Diaphragm Valve End Positioning via Actuator Current Monitoring

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Diaphragm valves with actuators face issues due to varying production tolerances and mechanical end stop adjustments, leading to uneven wear and increased loads on the diaphragm, as well as the need for expensive pressure-sensitive membranes and additional sensors.

Innovation Solution

A method for determining the end positions of a diaphragm valve using drive current monitoring, allowing for precise positioning and compensation of tolerances, which includes initiating diaphragm displacement into predefined end positions, monitoring drive current values, and autonomously adjusting positions to ensure accurate operation and detect irregularities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the diaphragm valve uses mechanical end stops to define end positions, then the valve structure is simple, but the end positions cannot be precisely aligned due to production tolerances and manual assembly variations

Engineering Contradiction:
Improveend position alignmentVSAvoidpositioning system
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces the purely mechanical end stop positioning system with an electronic control system that uses drive current monitoring to detect and precisely align end positions. The controller monitors the drive current during actuator movement and identifies end positions based on current characteristics, eliminating the need for manual mechanical adjustment and achieving precise alignment despite production tolerances.

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

2Reliability

If the diaphragm valve operates with imprecise end position alignment, then the device complexity is low, but the diaphragm experiences higher stress and faster wear

Engineering Contradiction:
Improvediaphragm service lifeVSAvoidend position control system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a feedback mechanism where the controller continuously monitors the drive current during actuator operation. When the diaphragm reaches an end position, the drive current changes characteristically, providing feedback to the controller. This feedback allows the system to precisely identify and stop at the correct end positions, preventing excessive diaphragm stress and extending service life.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-adjustment by automatically detecting end positions through drive current monitoring and autonomously correcting position deviations. The controller compares the detected end position with the target position and automatically adjusts the actuator to achieve precise alignment, eliminating the need for manual intervention and ensuring consistent protective positioning.

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If pressure-sensitive membranes and additional sensors are used to improve positioning precision, then the end position alignment is accurate, but the manufacturing cost increases

Engineering Contradiction:
Improveend position precisionVSAvoidmanufacturing cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent extracts the positioning function from separate expensive components (pressure-sensitive membranes and additional sensors) and integrates it into the existing actuator's drive current monitoring capability. By utilizing the drive current that already flows through the actuator, the system achieves precise end position detection without adding separate sensing components, thereby reducing manufacturing costs.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent makes the drive current serve multiple functions: it both actuates the motor and provides positioning information. The same electrical signal that drives the actuator also contains information about the diaphragm's position, allowing the system to perform both actuation and sensing functions with a single component, eliminating the need for additional sensors and reducing overall system cost.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Reliability

If the diaphragm valve uses autonomous end position detection, then the operational reliability is improved, but the control system complexity increases

Engineering Contradiction:
Improveoperational reliabilityVSAvoidcontrol system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the end position detection function with the existing actuator control system. The controller that already manages actuator operation is extended to also monitor drive current characteristics for position detection. By combining actuation and positioning control in a single integrated controller, the system achieves autonomous operation without adding separate complex detection systems.

Inventive Principle:
Principle #5Merging (Combining)

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 method extends the service life of diaphragm valves by reducing wear, compensating for operational irregularities, and eliminating the need for additional sensors, thereby enhancing operational reliability and reducing manufacturing costs.

Implementation Method 1

setting the first end position is carried out by means of drive current monitoring, wherein the first end position is reached when a current value predefined for the actuator is reached

Methodology Applied
Scientific EffectDrive current monitoring:

Data Source

PatentEP3745009B1Commissioning of a diaphragm valve
Publication Date: 2023.07.05 GEORG FISCHER ROHRLEITUNGSSYSTEME AG
  • EP3745009B1 patent drawingFigure 1~3

AI summary

Method for determining the end positions of a diaphragm in a diaphragm valve with actuator: • Triggering the diaphragm movement to a first end position, • Determining the first end position of the diaphragm, wherein the determination of the first end position is carried out by means of actuator current monitoring, wherein the first end position is reached when a predefined current value is reached, • Storing the first end position, • Autonomously moving to a second end position of the diaphragm, preferably in the opposite direction, • Determining the second end position of the diaphragm, wherein the determination of the second end position is carried out by a predefined travel path (a) of the diaphragm starting from the first end position, • Storing the second end position.