Relay Contact Yoke Layout for Arc Deflection and Contact Protection

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Solution Overview

Problem

Existing contact devices are susceptible to being affected by arcs during switching between conduction and non-conduction, which can lead to contact deterioration, especially in electromagnetic relays with large currents.

Innovation Solution

A contact device with a yoke arranged adjacent to the movable contact maker to enhance magnetic flux intensity, directing arcs away from the contacts and extinguishing them quickly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If contacts are brought into contact and separated to switch between conduction and non-conduction, then switching function is achieved, but arcs are generated that affect and deteriorate the contacts

Engineering Contradiction:

Improvecontact reliabilityVSAvoidarc effect on contacts

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A yoke is introduced as an intermediary component between the contacts and the external environment. The yoke provides a magnetic flux path that mediates the arc behavior, directing it away from the contacts through its magnetic properties, thereby protecting the contacts from direct arc damage while maintaining the switching function

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention converts the harmful arc effect into a beneficial phenomenon by utilizing the arc's magnetic field to drive the arc along the yoke's surface. The yoke's magnetic properties transform the destructive arc into a controlled magnetic flux path that extinguishes the arc away from the contacts, turning the harmful factor into a protective mechanism

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 yoke configuration effectively directs and extinguishes arcs, preventing contact damage and ensuring reliable operation even with AC currents.

Implementation Method 1

A contact device with a yoke arranged adjacent to the movable contact maker to enhance magnetic flux intensity, directing arcs away from the contacts and extinguishing them quickly

Methodology Applied

Scientific EffectMagnetic flux: Magnetic Field

Implementation Method 2

directing arcs away from the contacts and extinguishing them quickly

Methodology Applied

Scientific EffectArc: Electric Arc

Data Source

PatentEP4117007B1Contact device

Publication Date: 2025.07.23 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

Figure 1(a)~1(b)
Figure 2(a)~2(b)
Figure 3

AI summary

Provided is a contact device (30) including a first contact (311), a second contact (321) that is movable relative to the first contact (311) and is brought into contact with or separated from the first contact (311), a first body part (312) including the first contact (311), a second body part (322) including the second contact (321), and a yoke (40) arranged adjacent to at least one of the first body part or the second body part. At least a part of the yoke (40) is arranged along magnetic flux (B) generated by a current (I) flowing through one body part of the first body part and the second body part that is adjacent to the yoke, in a region (R1) where the first body part (312) and the second body part (322) overlap each other when viewed along an axis in which the first contact (311) and the second contact (321) move relative to each other while the first contact (311) and the second contact (321) are in contact with each other.