Arc Extinguishing Unit With Magnetic Arc Path and Magnet Protection

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Solution Overview

Problem

Existing air circuit breakers face challenges in effectively extinguishing arcs without using sulfur hexafluoride gas, and there is a lack of methods to form an arc path that does not involve guide plates, which can damage magnets and increase occupied space.

Innovation Solution

An arc extinguishing unit with a structure comprising support plates, a grid, a magnet case, and extinguishing magnets that form a magnetic field to quickly extinguish and move arcs, while minimizing space and protecting magnets from damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If guide plates are used to induce arc toward the grid, then arc induction is achieved, but magnets are damaged by arc and occupied space increases

Engineering Contradiction:
Improvemagnet protectionVSAvoidoccupied space
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent removes the guide plate component from the system and replaces it with a magnetic field-based arc induction mechanism. The magnet case with embedded magnets creates magnetic flux that directs the arc path toward the grid without physical contact, thereby protecting the magnets from arc damage while maintaining compact dimensions.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces magnetic flux as an intermediary field between the magnets and the arc. The magnetic field acts as a mediator to guide the arc path without requiring direct physical interaction between magnets and arc, thus protecting the magnets while achieving arc induction.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If magnets are exposed to form magnetic field for arc movement, then arc extinguishment is achieved, but magnets are damaged by arc

Engineering Contradiction:
Improvearc extinguishment speedVSAvoidmagnet durability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments the magnetic field generation function from the arc interaction function. Magnets are embedded within the magnet case structure, creating magnetic flux that extends through the grid assembly to influence arc movement without requiring magnet exposure to the arc environment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from direct spatial exposure of magnets to arc to indirect magnetic field interaction. The magnetic flux extends in the dimensional space between the magnets and arc, allowing arc extinguishment through field interaction rather than physical contact.

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

3Adaptability or versatility

If arc path is formed adjacent to guide plate, then arc induction works, but arc path formation is limited

Engineering Contradiction:
Improvearc path formation flexibilityVSAvoidstructure design
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The magnet case structure serves multiple functions: it houses the magnets, provides structural support for the grid assembly, and generates the magnetic field for arc induction. This multi-functional design eliminates the need for separate guide plates while maintaining arc path formation capability.

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

Solution Approach 2:

The patent merges the magnet housing structure with the arc induction function. The magnet case and grid assembly are integrated into a unified structure where the magnetic field generation and arc path guidance are combined, reducing overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

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 allows for rapid arc extinguishment and movement without excessive design changes, protecting magnets and maintaining a compact structure, while effectively forming an arc path for discharge.

Implementation Method 1

an extinguishing magnet which forms a magnetic field between the plurality of support plates

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Data Source

PatentEP4120303B1Arc extinguishing unit and air circuit breaker comprising same
Publication Date: 2025.09.10 LS ELECTRIC CO LTD
  • EP4120303B1 patent drawingFigure 1
  • EP4120303B1 patent drawingFigure 2
  • EP4120303B1 patent drawingFigure 3

AI summary

Disclosed are an arc extinguishing unit and an air circuit breaker comprising same. An arc extinguishing unit, according to an embodiment of the present invention, comprises an extinguishing magnet unit that forms a magnetic field inside the arc extinguishing unit. Accordingly, a generated arc receives an electromagnetic force in the direction facing the exterior of the air circuit breaker, and thus can be rapidly moved and extinguished. The extinguishing magnet unit is accommodated in a magnet case. The magnet case can seal the extinguishing magnet unit. Therefore, the extinguishing magnet unit is not damaged by the generated arc.