Twisting Unit Self-Learning Tension Sensor Thread Breakage

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Solution Overview

Problem

Existing twisting machines lack an efficient and adaptive system for detecting thread breakage during the twisting process, leading to tangles and operational difficulties due to the reliance on manually set reference values and sensitive sensor installation positions.

Innovation Solution

A twisting unit equipped with a self-learning tension sensor that automatically sets reference values and detects thread breakages, using a piezoelectric sensor with a fork element to measure tension and control the cutting of yarn, allowing for adaptive operation and eliminating the need for manual input of tension values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a piezoelectric sensor is installed in direct proximity to the pigtail to monitor thread tension, then thread breakage can be detected, but the sensor installation position becomes extremely relevant and must be reasonably chosen a priori according to the expected tension of the thread

Engineering Contradiction:
Improvethread breakage detectionVSAvoidsensor installation position sensitivity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The control unit performs a self-learning phase during initial operation to automatically determine the optimal reference tension values for the specific yarn batch and machine configuration. This preliminary action eliminates the need for manual a priori setting of sensor thresholds and compensates for installation position variations, allowing the system to adapt to the actual operating conditions before production begins.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If manual entry of reference tension values is required in the machine PC based on yarn features, then tension monitoring can be performed, but the operating versatility of the machine is reduced and requires changes at each batch change

Engineering Contradiction:
Improvetension monitoringVSAvoidoperating versatility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The control unit automatically performs the self-learning phase to determine optimal reference tension values without requiring manual operator intervention. The system serves itself by autonomously adapting to different yarn batches and machine configurations, eliminating the need for operators to manually enter reference values and thereby maintaining operating versatility across different production scenarios.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If the contact pressure of the piezoelectric sensor is used to monitor thread tension, then tension variations due to breakage can be detected, but the response of the pressure sensor strongly depends on its installation position and the deviation imposed on the thread

Engineering Contradiction:
Improvetension measurementVSAvoidinstallation position sensitivity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system dynamically adjusts the reference tension values based on the actual operating conditions detected during the self-learning phase. By adapting the measurement parameters (reference tension thresholds) to the specific installation position and yarn characteristics, the system maintains measurement precision without requiring complex installation procedures or sensitive position-dependent setups.

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

The system effectively interrupts and resumes twisting based on detected thread breakages, reducing tangles and simplifying the mechanical and electronic architecture by using relative tension deviations, enhancing operational versatility and reducing operator intervention.

Implementation Method 1

the use of a piezoelectric sensor, commonly installed in direct proximity to the pigtail, provided with an open fork in ceramic material which receives a certain pressure in a transverse direction from the longitudinally running thread

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP4261331A1A twisting unit with a stand-alone thread breakage control sensor and a method for detecting the breakage of a thread being twisted
Publication Date: 2023.10.18 SAVIO MACCHINE TESSILI SPA
  • EP4261331A1 patent drawingFigure 1~2
  • EP4261331A1 patent drawingFigure 3
  • EP4261331A1 patent drawingFigure 4

AI summary

Twisting unit (4) of a yarn (8) consisting of at least two threads which are twisted comprising at least one pigtail (12) thread guide inside which the yarn (8) twists along a longitudinal direction (X-X), cutting means of the yarn (8) configured to cut the yarn (8) in the event of detection of a breakage of at least one thread forming the yarn (8), at least one device for detecting the breakage (16) of at least one of said threads forming the yarn (8), comprising a tension sensor (20) of said yarn (8), a processing and control unit (24) operatively connected to said tension sensor (20) of said yarn (8). Advantageously the processing and control unit (24) is programmed so that upon starting and/or restoring the twisting process, a self-learning step is performed in which a reference value (R) of the tension of the yarn (8) is stored, to be monitored during twisting; if, during twisting, the tension of the yarn (8) undergoes a percentage decrease, with respect to said reference value (R), greater than or equal to a predefined maximum percentage deviation, the twisting is interrupted.