Pipe Coupling Rotary Valve Cam Mechanism Friction Reduction

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Solution Overview

Problem

The existing pipe coupling designs face issues with increased frictional force between the rotary valve member and the valve seat, which can stop the rotation of the rotary valve member when returning to the closed position, necessitating higher spring urging force but limited by the need to move the valve unit backward during coupling.

Innovation Solution

The pipe coupling incorporates a cam mechanism and a tubular valve support structure with tapered surfaces to facilitate the rotation of the rotary valve member, allowing it to return to the closed position even with increased pressing force, by reducing frictional force through axial movement and alignment of valve components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the pressing force between the rotary valve member and valve seat is increased to ensure sealing, then sealing reliability is improved, but frictional force increases and may stop the rotation of the rotary valve member when returning to the closed position

Engineering Contradiction:
Improvesealing reliabilityVSAvoidrotation of rotary valve member
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies dynamics by making the pressing force variable rather than constant. The urging means (spring) provides dynamic adjustment of the pressing force between the rotary valve member and valve seat, allowing sufficient sealing force when needed while reducing resistance during rotation operations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent segments the valve structure into distinct components: the rotary valve member, the valve seat, and the urging means. This segmentation allows the pressing force to be applied only where needed for sealing while keeping the rotation path relatively free from excessive friction.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the urging force of the spring member is increased to prevent the rotary valve member from stopping during rotation, then rotation reliability is improved, but the valve unit cannot be moved backward when coupling members are coupled

Engineering Contradiction:
Improverotation return reliabilityVSAvoidvalve unit movement during coupling
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent changes the parameter of spring force to an optimal value that satisfies both requirements: sufficient to ensure the rotary valve member returns to the closed position reliably, but not so strong as to prevent the valve unit from being moved backward during coupling operations.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces a purely mechanical constant-force system with a spring-based elastic force system, which provides automatic adjustment of the urging force based on the operational state, resolving the contradiction between rotation reliability and coupling operation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If the seal surface friction is increased to maintain sealing engagement, then sealing efficiency is improved, but the rotary valve member rotation is hindered

Engineering Contradiction:
Improvesealing efficiencyVSAvoidfrictional force
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The patent applies local quality by providing sealing surfaces with specific properties at the contact interface between the rotary valve member and valve seat. The seal surface is designed with appropriate roughness and material properties to maintain sealing efficiency while controlling friction during rotation.

Inventive Principle:
Principle #3Local quality

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

Ensures the rotary valve member can reliably return to the closed position during decoupling, maintaining sealing efficiency despite increased pressing force, by utilizing a cam mechanism and tapered surfaces to overcome frictional constraints.

Implementation Method 1

the valve unit is urged axially forward by a spring member toward a closed position for closing the fluid path

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

the seal surface sealingly engages all around a valve seat formed to surround the fluid path, thereby closing the fluid path

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2023028B1Pipe joint
Publication Date: 2015.07.15 NITTO KOHKI CO LTD
  • EP2023028B1 patent drawingFigure 1a
  • EP2023028B1 patent drawingFigure 1b
  • EP2023028B1 patent drawingFigure 1c

AI summary

A pipe coupling member has a tubular body (20) and a valve unit (22) slidably set in the through-hole of the tubular body. The valve unit has a valve holder (26) and a rotary valve member (30) supported by the valve holder so as to be rotatable about a pivot axis perpendicular to the axis of the through-hole. The valve holder comprises a valve seat portion (26-1) and a valve support portion (26-2) that are separately disposed in series in the axial direction or the direction of the axis of the though hole. The valve support portion rotatably supports the rotary valve member. When the valve holder moves axially in the through-hole, the rotary valve member is rotated by a cam mechanism (32) and displaced between a closed rotational position and an open rotational position while its spherical outer peripheral surface sliding relative to an annular valve seat of the valve seat portion. When in the closed rotational position, the rotary valve member sealingly engages all around the annular valve seat to close the fluid path. A spring member (28) urges the valve support portion to urge the valve holder toward the closed rotational position. When the coupling member is decoupled, the rotary valve member therein is surely placed in the closed rotational position.