Relay Contact Pressure via Lorentz Force Extensions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing relays face a decrease in contact pressure between contacts due to electromagnetic repulsive forces when an overcurrent is applied, as the current tends to flow through the shortest path, resulting in reduced contact pressure at the end portions of C-shaped portions in previous designs.
Innovation Solution
The relay design includes extensions and external connections that ensure a larger section for current flow in opposite directions, increasing the electromagnetic repulsive force on the movable touch piece, and arranging these extensions symmetrically to equally act on the movable touch piece, thereby enhancing contact pressure between the movable and fixed contacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If C-shaped portions are added to fixed touch pieces to generate electromagnetic repulsive force, then contact pressure is improved, but current flows through the shortest path and does not reach the end portions, reducing the effectiveness of the electromagnetic repulsive force
Solution Approach 1:
The patent extends the C-shaped portions in the longitudinal direction to create a larger effective area for electromagnetic repulsive force generation. By adding extensions (first extension and second extension) that protrude from the fixed touch pieces, the current path is extended in the longitudinal dimension, allowing current to flow through a larger section and generate electromagnetic repulsive force more effectively along the entire length of the movable touch piece, not just at peripheral portions.
2Force
If extensions are added to increase the section for current flow, then electromagnetic repulsive force is increased, but device complexity increases
Solution Approach 1:
The extensions (first extension and second extension) are integrated with the fixed touch pieces as integral structures. The first extension protrudes from the first fixed touch piece and the second extension protrudes from the second fixed touch piece, forming a unified current-conducting structure. This merging approach increases the effective section for current flow and electromagnetic repulsive force generation without requiring separate additional components, thereby minimizing the increase in device complexity.
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
This design effectively prevents a decrease in contact pressure by increasing the electromagnetic repulsive force, ensuring stable contact between the movable and fixed contacts even under overcurrent conditions, and facilitates easy connection to external circuits with protruding connections in opposite directions.
Implementation Method 1
an electromagnetic repulsive force due to the Lorentz force is generated in the movable contact and the fixed contact by a current flowing through the movable contact and the fixed contact
Implementation Method 2
the first fixed touch piece 102 and the movable touch piece 101 have a section in which the directions of the current I are reversed. In this section, electromagnetic repulsive forces in directions repelling each other are generated by the Lorentz force
Data Source
AI summary
A relay has a case, a first fixed terminal including a first fixed contact, a second fixed terminal including a second fixed contact, a movable touch piece including a first movable contact that is disposed facing the first fixed contact and a second movable contact that is disposed facing the second fixed contact, the movable touch piece being disposed in the case and disposed so as to be movable in a contact direction in which the first movable contact and the second movable contact come into contact with the first fixed contact and the second fixed contact and a separation direction in which the first movable contact and the second movable contact separate from the first fixed contact and the second fixed contact. The first fixed terminal includes a first contact support configured to support the first fixed contact.