Contact Device Spring Load Adjustment Structure
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Solution Overview
Problem
The existing contact devices face challenges in downsizing while maintaining consistent spring load due to variability in initial contraction amounts of pressing springs, leading to inconsistent pressing forces, which necessitates stronger electromagnet blocks, increasing device size.
Innovation Solution
A spring load adjustment structure that includes a divided holding portion with an adjustment plate, allowing for easy welding and adjustment of the spring load by changing the distance between the bottom plate and the adjustment plate, ensuring consistent pressing force without increasing the device size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the pressing spring is downsized to reduce contact device size, then the contact device size decreases, but the pressing force decreases
Solution Approach 1:
The patent changes the spring constant parameter of the pressing spring to compensate for size reduction. By selecting a pressing spring with a higher spring constant, the pressing force is maintained even when the spring size is reduced, thus resolving the contradiction between downsizing and maintaining pressing force
2Force
If the spring constant of the pressing spring is increased to maintain pressing force during downsizing, then the pressing force is maintained, but the variability of initial pressing force increases
Solution Approach 1:
The patent performs preliminary adjustment of the pressing spring's contraction amount during assembly. By adjusting the initial contraction amount of the pressing spring before final assembly, the initial pressing force can be standardized across all contact devices, reducing variability and improving manufacturing precision
3Reliability
If the electromagnet block is strengthened to compensate for pressing force variability, then the pressing force consistency improves, but the contact device size increases
Solution Approach 1:
The patent adjusts the initial contraction amount of the pressing spring as a preliminary action during assembly, which standardizes the initial pressing force and reduces variability. This eliminates the need to strengthen the electromagnet block, thus maintaining pressing force consistency without increasing device size
4Manufacturing precision
If the initial contraction amount of the pressing spring is standardized to reduce variability, then the pressing force consistency improves, but the adjustment complexity increases
Solution Approach 1:
The patent incorporates an adjustment mechanism that allows the initial contraction amount of the pressing spring to be standardized during assembly. This preliminary adjustment action enables consistent initial pressing force across all devices while maintaining relatively simple adjustment procedures
Solution Approach 2:
The patent replaces complex mechanical adjustment mechanisms with a simpler adjustment method that involves modifying the initial contraction amount of the pressing spring. This substitution reduces adjustment complexity while achieving the goal of standardized initial pressing force
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 solution enables easy adjustment and consistent initial pressing force across contact devices, reducing variability and eliminating the need for larger electromagnet blocks, thus maintaining device compactness.
Implementation Method 1
a pressing spring that extends and contracts in a moving direction of the movable contacts so as to bias the movable contact maker toward the fixed contacts
Implementation Method 2
a coil spring is generally used as the pressing spring, and the coil spring is arranged in a state of being contracted by a predetermined length from the natural length
Implementation Method 3
a movable shaft is moved in the axial direction due to turning on/off energization of an electromagnet block
Implementation Method 4
the adjustment plate and each of the first and second side plates are subjected to resistance welding at a position at which pressing force of the pressing spring against the movable contact maker is a predetermined value
Data Source
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AI summary
A contact device includes: fixed terminals; a movable contact maker; a pressing spring; an adjustment plate that comes into contact with an upper face of the movable contact maker; a holding portion that has a bottom plate sandwiching the movable contact maker and the pressing spring with the adjustment plate, and side plates; a movable shaft; and an electromagnet block. The holding portion is divided into first and second holding portions that are separated from each other. The first and second holding portions are electrically connected to each other via only the adjustment plate, due to the adjustment plate being sandwiched by a first side plate of the first holding portion and a second side plate of the second holding portion. The adjustment plate is moved in extending and contracting directions of the pressing spring, and the adjustment plate and each of the first and second side plates are subjected to resistance welding at a position at which pressing force of the pressing spring is a predetermined value.