Pipe Coupling Coil Spring Geometry to Prevent Valve Closure Failure
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Solution Overview
Problem
Conventional coil springs in pipe couplings can deform under high loads, causing the connecting portion to be pushed into the expanding-contracting portion, leading to failure in properly urging the valve element to the closed position when the pipe coupling is disconnected.
Innovation Solution
A coil spring design with a connecting portion that includes a first portion extending curvedly outward, a second portion extending inward through the valve support, a third portion curving to overlap the end winding, and a fourth portion extending inward to the support winding, preventing the connecting portion from entering the expanding-contracting portion, even under high compression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the coil spring is compressed to apply high load to the valve element, then the valve element can be reliably pressed to the closed position, but the connecting portion may be pushed into the expanding-contracting portion causing plastic deformation
Solution Approach 1:
The connecting portion is designed with a curved configuration that extends radially outward from the expanding-contracting portion, creating a geometric path that prevents the connecting portion from being pushed into the expanding-contracting portion during compression. This curved geometry inherently resists the inward radial force that would cause plastic deformation.
Solution Approach 2:
The connecting portion extends in a radial direction perpendicular to the axial compression direction, adding a dimensional constraint that prevents the connecting portion from entering the expanding-contracting portion. By utilizing radial extension rather than purely axial alignment, the design creates spatial separation that maintains structural integrity under load.
2Strength
If the connecting portion is designed to extend radially outward to prevent deformation, then the connecting portion maintains structural integrity under high load, but the outer diameter of the coil spring increases
Solution Approach 1:
The radial extension of the connecting portion is localized to specific regions where structural reinforcement is needed, rather than uniformly increasing the outer diameter throughout the entire coil spring. This allows the connecting portion to maintain integrity under high load while minimizing the overall volume increase of the moving object.
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 configuration ensures the valve support portion remains stable and prevents the coil spring from becoming deformed or caught, allowing the valve element to reliably return to the closed position after disconnection, even under excessive force.
Implementation Method 1
the expanding-contracting portion being wound a plurality of turns so as to expand and contract in the direction of the longitudinal axis when the valve element is displaced between the closed position and the open position
Implementation Method 2
When compressed, a coil spring usually expands slightly in the radial direction, resulting in an increase in the outer diameter
Data Source
AI summary
A coil spring is disposed in a fluid passage between a cylindrical body and a valve element to urge the valve element toward a closed position. The coil spring comprises a valve support portion supporting the valve element, a secured portion secured to an inner peripheral surface of the fluid passage, an expanding-contracting portion extending from the secured portion, and a connecting portion between the expanding-contracting portion and the valve support portion. The connecting portion comprises a first portion curved so as to pass radially outward of an end winding portion of the expanding-contracting portion, a second portion passing through the center of the valve support portion, a third portion extending curvedly so as to overlap the first portion, and a fourth portion extending to the valve support portion. When the coil spring is compressed, the valve support portion is supported to the expanding-contracting portion 54 through the connecting portion.