DC Circuit Breaker Shutter Mechanism for Compact Arc Extinction
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Solution Overview
Problem
Existing DC circuit breakers for high-voltage applications are difficult to downsize while maintaining reliable arc extinction and assembly efficiency, leading to challenges in compact installations and reduced productivity.
Innovation Solution
A DC circuit breaker design featuring a thermally responsive mechanism with a moving block, latch, and shutter system, utilizing insulative materials and biasing members to separate contacts and insert an insulating shutter for arc extinction, allowing for compact size and improved assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the contacts are separated by a sufficient distance or an arc extinguisher is provided to disperse the generated arc, then arc extinction is reliable, but the size of the circuit breaker increases
Solution Approach 1:
The shutter is inserted into the space between the fixed contacts and movable contacts, nesting the arc extinguishing component within the existing contact structure. This eliminates the need for additional external arc extinguishers and reduces the overall breaker size while maintaining reliable arc extinction
Solution Approach 2:
Instead of separating contacts in only one dimension (requiring large distance), the invention introduces a new dimension by inserting the shutter vertically between the contacts. This multi-dimensional approach allows for shorter contact separation distance while still achieving reliable arc extinction
2Volume of moving object
If the components of the circuit breaker are made smaller for downsizing, then the circuit breaker size is reduced, but assembly productivity decreases
Solution Approach 1:
The latch mechanism is integrated directly into the moving block structure, merging two separate components into one. This reduces the total number of parts to assemble while maintaining the necessary locking function, thereby improving assembly productivity despite the compact size
Solution Approach 2:
The moving block serves multiple functions: it houses the latch mechanism, guides the shutter movement, and provides the groove for bypass plate insertion. This multi-functionality reduces the number of separate components needed, simplifying assembly and improving productivity
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 design effectively cuts off high-voltage DC current, ensures reliable arc extinction, and enhances productivity by enabling a compact, efficient assembly process.
Implementation Method 1
a thermally responsive member provided in a position opposing an installation surface and configured to deform when the installation surface becomes equal to or greater than a prescribed temperature
Implementation Method 2
a shutter formed of an electrically insulative material and configured to be inserted between the fixed contacts and the movable contacts when the movable contacts are separated from the fixed contacts
Data Source
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AI summary
A DC circuit breaker (10) provided with a case (20); two fixed contacts (33); two movable contacts (42); a bypass plate (41) electrically connecting the two movable contacts; a moving block (43) configured to move the bypass plate; a moving block biasing member (434) configured to constantly bias the moving block in a direction to move away from the fixed contacts; a thermally responsive member (61) provided in a position opposing an installation surface and configured to deform when the installation surface becomes equal to or greater than a prescribed temperature; a latch (51) having a locking portion configured to restrict movement of the moving block by locking the moving block when the thermally responsive member is in a pre-deformation state, the latch being configured to operate to cancel the restriction of the movement of the moving block by unlocking the locking portion from the moving block in response to a deformation of the thermally responsive member; a shutter (73) configured to be inserted between the fixed contacts and the movable contacts when the movable contacts are separated from the fixed contacts; and a shutter biasing member (72) configured to constantly bias the shutter in a direction to be inserted between the fixed contacts and the movable contacts.