Electromagnetic Relay with Pushing Card for Three-Phase Safety

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Solution Overview

Problem

Existing electromagnetic relays are primarily suited for single-phase circuits and lack functionality for three-phase alternating current, as well as monostable and forced guidance features, which limits their safety and reliability in three-phase applications.

Innovation Solution

The electromagnetic relay design includes multiple contact units with movable and stationary spring parts, a magnetic circuit, and a pushing card mechanism that provides monostable operation, mandatory guidance, and increased creepage distance for improved safety, along with a structure capable of resisting short-circuit currents and monitoring contact states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If electromagnetic relay is designed for single-phase circuit, then the structure is simple, but it cannot be applied to three-phase alternating current

Engineering Contradiction:
Improveapplicability to three-phase alternating currentVSAvoidstructure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The relay is divided into multiple independent contact units (first, second, third contact units) that can be independently configured for different phases. Each contact unit has its own movable spring part and stationary spring part, allowing the relay to handle three-phase alternating current while maintaining modular simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The relay design incorporates multiple contact units that can simultaneously handle single-phase or three-phase alternating current applications. The magnetic circuit part and contact units are configured to provide universal functionality across different electrical systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If contact units are arranged closely to reduce size, then the device is compact, but the creepage distance and air gap are insufficient reducing safety

Engineering Contradiction:
Improvesafety performanceVSAvoiddevice size
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The contact units are arranged in a spatial distribution that optimizes both compactness and safety. The movable spring parts and stationary spring parts are positioned at different locations on the base, creating adequate creepage distance and air gap while maintaining a compact overall structure through three-dimensional arrangement.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If lead-out terminals are located at the same side for convenient wiring, then wiring is easier, but space is congested and short circuits are more prone

Engineering Contradiction:
Improveshort circuit preventionVSAvoidwiring convenience
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The lead-out terminals are strategically positioned at different locations on the base rather than being symmetrically arranged. This asymmetric distribution prevents space congestion, reduces short circuit risk, and maintains wiring convenience through optimized terminal placement.

Inventive Principle:
Principle #4Asymmetry

4Reliability

If armature rotation angle is increased to improve contact gap, then the stroke of pushing card is greater, but the structure becomes more complex

Engineering Contradiction:
Improvecontact gap in open stateVSAvoidarmature structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The armature is designed with a curved or oblique shape rather than a straight configuration. This curved geometry enables greater rotation angle and improved contact gap without requiring additional mechanical components, maintaining structural simplicity while achieving the desired performance.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 solution enhances the relay's safety performance by enabling operation in three-phase alternating current, preventing short circuits, and ensuring reliable contact management through monostable and forced guidance, while maintaining a stable and efficient design.

Implementation Method 1

When the coil (i.e., enameled wire) is energized, electromagnetic force is generated, and the armature is attracted and contacts the pole surface at one end of the iron core

Methodology Applied
Scientific EffectElectromagnetic force: Electromagnetic Induction

Data Source

PatentEP3968351B1Electromagnetic relay
Publication Date: 2024.07.31 XIAMEN HONGFA ELECTROACOUSTIC CO LTD
  • EP3968351B1 patent drawingFigure 1~2
  • EP3968351B1 patent drawingFigure 3~4
  • EP3968351B1 patent drawingFigure 5~6

AI summary

An electromagnetic relay, includes a base (1) and a magnetic circuit part (2), the magnetic circuit part (2) includes a bobbin (21) equipped with an iron core (25) and an enameled wire (24), an armature (23) and a yoke (22) connected to the iron core (25), the bobbin (21) is disposed horizontally on the base (1), the armature (23) is arranged at a knife edge of the yoke (22) and is cooperated with a pole surface (251) of the iron core (25), the electromagnetic relay further includes at least three groups of contact units distributed side by side, each group of contact units respectively includes a movable spring part (3) and a stationary spring part (4), the movable spring part (3) and the stationary spring part (4) are respectively arranged on the base (1) and cooperate with each other correspondingly, the armature (23) is connected to the movable spring part (3) of each of the contact unit through the pushing card (5) to drive the movable spring part (3) to move. The electromagnetic relay of the present disclosure not only suitable for three-phase alternating current, but also has a monostable function, and can use the pushing card (5) to achieve mandatory guidance, thereby improving the safety performance of the present disclosure.