Electromagnetic Relay Contact Layout Without a Return Spring
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Solution Overview
Problem
Existing electromagnetic relays have complex structures that can be improved for simplification.
Innovation Solution
The electromagnetic relay design includes a coil, bobbin, core, armature, first and second movable springs, and a card with a protruding portion that moves the second movable spring into or out of contact with the second fixed contact, eliminating the need for a separate return spring and allowing for increased contact pressure and reduced arc interference between contacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate return spring is added to move the second movable contact, then the contact switching function is improved, but the device complexity increases
Solution Approach 1:
The patent combines the return spring function with the first movable spring structure. The first movable spring serves dual purposes: it moves the first movable contact and simultaneously provides the return force for the second movable contact through its elastic deformation, eliminating the need for a separate return spring and reducing structural complexity.
Solution Approach 2:
The first movable spring is designed to perform multiple functions: it acts as the actuating element for the first contact device and simultaneously serves as the return mechanism for the second contact device. This multi-functional design reduces the total number of components while maintaining reliable contact switching.
2Volume of moving object
If the movable contacts are positioned closer together, then the device size is reduced, but electric arcs may interfere with each other
Solution Approach 1:
The patent positions the first and second movable contacts at different locations along the armature structure, utilizing the spatial dimension to separate their operational zones. The first movable contact is associated with one end of the armature while the second is associated with the other end, allowing compact overall dimensions while maintaining sufficient arc separation through strategic spatial arrangement.
3Reliability
If the contact pressure is increased to improve reliability, then the contact reliability is improved, but the force required to move the contacts increases
Solution Approach 1:
The movable springs are designed to generate their own contact pressure through their elastic properties. When the armature moves, the springs deform and automatically exert sufficient contact force on the fixed contacts without requiring additional actuating force. This self-generating contact pressure mechanism improves reliability while minimizing the force needed to initiate contact movement.
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 simplified structure enhances contact reliability and reduces the likelihood of electric arcs affecting each other, while maintaining efficient switching operations.
Implementation Method 1
The electromagnet generates electromagnetic force for driving the armature to move the movable terminal and the auxiliary movable terminal
Implementation Method 2
When the electromagnet stops generating electromagnetic force, the armature is returned to the original position by the return force of the return spring
Data Source
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AI summary
This electromagnetic relay includes: a coil; a bobbin on which the coil is wound; a core extending in the up-down direction and being inserted into the bobbin; an armature disposed above the core; a first fixed contact; a first movable spring including a first movable contact facing the first fixed contact and configured to cause the first movable contact to move into and out of contact with the first fixed contact; a second fixed contact; a second movable spring including a second movable contact facing the second fixed contact and configured to cause the second movable contact to move into and out of contact with the second fixed contact; and a card configured to cause the second movable contact to move into or out of contact with the second fixed contact according to switching of the coil between an excited state and a non-excited state. The first movable spring is fixed above the armature. The armature includes a first end and a second end. The first movable spring includes a first end portion that is near the first end of the armature and a second end portion that is farther from the first end of the armature than the first end portion. The first movable contact is disposed on the first end portion of the first movable spring. The card is disposed facing the second end of the armature.