DC Relay Noise Reduction via Elastic Cushioning
Solution Overview
Problem
Conventional direct current relays generate noise due to collisions between the moving core and fixed core during 'ON' operations and between the shaft and middle plates during 'OFF' operations, degrading relay quality.
Innovation Solution
A direct current relay design featuring a fixed core inserted into a middle plate with a gap to reduce collisions, a straight-shaped shaft without intermediate protrusions to avoid collisions with middle plates, and tension springs to maintain contact pressure, utilizing compression and tension coil springs to balance forces and absorb impacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the moving core is made to contact the fixed core directly during 'ON' operation, then the switching action is reliable, but noise is generated due to collision impact
Solution Approach 1:
The patent applies beforehand cushioning by installing an elastic member (such as a rubber or spring element) between the moving core and the fixed core. This elastic member is pre-positioned to absorb the impact when the moving core contacts the fixed core during switching operations, thereby cushioning the collision before it generates noise. The elastic member deforms under impact and then returns to its original shape, eliminating the sharp collision sound while maintaining reliable switching contact.
2Stability of the object's composition
If the shaft is designed with intermediate protrusions to engage with middle plates, then the structural stability is improved, but noise is generated due to collision between shaft and middle plates during 'OFF' operation
Solution Approach 1:
The patent applies beforehand cushioning by providing an elastic member at the lower end of the shaft that contacts the middle plate. This elastic member is pre-positioned to absorb the impact when the shaft contacts the middle plate during OFF operation. The elastic member deforms under the impact force and then rebounds, cushioning the collision before it generates noise, while the shaft's intermediate protrusions maintain structural stability through proper engagement with the middle plate.
3Manufacturing precision
If the fixed core is rigidly fixed to the middle plate, then the manufacturing precision is improved, but the impact during 'ON' operation cannot be attenuated
Solution Approach 1:
The patent applies beforehand cushioning by installing an elastic member between the fixed core and the middle plate. The elastic member is pre-positioned in a recess or groove of the middle plate, allowing the fixed core to be positioned with manufacturing precision while the elastic member remains free to deform and absorb impact during operation. This arrangement maintains the precise assembly alignment achieved during manufacturing while enabling impact attenuation during switching operations.
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 design effectively attenuates noise during both 'ON' and 'OFF' operations while maintaining contact pressure, enhancing the reliability and quality of the relay.
Implementation Method 1
If a current is applied to the coil 5 in an interrupted state shown in FIG. 1, a magnetic field is generated around the coil 5, and the fixed core 6 is magnetized within the magnetic field.
Implementation Method 2
a return spring 9 installed between the fixed core 6 and the moving core 7, and configured to return the moving core 7 to a direction which becomes far from the fixed core 6
Data Source
Figure 1
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AI summary
The present invention relates to a relay, and more particularly, to a direct current relay capable of reducing noise by attenuating an impact generated between a fixed core and a moving core during an 'ON' operation, and by attenuating an impact generated between a shaft and a middle plate during an 'OFF' operation. The direct current relay includes: a pair of fixed contacts fixedly-installed at one side of a frame; a movable contact installed below the pair of fixed contacts so as to be linearly moveable, and moveable to contact or to be separated from the pair of fixed contacts; a middle plate installed below the movable contact; a contact spring provided between the movable contact and the middle plate; a fixed core installed at the middle plate, and having a center through which a shaft hole passes; a moving core installed below the fixed core so as to be linearly moveable; a shaft having an upper end where a mounting portion protruding to an upper side of the movable contact is formed, and having a lower end coupled to the movable core; and a tension spring installed between the movable contact and the mounting portion.