Weft Thread Insertion Timing Control
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Solution Overview
Problem
Airjet weaving machines consume excessive compressed air when inserting weft threads, particularly when dealing with threads of different lengths and speeds, leading to inefficient air usage and potential thread misalignment.
Innovation Solution
A method that adjusts the timing of compressed air supply to relay blowers based on the estimated trajectory of the weft thread, using a reference value calculated from the time difference between the weft thread's arrival and unwinding instants, allowing for delayed air supply to reduce air consumption and accommodate varying thread lengths and speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If compressed air is supplied to relay blowers for a fixed period to support both fast and slow weft threads, then all threads are adequately supported, but compressed air consumption increases
Solution Approach 1:
The patent applies dynamics by making the compressed air supply timing adaptive rather than fixed. The start time of compressed air supply to each relay blower is dynamically adjusted based on the actual weft thread speed and position detected by sensors. This allows the system to provide adequate support for both fast and slow threads while avoiding unnecessary air consumption when threads arrive earlier or later than average.
Solution Approach 2:
The patent implements feedback mechanisms using arrival detectors and winding detectors that continuously monitor weft thread position and speed. This feedback information is used to adjust the compressed air supply timing in real-time, ensuring optimal support for each thread while minimizing energy waste. The system learns from actual thread behavior to optimize air supply patterns.
2Loss of energy
If compressed air supply timing is optimized for fast weft threads, then air consumption is reduced, but slow weft threads may not be adequately supported
Solution Approach 1:
The patent applies local quality by providing differentiated compressed air support tailored to each weft thread's specific needs. Instead of using a uniform timing strategy for all threads, the system adjusts air supply parameters locally based on detected thread characteristics. Fast threads receive later air supply while slow threads receive earlier air supply, ensuring each thread gets appropriate support without compromising overall reliability.
3Loss of energy
If the start time of compressed air supply is delayed to reduce air consumption, then energy efficiency improves, but thread trajectory control may be compromised
Solution Approach 1:
The patent uses dynamics to adapt the compressed air supply timing to actual thread behavior. Rather than using a fixed delayed timing that might compromise trajectory control, the system dynamically adjusts air supply start times based on real-time detection of thread position and speed. This ensures trajectory precision is maintained while achieving energy savings through optimized rather than simply delayed air supply.
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 compressed air consumption by optimizing the start and end times of air supply to relay blowers, ensuring efficient support for both fast and slow weft threads, thereby minimizing air usage and thread waste.
Implementation Method 1
transported through a shed by means of compressed air blown by at least one main blower and by successive relay blowers
Data Source
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AI summary
A method for inserting a weft thread (4, 5), comprising the steps of activating the relay blowers (12, 13, 14, 15, 16, 17, 18, 19, 20) successively, with the advancement of the weft thread (4, 5) through the shed (1), detecting an average arrival instant (TA, TA1) at which a leading end of an average weft thread (4, 5) reaches an arrival detector (25) arranged at an arrival end of the shed (1), detecting an instant (TLW) at which the last winding is unwound from the winding drum (53), determining as a reference value (DT) the time difference between an average arrival instant (TA, TA1) and an average instant (TLW) at which the last winding is unwound from the winding drum (53), determining at least one point (Pi) of an estimated trajectory (49, 49A, 49B, 49C) of the leading end of the average weft thread (4, 5) transported through the shed (1) as a function of the reference value (DT), and adapting the start of the period of time (40, 41, 42, 43, 44, 45, 46, 47, 48) for supply of compressed air to at least one of the relay blowers (12, 13, 14, 15, 16, 17, 18, 19, 20) to this estimated trajectory (49, 49A, 49B, 49C). An airjet weaving machine with a device for applying this method.