Electromagnetic Contactor Frame Coupling for Arc Cover Retention

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Solution Overview

Problem

Conventional electromagnetic contactors experience weak fixing force between the arc box and the frame, leading to potential separation during fault currents or repeated arc extinguishing operations.

Innovation Solution

The electromagnetic contactor design incorporates a first coupling part on the lower frame, a second coupling part on the upper frame, and a third coupling part on the arc cover, allowing for secure fastening through a single fastening member, enhancing the coupling force and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional fastening members (rivets, screws) are used to fix the arc box to the frame, then the assembly is simple to manufacture, but the fixing force is weak and the arc box may separate during fault currents

Engineering Contradiction:
Improvefixing forceVSAvoidfastening structure
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent transitions from conventional point-fastening (screws/rivets) to surface-fastening by extending the coupling part along the arc box. This dimensional extension provides a larger fastening area and stronger coupling force while maintaining structural simplicity. The coupling part protrudes from the arc box surface, creating a distributed fastening system that resists separation forces during fault currents.

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

Solution Approach 2:

The fastening structure is segmented into distinct functional parts: the coupling part protruding from the arc box, the receiving part on the frame, and the fastening member connecting them. This segmentation allows each component to be optimized independently - the coupling part for strength, the receiving part for alignment, and the fastening member for secure connection - while simplifying the overall manufacturing process.

Inventive Principle:
Principle #1Segmentation

2Reliability

If multiple separate fastening members are used to secure the arc box to the frame, then the reliability is improved, but the assembly process becomes more complex and time-consuming

Engineering Contradiction:
Improvecoupling stabilityVSAvoidassembly process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges multiple fastening functions into a single integrated fastening member that secures the arc box to the frame. The coupling part and receiving part are designed to work together with one fastening member, eliminating the need for multiple separate fasteners. This reduces assembly complexity and time while maintaining reliability through the distributed coupling design.

Inventive Principle:
Principle #5Merging (Combining)

3Strength

If the coupling part extends the full length of the arc box, then the coupling force is maximized, but the arc box design becomes more complex and material usage increases

Engineering Contradiction:
Improvecoupling forceVSAvoidarc box structure
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The coupling part is designed with local quality by concentrating the fastening function at specific locations where it is most needed for structural integrity. Rather than extending uniformly across the entire arc box, the coupling part is strategically positioned to provide maximum coupling force at critical areas, reducing overall complexity while maintaining strength.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The coupling part extends partially along the arc box rather than covering the full length, providing sufficient coupling force for the application requirements without the excessive material usage and complexity of a full-length extension. This partial action approach achieves the necessary reliability with optimized resource utilization.

Inventive Principle:
Principle #16Partial or excessive action

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 ensures a stable coupling force between the arc cover and the frames, preventing separation even under impact from repeated arc extinguishing operations, thus enhancing the reliability and durability of the electromagnetic contactor.

Implementation Method 1

When a specified voltage is applied to the coil, an excitation current flows, to generate magnetic flux in the fixed core, which then turns into a magnet. Accordingly, the movable core is attracted toward the fixed core.

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4092709B1Electromagnetic contactor
Publication Date: 2025.05.28 LS ELECTRIC CO LTD
  • EP4092709B1 patent drawingFigure 1
  • EP4092709B1 patent drawingFigure 2
  • EP4092709B1 patent drawingFigure 3

AI summary

The present invention relates to a frame of an electromagnetic contactor, and more specifically, to an electromagnetic contactor having excellent coupling force between an arc box and a frame. The electromagnetic contactor, according to one embodiment of the present invention, comprises: a lower frame; an upper frame coupled to the upper portion of the lower frame; and an arc cover coupled to the upper portion of the upper frame, wherein a first coupling part, capable of fastening a fastening member, is protrudingly formed on one surface of the lower frame, a second coupling part, connected to the first coupling part and capable of fastening the fastening member, is protrudingly formed on one surface of the upper frame, and a third coupling part, connected to the second coupling part and capable of fastening the fastening member, is protrudingly formed on one surface of the arc cover, wherein the fastening member is fastened by connecting the first coupling part, the second coupling part and the third coupling part.