Pressure-Relief Relay Structure for Sealed Contact Chamber Explosion Risk
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Solution Overview
Problem
High-voltage DC relays are prone to explosion due to the sealed contact cavity exploding under high short-circuit current or overload conditions, causing severe arcing and ignition between contacts.
Innovation Solution
A relay design incorporating a pressure relief valve assembly that includes a yoke plate with a pressure relief hole, which is closed under normal conditions and opens when gas pressure exceeds a threshold, allowing gas to be released to prevent cavity explosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the contact system is sealed by contact sealing cavities filled with gases under pressure to assist in extinguishing arcs, then arc extinguishing performance is improved, but the sealed cavity is prone to explode under high short-circuit current or overload conditions
Solution Approach 1:
The sealed cavity is segmented by introducing a pressure relief valve that divides the cavity into a pressurized sealing environment and an external atmosphere, allowing controlled pressure release to prevent catastrophic failure
Solution Approach 2:
The pressure relief valve is pre-configured with a breaking pressure threshold that activates before the cavity can explode, performing the protective action in advance of the potential failure condition
2Reliability
If the contact system is sealed to prevent arcing and ignition, then contact reliability is improved, but gas pressure buildup under short-circuit conditions causes cavity explosion
Solution Approach 1:
The pressure relief valve acts as an intermediary component between the sealed contact cavity and the external environment, mediating the gas pressure buildup by providing a controlled release path when pressure exceeds the threshold
Solution Approach 2:
The harmful excess gas pressure is extracted from the sealed cavity through the pressure relief valve, removing the dangerous accumulation before it can cause explosion
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 pressure relief valve assembly effectively manages gas pressure, preventing the contact chamber from exploding by releasing excess gas, thus ensuring the relay's operational safety and reliability.
Implementation Method 1
The pressure relief valve assembly is arranged on the first yoke plate and configured to close the pressure relief hole when a gas pressure in the contact chamber is less than a threshold and configured to be broken to open the pressure relief hole when the gas pressure in the contact chamber is greater than or equal to the threshold
Data Source
AI summary
A relay of the present disclosure includes an insulation cover, a first yoke plate, a contact assembly, a driving assembly and a pressure relief valve assembly. The first yoke plate is connected with the insulation cover and encloses a contact chamber with the insulation cover. The first yoke plate is provided with a pressure relief hole. The driving assembly is connected with the movable contact piece and configured to drive the movable contact piece move. The pressure relief valve assembly is arranged on the first yoke plate and configured to close the pressure relief hole when a gas pressure in the contact chamber is less than a threshold and configured to be broken to open the pressure relief hole when the gas pressure in the contact chamber is greater than or equal to the threshold.