Air Jet Loom Sub-Nozzle Ejection Period Control
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Solution Overview
Problem
Existing methods for setting ejection periods in air jet looms fail to sufficiently reduce air ejection amounts while maintaining weft insertion stability, as they are limited by the need to prevent weft yarn slacking and defects in woven cloth.
Innovation Solution
The method involves dividing sub-nozzle groups into downstream, upstream, and intermediate sets, allowing for customizable air-ejection-amount reducing patterns that adjust ejection end times based on predetermined patterns, enabling flexible reduction of ejection periods across these groups to minimize air ejection while ensuring stable weft insertion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the ejection periods of sub-nozzle groups are increased to simplify control and ensure weft insertion stability, then the weft insertion stability is improved, but the air ejection amounts increase leading to higher energy consumption
Solution Approach 1:
The sub-nozzle groups are divided into three distinct sets (downstream, intermediate, upstream) with different ejection period settings. Each set can be independently controlled with customized reduction patterns, allowing differential energy optimization while maintaining overall weft insertion stability through coordinated operation of all sets
Solution Approach 2:
Different ejection period reduction patterns are applied to different spatial locations of sub-nozzle groups. The downstream set near the weft arrival side uses one pattern, the intermediate set uses another, and the upstream set uses a third pattern, optimizing air ejection locally in each region while maintaining global system stability
2Use of energy by moving object
If the ejection periods are reduced to decrease air ejection amounts and save energy, then the energy consumption is reduced, but the weft yarn may become slack causing defects in woven cloth
Solution Approach 1:
Multiple air-ejection-amount reducing patterns are predefined with different ejection period reduction parameters for each sub-nozzle-group set. These patterns offer varying degrees of period reduction (e.g., 0°, 5°, 10°, 15° crank angle reductions) allowing selection of appropriate parameter combinations that reduce air ejection while preventing weft yarn slacking
Solution Approach 2:
The system provides dynamically selectable ejection period configurations through the multiple reducing patterns. Operators can choose different patterns based on actual weaving conditions, yarn types, and production requirements, making the system adaptable and flexible in maintaining stability while reducing energy consumption
3Use of energy by moving object
If the ejection end times are advanced uniformly across all sub-nozzle groups to reduce air ejection, then the air ejection amounts are reduced, but the reduction effectiveness is limited due to constraints at the weft arrival side
Solution Approach 1:
The sub-nozzle groups are segmented into three sets that can be reduced independently rather than uniformly. This allows the intermediate and upstream sets to achieve greater reduction amounts without being constrained by the limited reduction possible at the downstream set near the weft arrival side, thereby improving overall reduction effectiveness
Solution Approach 2:
Different reduction amounts are applied locally to different sub-nozzle-group sets based on their positions and functions. The intermediate and upstream sets can have larger ejection period reductions applied to them compared to the downstream set, optimizing the overall air ejection reduction while maintaining weft insertion stability
Data Source
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AI summary
An ejection-period setting method for sub-nozzles (21) in an air jet loom is provided. The sub-nozzles (21) are divided into groups (1G to 13G) of sub-nozzles (21) that are connected to a common electromagnetic on-off valve (36). The groups (1G to 13G) are divided into downstream and upstream group sets (GU1 and GU3) which each include two or more groups and an intermediate group set (GU2) including the remaining groups. Ejection-amount reducing patterns (patterns hereinafter) are determined and stored in advance in an arbitrarily selectable state, each pattern being determined by setting an ejection-period reducing mode for each of subject group sets in units of predetermined periods so that each pattern includes the ejection-period reducing modes for all of the subject group sets, the subject group sets including the intermediate and upstream group sets (GU2 and GU3). In a process of setting the ejection periods of the sub-nozzles (21), ejection end times of the ejection periods are corrected when a pattern is selected by an operator.