Self-Medium Control Valve Pilot Line Descaling Mechanism

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Solution Overview

Problem

Existing self-medium-controlled control valves face operational reliability issues due to clogging of the pilot line with impurities like limescale deposits, which are inadequately removed by existing cleaning methods.

Innovation Solution

A cleaning wire element with an actuation contour that slides and applies a transverse force to scrape off limescale deposits, combined with a helical compression spring for enhanced operational safety and a sealing surface design to prevent leaks and limescale adhesion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a fixed cleaning wire element with hole clearance is used to clean the pilot line, then the cleaning mechanism is simple, but the cleaning effectiveness is insufficient due to inadequate removal of limescale deposits

Engineering Contradiction:
Improvecleaning mechanism simplicityVSAvoidcleaning effectiveness
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The cleaning wire element is made movable relative to the pilot line by coupling it to the adjustable main valve piston. When the piston stroke is adjusted, the cleaning wire moves through the pilot line, dynamically enabling effective cleaning action rather than relying on a fixed positioning system.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The cleaning function is integrated into the existing valve adjustment mechanism. The main valve piston's stroke adjustment motion automatically drives the cleaning wire through the pilot line, making the system self-cleaning without requiring separate cleaning mechanisms or additional energy input.

Inventive Principle:
Principle #25Self-service

2Device complexity

If the cleaning wire element is guided through the pilot line without contact, then the cleaning wire structure is simple, but the limescale deposits on the inner circumference cannot be removed effectively

Engineering Contradiction:
Improvecleaning wire guidance structureVSAvoiddeposit removal capability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The cleaning wire element is designed to strike against the inner circumference of the pilot line during piston adjustment, creating mechanical impact and vibration that effectively dislodges and removes limescale deposits adhering to the pipe walls.

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The piston adjustment motion, which is a necessary operational function of the valve, is converted into a beneficial cleaning action. The same movement that adjusts valve performance also drives the cleaning wire to remove deposits, turning a routine operational movement into a maintenance benefit.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 effectively increases operational reliability by efficiently removing limescale deposits and ensuring reliable sealing and operation even at low water pressures, preventing overloading and maintaining a permanent sealing function.

Implementation Method 1

The wire-side actuating contour and the piston-side counter-contour are geometrically designed to slide along each other, building up a transverse force acting on the wire element. The application of the transverse force allows the wire element to strike the inner circumference of the pilot line, which can scrape off any limescale deposits that may be present.

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

The application of the transverse force allows the wire element to strike the inner circumference of the pilot line, which can scrape off any limescale deposits that may be present.

Methodology Applied
Scientific EffectAbrasion: Abrasion

Implementation Method 3

a sealing surface design to prevent leaks and limescale adhesion

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 4

Due to the water pressure in the inlet chamber, the main valve piston can be moved in an opening direction.

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP3936748B1Control valve controlled by its own medium
Publication Date: 2024.05.15 GROHE AG
  • EP3936748B1 patent drawingFigure 1
  • EP3936748B1 patent drawingFigure 2~3
  • EP3936748B1 patent drawingFigure 4

AI summary

The invention relates to a self-medium-controlled control valve for liquid flow control, comprising a main valve with an axially adjustable main valve piston (21) and a cooperating main valve seat (23) which radially defines an outlet chamber (15) on the inside and an inlet chamber (13) on the outside, and a pilot valve for controlling the main valve piston (21), which has a control chamber (5) on the side of the main valve piston (21) facing away from the main valve seat (23), which is fluidically connected to the inlet chamber (13) via a pilot line (1) in the main valve piston (21) and to the outlet chamber (15) via a pressure relief line (31), and a pilot valve piston (33) which, in a closed position, closes the pressure relief line (31), thereby building up a closing pressure in the control chamber (5) and adjusting the stroke of the main valve piston (21) in a closing direction.and in an open position, the pressure relief line (31) opens, thereby equalizing the pressure between the control chamber (5) and the drain chamber (15) and adjusting the stroke of the main valve piston (21) in an opening direction, wherein an axially stationary cleaning wire element (3) with a hole clearance is guided through the pilot line (1), and when the main valve piston (21) is adjusted, the pilot line (1) is movable along the cleaning wire element (3) guided therein. According to the invention, the cleaning wire element (3) has an actuating contour (45) which, at least during the stroke adjustment, can be brought into contact with a counter contour (51) formed on the main valve piston (21) by generating a transverse force (F) acting on the cleaning wire element (3).