Relay Contact Magnetic Shielding for Short-Circuit Hold and Arc Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-voltage DC relays face challenges with heat loss, anti-short circuit current capacity, and anti-short circuit voltage capacity, leading to contact bouncing and arcing due to electrodynamic repulsion forces, which existing solutions cannot adequately address within the constraints of small volume and low power consumption.
Innovation Solution
A magnetic shielding structure for relay contacts, comprising a movable contact piece, stationary contact lead-out terminals, anti-short circuit assembly, permanent magnets, and magnetic shielding members, which generate a suction force to resist electrodynamic repulsion and shield magnetic fields to prevent arcing and ensure reliable contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the coil size is increased to improve holding force, then the electrodynamic repulsion force resistance is improved, but the device volume increases and power consumption increases
Solution Approach 1:
The patent introduces a first magnetic shielding member as an intermediary component between the stationary contact lead-out terminal and the movable contact piece. This shielding member absorbs and redirects magnetic field lines, creating a magnetic barrier that enhances the effective holding force without requiring a larger coil. The magnetic shielding member acts as a mediator that optimizes magnetic field distribution, allowing the existing coil to generate sufficient holding force while maintaining compact dimensions.
Solution Approach 2:
The patent changes the magnetic field distribution parameters by introducing magnetic shielding members with specific permeability characteristics. By adjusting the magnetic field path and concentration through these shielding components, the holding force is enhanced without increasing coil size or power consumption. The shielding members modify the magnetic circuit parameters to achieve more efficient flux utilization.
2Force
If the contact pressure is increased to reduce contact resistance, then the electrodynamic repulsion force resistance is improved, but the device complexity and power consumption increase
Solution Approach 1:
The patent uses magnetic shielding members as intermediary components that indirectly enhance contact pressure effects. Rather than directly increasing mechanical contact pressure through complex spring mechanisms, the shielding members optimize the magnetic field to improve the magnetic holding force, which in turn maintains reliable contact. This approach achieves the desired contact force enhancement through magnetic field optimization rather than mechanical complexity.
3Device complexity
If no magnetic shielding is provided, then the device structure is simple, but magnetic field interference causes contact bouncing and arcing
Solution Approach 1:
The patent introduces magnetic shielding members as intermediary components that intervene in the magnetic field path between the stationary and movable contacts. These shielding members absorb and redirect magnetic field lines, preventing field interference that would cause contact bouncing and arcing. The shielding members act as mediators that maintain contact stability by controlling magnetic flux distribution without adding significant structural complexity.
Solution Approach 2:
The patent converts the potentially harmful magnetic field interference into a beneficial effect by using magnetic shielding members to redirect the magnetic flux. Instead of allowing the magnetic field to cause contact instability, the shielding members guide the flux to reinforce the holding force and stabilize the contact. The magnetic field that could have caused harm is transformed into a stabilizing influence through proper shielding and redirection.
4Force
If the coil ampere-turn value is increased to improve holding force, then the electrodynamic repulsion resistance is improved, but the power consumption increases
Solution Approach 1:
The patent changes the magnetic circuit parameters by introducing high-permeability magnetic shielding members that improve flux utilization efficiency. This allows the existing coil ampere-turns to generate sufficient holding force through optimized magnetic field distribution. The shielding members modify the magnetic reluctance and flux path, enabling the same electrical input to produce enhanced magnetic output without increasing power consumption.
Solution Approach 2:
The magnetic shielding members serve as intermediaries that amplify the effectiveness of the coil's magnetic field. By optimizing the magnetic circuit through these shielding components, the existing ampere-turns generate more effective holding force. The shielding members mediate between the electrical input and mechanical output, improving the conversion efficiency without requiring additional electrical power.
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 magnetic shielding structure effectively reduces electrodynamic repulsion forces, prevents explosions, and enhances safety and service life by maintaining reliable contact under high short-circuit currents, while optimizing the anti-short circuit effect.
Implementation Method 1
a permanent magnet, disposed around the contact assembly to achieve arc extinguishing by using a magnetic field formed by the permanent magnet
Implementation Method 2
the first magnetic shielding member is configured to absorb the magnetic field transmitted from the permanent magnet to the anti-short circuit assembly
Implementation Method 3
configured to generate suction force in the event of a faulty high current in the movable contact piece for resisting an electrodynamic repulsion force between the movable contact piece and the stationary contact lead-out terminals
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
A magnetic shielding structure for a relay contact and a relay are provided, the magnetic shielding structure includes a contact assembly (2), a first magnetic shielding member (5), an anti-short circuit assembly (3) and a permanent magnet (6). The contact assembly (2) includes a movable contact piece (22) and a pair of stationary contact lead-out terminals (21), and the movable contact piece (22) is used to contact with or separate from the pair of stationary contact lead-out terminals (21); the anti-short circuit assembly (3) is at least disposed at an upper side of the movable contact piece (22) along an axial direction of the stationary contact lead-out terminals (21), and can generate suction force when a faulty high current in the movable contact piece (22) for resisting an electrodynamic repulsion force between the movable contact piece (22) and the stationary contact lead-out terminals (21); the permanent magnet (6) is disposed around the contact assembly (2) to achieve arc extinguishing by a magnetic field formed by the permanent magnet (6); the first magnetic shielding member (5) is sleeved on the outside of a stationary contact lead-out terminal (21) for shielding a magnetic field generated by the stationary contact lead-out terminal (21) when energized; the first magnetic shielding member (5) blocks the magnetic field transmitted from the permanent magnet (6) to the anti-short circuit assembly (3).