Valve Device Pressure-Based Flow Control

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Solution Overview

Problem

Existing methods for operating valve devices to supply compressed air to consumers are inefficient due to reliance on expensive position measurement systems and complex mass flow sensors, which increase the complexity and cost of controlling fluid flow.

Innovation Solution

A method that determines fluid pressures in different sections of a valve arrangement's fluid channel, calculates a flow value using a flow function, and provides actuation energy to set predefinable fluid volume or mass flows, eliminating the need for position measurement systems and mass flow sensors by using pressure sensors to directly control the valve element.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If displacement measuring systems and mass flow sensors are used to control compressed air supply, then control precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improvecontrol precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the complex displacement measuring systems and mass flow sensors from the control system. Instead, it uses only pressure sensors to determine fluid pressures in different sections of the fluid channel, which significantly reduces device complexity while maintaining control precision through direct pressure-based flow calculation

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces mechanical displacement measurement systems with a pressure-based control system. By using pressure sensors and calculating flow rates from pressure differences and valve element characteristics, the system substitutes complex mechanical measurement infrastructure with a simpler pressure-based approach that achieves equivalent or better control precision

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

2Measurement precision

If displacement measuring systems and mass flow sensors are used to control compressed air supply, then control precision is improved, but cost increases

Engineering Contradiction:
Improvecontrol precisionVSAvoidcost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent employs inexpensive pressure sensors instead of expensive displacement measuring systems and mass flow sensors. Pressure sensors are significantly cheaper and more readily available, reducing the overall system cost while maintaining adequate measurement precision for controlling compressed air supply to pneumatic consumers

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Device complexity

If pressure sensors are used instead of displacement measuring systems, then device complexity is reduced, but measurement precision may deteriorate

Engineering Contradiction:
Improvedevice complexityVSAvoidmeasurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements a feedback control mechanism where pressure sensors continuously monitor fluid pressures in different sections of the fluid channel. The control unit calculates the required valve element position based on pressure differences and desired flow rates, then adjusts the valve element accordingly. This closed-loop feedback ensures measurement precision is maintained despite using simpler pressure sensors instead of complex displacement measuring systems

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the measurement parameter from direct displacement measurement to pressure measurement. By measuring pressure differences across the valve element and using the known flow characteristics of the valve, the system indirectly determines flow rates with sufficient precision. This parameter change simplifies the measurement system while maintaining adequate control accuracy for pneumatic consumer applications

Inventive Principle:
Principle #35Parameter changes

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 approach reduces calculation effort and metrological requirements, allowing precise control of compressed air supply to compressed air consumers like pneumatic cylinders, while minimizing the need for expensive sensors and complex electrical connections, thus enhancing efficiency and reducing costs.

Implementation Method 1

determining a first fluid pressure in a first section of a fluid channel of the valve arrangement, which extends between an inlet port for a fluidically communicating connection with a fluid source or fluid sink and a valve element; determining a second fluid pressure in a second section of the fluid channel of the valve arrangement, which extends between the valve element and an outlet port for a fluidically communicating connection with a compressed air consumer

Methodology Applied
Scientific EffectPressure measurement:

Implementation Method 2

determining a flow rate for the valve element from the two fluid pressures and a flow function; providing the actuation energy to the actuating device to adjust the predefinable fluid volumetric flow rate or fluid mass flow rate

Methodology Applied
Scientific EffectFluid flow control through pressure differential: Pressure Gradient

Data Source

PatentEP3445976B1Method for operating a valve device, valve device and data carrier with a computer program
Publication Date: 2020.09.23 FESTO AG & CO KG
  • EP3445976B1 patent drawingFigure 1
  • EP3445976B1 patent drawingFigure 2~3

AI summary

The invention relates to a method for operating a valve device for supplying compressed air to a compressed air consumer (3; 63), comprising the steps: determining a first fluid pressure in a first section (20, 21, 22, 23) of a fluid duct of the valve assembly, which fluid duct extends between an input connection (28, 30) for a fluidically communicating connection to a fluid source (32; 66; 96) or fluid sink (33; 68) and a valve element (4, 5, 6, 7; 69; 99), determining a second fluid pressure in a second section (24, 25, 26, 27) of the fluid duct of the valve assembly, which fluid duct extends between the valve element (4, 5, 6, 7; 69; 99) and an output connection (29, 31) for a fluidically communicating connection to a compressed air consumer (3; 63), determining a through-flow value for the valve element (4, 5, 6, 7; 69; 99) from the two fluid pressures and a through-flow function, linking the through-flow value to a predefinable fluid volume flow or fluid mass flow for the pressurised fluid, which is provided to flow through the fluid duct (20 to 27), to form a guide value and determining a required amount of activation energy for an activation device (8, 9, 10, 11; 70, 71; 100, 101) which is designed to activate the valve element (4, 5, 6, 7; 69; 99) and providing the amount of activation energy to the activation device (8, 9, 10, 11; 70, 71; 100, 101) to set the predefinable fluid volume flow or fluid volume mass.