Air-Jet Loom Weft Control via Inlet Sensor Timing

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Solution Overview

Problem

Conventional air-jet looms fail to accurately control weft-insertion conditions due to a discrepancy between the unwinding timing of the weft yarn and the arrival timing of its leading end at the weft yarn passage, leading to unsuitable weft insertion.

Innovation Solution

An air-jet loom with a weft-insertion control apparatus that includes an inlet sensor to detect the arrival timing of the weft yarn's leading end at the weft yarn passage and a control device to adjust weft-insertion conditions, such as releasing timing and air-injection timing, based on this detection to ensure precise control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If weft-insertion start timing is calculated from unwinding timing of the weft yarn, then control can be performed based on available detection signals, but the control accuracy deteriorates due to time difference variation between unwinding timing and leading end arrival timing

Engineering Contradiction:
Improvetiming detection accuracyVSAvoidtime difference between unwinding timing and leading end arrival timing
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces the mechanical timing calculation method (based on unwinding timing) with an optical detection system (inlet sensor) that directly measures the arrival timing of the weft yarn leading end at the weft yarn passage inlet, eliminating the time difference error

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

Solution Approach 2:

The patent introduces an inlet sensor as an intermediary detection device positioned at the weft yarn passage inlet to directly detect the leading end arrival timing, serving as a mediator between the weft yarn and the control system to provide accurate timing information

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If weft-insertion conditions are controlled based on unwinding timing, then control can be implemented with existing detection systems, but the weft insertion quality deteriorates due to inaccurate timing control

Engineering Contradiction:
Improveweft insertion qualityVSAvoidtiming control precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent implements a feedback control system where the inlet sensor detects the actual leading end arrival timing and feeds this information back to the control device, which then adjusts the weft-insertion conditions based on the detected timing to ensure high-quality weft insertion

Inventive Principle:
Principle #23Feedback

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 accurately detects the inlet arrival timing of the weft yarn and suitably controls weft-insertion conditions, improving the quality of fabric production by ensuring timely and efficient weft insertion, reducing the likelihood of errors and energy consumption.

Implementation Method 1

an inlet sensor (180) that detects inlet arrival timing of a leading end of the weft yarn (Y) to arrive at an inlet (153in) of the weft yarn passage (153)

Methodology Applied
Scientific EffectOptical detection: Photoelectric Effect

Implementation Method 2

The air-jet loom is configured to insert a weft yarn (Y) through a weft yarn passage (153) by injecting air from a main nozzle (142) and a sub-nozzle (160)

Methodology Applied
Scientific EffectCompressed air injection: Pressure Gradient

Data Source

PatentEP4019678B1Air-jet loom with weft-insertion control apparatus
Publication Date: 2023.08.09 TOYOTA INDUSTRIES CORP
  • EP4019678B1 patent drawingFigure 1
  • EP4019678B1 patent drawingFigure 2
  • EP4019678B1 patent drawingFigure 3

AI summary

There is provided an air-jet loom with a weft-insertion control apparatus (110, 180). The air-jet loom is configured to insert a weft yarn (Y) through a weft yarn passage (153) by injecting air from a main nozzle (142) and a sub-nozzle (160, 160A to 160F). The weft-insertion control apparatus (110, 180) is configured to control weft insertion of the air-jet loom. The weft-insertion control apparatus (110, 180) includes an inlet sensor (180) configured to detect inlet arrival timing (Tin) of a leading end of the weft yarn (Y) to arrive at an inlet (153in) of the weft yarn passage (153), and a control device (110) configured to control a weft-insertion condition for inserting the weft yarn (Y) based on the inlet arrival timing (Tin). A detection range (180d) of the inlet sensor (180) includes the inlet (153in) of the weft yarn passage (153).