Pneumatic Handling Valve Timing for Quiet Precise Positioning

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Solution Overview

Problem

Existing handling devices face challenges in positioning actuators effectively and reliably with high stress and noise levels due to differing piston areas and the need for closed control loops.

Innovation Solution

A handling device with a selection of switching valve positions and an electromagnetically actuable, normally closed switching valve, connected on both sides of the piston, allows for precise positioning with reduced stress and noise, using a control device to specify switching times for the valves.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a closed control loop is used to position the piston, then positioning precision is improved, but stress and noise levels increase

Engineering Contradiction:
Improvepositioning precisionVSAvoidstress and noise
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The switching valve is activated in advance at a predetermined switching time before the piston reaches the target position. This preliminary action allows the piston to coast to the target position using its own momentum and the elastic storage element, rather than requiring continuous active control, thereby reducing stress and noise while maintaining positioning accuracy

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control system uses periodic switching of the switching valve based on predetermined switching times rather than continuous adjustment. This periodic action reduces the frequency of active interventions, lowering stress and noise generation while achieving accurate positioning through timed valve activation

Inventive Principle:
Principle #19Periodic action

2Force

If differing piston areas are used, then force balance is improved, but positioning reliability deteriorates

Engineering Contradiction:
Improveforce balanceVSAvoidpositioning reliability
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

An elastic storage element (spring) is introduced as an intermediary between the piston and the target position. This spring compensates for the effects of differing piston areas by providing a restoring force that helps return the piston to its initial position, thereby improving positioning reliability without requiring equal piston areas

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the physical state parameters by using compression or expansion of the elastic storage element to compensate for pressure differences caused by unequal piston areas. This allows reliable positioning to be achieved through parameter changes in the spring compression rather than through active control adjustments

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If active positioning control is used, then positioning accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidcontrol system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The piston system serves itself by using the elastic storage element to automatically return the piston to its initial position after the switching valve closes. This self-service mechanism eliminates the need for complex active positioning control systems, sensors, and continuous adjustment mechanisms, thereby reducing device complexity while maintaining positioning accuracy

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention extracts and eliminates the complex continuous control loop from the system, replacing it with a simple timed switching valve activation. By removing the need for continuous sensing and adjustment, the system achieves positioning accuracy with significantly reduced control system complexity

Inventive Principle:
Principle #2Taking out (Extraction)

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

Enables effective, process-reliable positioning with reduced stress and low noise levels, maintaining positions during power failure and allowing for leak testing, while avoiding the need for closed control circuits.

Implementation Method 1

connecting the cylinder to the pressure source or venting it

Methodology Applied
Scientific EffectPneumatic pressure: Pressure Increase

Implementation Method 2

The piston drive includes either a spring that biases the piston in one direction within the cylinder

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 3

switching valve which is electromagnetically actuable and designed as a normally closed valve

Methodology Applied
Scientific EffectElectromagnetic actuation: Electromagnet

Data Source

PatentEP3378608B1Pneumatically operated handling device with switching valve.
Publication Date: 2022.05.18 SCHUNK GMBH & CO KG
  • EP3378608B1 patent drawingFigure 1
  • EP3378608B1 patent drawingFigure 2

AI summary

A handling device such as a linear, gripping, clamping, rotary or swiveling device, comprising a base housing (100), at least one actuator movably arranged in the base housing (100), an axially extending cylinder and a piston coupled to the actuator and axially movably arranged in the cylinder, wherein a valve (106) is arranged which is connected to the cylinder on one side of the piston, wherein either a pressure source or a reference pressure source, in particular atmospheric pressure, can be connected to the cylinder through the valve (106) to influence an axial position of the piston, characterized in that a switching valve (110) for selectively opening or closing the connection is arranged in a connection between the valve (106) and the cylinder.