidforeign substance contamination
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The internal space of the case is divided into a first accommodation space for the permanent magnet and a second accommodation space for the yoke, separated from each other. This segmentation prevents foreign substances from contaminating the permanent magnet while maintaining the magnetic field's effectiveness for arc extinction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A magnetic field serves as an intermediary between the permanent magnet and the arc, allowing the permanent magnet to exert its arc-extinguishing effect without direct exposure to foreign substances in the contact area. The magnetic field transmits the beneficial effect while isolating the permanent magnet from contamination.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If the permanent magnet is exposed during the accommodation process, then the accommodation process is simplified, but foreign substances occurring in the production process may adhere to the permanent magnet, causing malfunction

Engineering Contradiction:
Improveaccommodation process simplicityVSAvoidcontact device functionality
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The case is segmented into separate accommodation spaces, with the permanent magnet housed in a protected first accommodation space. This segmentation maintains manufacturing simplicity while providing inherent protection against foreign substance contamination during the accommodation process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The permanent magnet is pre-positioned within the protected first accommodation space before final assembly, creating a barrier against foreign substances before they can contaminate the magnet during subsequent manufacturing steps.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 design effectively suppresses the decrease in breaking performance by preventing foreign substances from interfering with the contact points and ensures quick arc extinction, maintaining the reliability of the contact device.

Implementation Method 1

a permanent magnet that forms a magnetic field around the fixed contact

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

to elongate and extinguish an arc which occurs when the movable contact moves apart from the fixed contact

Methodology Applied
Scientific EffectArc extinction: Electric Arc

Data Source

PatentEP2945174B1Contact device
Publication Date: 2018.11.14 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP2945174B1 patent drawingFigure 1
  • EP2945174B1 patent drawingFigure 2
  • EP2945174B1 patent drawingFigure 3

AI summary

The fixed contact member includes a fixed contact (3). The movable contact member includes a movable contact (4) and is movable between a position where the movable contact is in contact with the fixed contact and a position where the movable contact is away from the fixed contact. The permanent magnet (14) forms a magnetic field around the fixed contact (3). The case (1) is for accommodating at least the fixed contact member (3) and the movable contact member (4). Further, the case (1) includes an accommodation part (104) which is partitioned from an internal space of the case and is for accommodating the permanent magnet (14) through an opening thereof directed to an outside of the case (1).