Air Jet Loom Valve Timing Display for Gentle Weft Braking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing air jet looms cause an impact on weft yarns when stopped by weft stop pins, which can lead to weaving errors or yarn contact with adjacent warp yarns, and existing solutions either delay the start timing or risk insertion errors.
Innovation Solution
An air jet loom with an information display device that adjusts the operation pattern of sub-valves to decrease the weft yarn's traveling speed before stopping, using detectors to determine optimal valve operation patterns that minimize impact without changing the weft insertion start timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the weft insertion start timing is delayed to allow longer braking time, then the impact on weft yarn is decreased, but the arrival time at the final insertion point is delayed causing weft insertion error
Solution Approach 1:
The patent divides the weft insertion process into multiple phases by controlling different valves (main valve and sub-valves) at different timing. The sub-valves are controlled to operate after the main valve, creating a segmented braking sequence that gradually reduces weft yarn speed. This segmentation allows the system to achieve both impact reduction and timing accuracy by applying braking forces in distinct stages rather than a single delayed action.
Solution Approach 2:
The patent applies preliminary braking action through the sub-valves before the weft yarn reaches the final insertion point. By controlling the sub-valves to operate in advance with specific timing, the system prepares the weft yarn for gentle stopping. The detectors monitor the weft yarn position and trigger the sub-valve timing accordingly, ensuring that the braking action is initiated at the optimal moment to reduce impact while maintaining insertion accuracy.
2Manufacturing precision
If the weft insertion start timing is advanced to maintain arrival timing, then weft insertion accuracy is maintained, but the weft yarn may contact adjacent warp yarn causing defects
Solution Approach 1:
The patent implements dynamic control of valve timing based on real-time detection of weft yarn position and speed. The control device adjusts the timing of sub-valve operation dynamically according to the actual insertion state. This dynamic adjustment allows the system to advance timing when needed to maintain accuracy while controlling the weft yarn speed to prevent contact with adjacent warp yarns, resolving the contradiction between timing accuracy and contact prevention.
Solution Approach 2:
The patent uses detectors to provide feedback on weft yarn position and insertion progress. This feedback information is fed back to the control device, which then adjusts the sub-valve timing accordingly. The closed-loop feedback system enables real-time optimization of the insertion timing, ensuring that the weft yarn is inserted accurately without contacting adjacent warp yarns by continuously monitoring and adjusting the process parameters.
3Extent of automation
If photoelectric sensors are placed away from the weft package to detect weft yarn before stopping, then the traveling speed can be calculated for control, but the system complexity increases with multiple sensors and calculation processes
Solution Approach 1:
The patent makes the detectors serve multiple functions: they detect both the position of the weft yarn and provide timing information for controlling the sub-valves. The same detection system used for monitoring insertion progress is also utilized for calculating traveling speed and triggering the braking sequence. This multi-functionality reduces the need for separate sensing systems and simplifies the overall control architecture while maintaining automatic speed control capability.
Solution Approach 2:
The patent combines the detection function and control function into an integrated system. The detectors are positioned to simultaneously provide data for both monitoring the weft yarn position and triggering the sub-valve operation. The control device merges the timing information from detectors with the valve control signals, creating a unified control mechanism that reduces system complexity while achieving automatic speed and timing control.
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 effectively reduces the impact on weft yarns by optimizing valve operation patterns, ensuring timely insertion and maintaining productivity without additional costs or production delays.
Implementation Method 1
a weft yarn is inserted and travels through a weft passage in a reed by compressed air discharged from a main nozzle and a sub-nozzle
Implementation Method 2
The jet loom disclosed in JP H07 026443 A includes a plurality of photoelectric sensors for detecting the weft yarn
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
An information display device (100) of an air jet loom includes: a pattern storage unit (111); a pattern extractor (121); and a display (202). The air jet loom includes a weft insertion apparatus (10); a first weft detector (40) for outputting a final insertion point arrival time (Tw); and a second weft detector (41) for outputting an intermediate insertion point arrival time (Ti). The pattern storage unit (111) stores operation patterns (P1-P3) of sub-valves (32) in which operations of the respective sub-valves (32) are set, acquires the final insertion point arrival time (Tw) and the intermediate insertion point arrival time (Ti) in each operation pattern (P1-P3), and stores a time difference (ΔT) between the final insertion point arrival time (Tw) and the intermediate insertion point arrival time (Ti) in each operation pattern (P1-P3). The pattern extractor (121) is configured to extract an operation pattern (P1) that maximizes the time difference (ΔT) from the operation patterns (P1-P3). The display (202) is configured to display the extracted operation pattern (P1).