Electromagnetic Relay Contact Inclination Angle for Bounce Reduction

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Solution Overview

Problem

Conventional electromagnetic relays experience significant contact bounce during closure, leading to arc currents and potential failure, which is difficult to mitigate without compromising current-carrying capability or increasing component complexity.

Innovation Solution

The electromagnetic relay is designed with a specified inclination angle (0° < θ < 45°) between the movable and normally open fixed contacts, allowing for reduced repulsion and bounce through elastic interaction, thereby extending contact life without affecting current-carrying capacity or component count.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the fixed contact member is made elastic to reduce contact bounce, then contact bounce is reduced, but current-carrying capability decreases

Engineering Contradiction:
Improvecontact bounce reductionVSAvoidcurrent-carrying capability
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The contact system is divided into two independent parts: the movable contact spring (providing elasticity for bounce reduction) and the fixed contact member (maintaining rigid structure for current carrying). This segmentation allows each component to optimize its function without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The movable contact spring acts as an intermediary element between the actuating force and the contact surfaces. It absorbs the shock of contact closure through its elasticity while the fixed contact member maintains its rigid structure for optimal current carrying capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the fixed contact member is made elastic to reduce contact bounce, then contact bounce is reduced, but component complexity increases

Engineering Contradiction:
Improvecontact bounce reductionVSAvoidcomponent complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The movable contact spring serves dual functions: it provides the necessary elasticity to reduce contact bounce and simultaneously acts as the moving contact element itself. This self-service approach eliminates the need for additional damping components or complex mechanisms.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention changes the physical parameter of the movable contact spring (its elasticity and pre-tension) to achieve bounce reduction. By optimizing the spring constant and initial tension of the movable contact spring, the system reduces contact bounce without requiring structural modifications to the fixed contact member.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If contacts are made parallel to ensure stable contact, then contact stability is improved, but contact bounce increases

Engineering Contradiction:
Improvecontact stabilityVSAvoidcontact bounce
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The movable contact spring introduces dynamic behavior to the contact system. Instead of rigid parallel contacts that cause bounce, the spring provides controlled elastic deformation during contact closure, dynamically absorbing the impact while maintaining stable electrical contact.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The movable contact spring is pre-tensioned to provide cushioning force before contact closure. This beforehand cushioning absorbs the shock of contact bounce through elastic deformation, protecting the contact surfaces from impact damage while ensuring stable contact.

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 configuration effectively prevents initial contact bounce and ensures a longer electrical life for the relay, with optimal results achieved when the inclination angle is between 5° and 20°, significantly reducing arc currents and contact wear.

Implementation Method 1

when a voltage is applied to the coil 1, the movable contact spring 3 and the movable contact 3a move toward a direction A (Fig. 3)

Methodology Applied
Scientific EffectMagnetic field generation: Electromagnetic Induction

Implementation Method 2

the movable contact spring 3 bends with attractive forces of magnetic

Methodology Applied
Scientific EffectMagnetic attraction: Magnetism

Data Source

PatentEP1713104B1Electromagnetic relay
Publication Date: 2013.10.23 TOKIN CORP
  • EP1713104B1 patent drawingFigure 1
  • EP1713104B1 patent drawingFigure 2
  • EP1713104B1 patent drawingFigure 3

AI summary

An electromagnetic relay is provided which is capable of reducing a contact bounce at time of closing a contact. The electromagnetic relay is so configured that an opposed angle θ is 0°&lt;θ&lt; 45°, when viewed from a direction to which a normally open fixed contact (6a) and a movable contact (3a) slide before the normally open fixed contact (6a) comes into surface-contact with the movable contact spring (3). (See Fig. 4)