Pneumatic Spinning Device Timing Control for Yarn Joining
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Solution Overview
Problem
Conventional spinning machines face issues with adjusting the length of the fiber bundle portion at the yarn end, leading to defects such as incomplete twisting and unreliable yarn joining due to improper timing of air injection and movement of the pneumatic spinning device.
Innovation Solution
The spinning machine incorporates a draft device and a pneumatic spinning device that can be moved between a spinning and a receded position, with adjustable timings for air injection stoppage and device movement, allowing for precise control over the fiber bundle length by adjusting the first and second timings relative to the drafting operation stoppage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the air injection is stopped early when drafting operation is stopped, then the fiber bundle portion length is shortened, but the yarn end cannot be reliably caught during yarn joining operation
Solution Approach 1:
The pneumatic spinning device is moved to the receded position in advance before the air injection is completely stopped. This preliminary movement creates space and timing buffer that allows the fiber bundle portion to be properly formed and separated, ensuring both appropriate length and reliable yarn joining capability.
Solution Approach 2:
The system dynamically coordinates the timing between air injection stoppage and pneumatic spinning device movement. By making the air injection timing adjustable relative to the drafting operation stoppage, the system can optimize the fiber bundle portion length while maintaining yarn joining reliability through proper sequencing of operations.
2Length of moving object
If the pneumatic spinning device moves too early from spinning position, then the fiber bundle portion length is shortened, but incomplete twisting occurs at the yarn end
Solution Approach 1:
The air injection is maintained for a period after the pneumatic spinning device reaches the receded position. This preliminary continuation of air injection ensures that twisting is completed at the yarn end before the device fully transitions, achieving both proper fiber bundle length and complete twisting.
Solution Approach 2:
The system dynamically adjusts the coordination between device movement and air injection timing. By making the air injection stoppage timing adjustable relative to the drafting operation stoppage, the system optimizes the sequence to ensure twisting completeness while achieving the desired fiber bundle portion length.
3Reliability
If the air injection is stopped late when drafting operation is stopped, then the twisting is maintained, but the fiber bundle portion becomes excessively long and remains on the yarn accumulating roller
Solution Approach 1:
The pneumatic spinning device is moved to the receded position in advance before air injection is completely stopped. This preliminary movement allows the system to control the fiber bundle portion length by creating a timing buffer, preventing excessive length while maintaining twisting quality through continued air injection during the transition.
4Productivity
If the drafting operation is stopped without coordinating air injection timing, then production efficiency is maintained, but inconsistent fiber bundle portion length occurs
Solution Approach 1:
The system uses feedback control to coordinate the air injection stoppage timing with the drafting operation stoppage. By monitoring the drafting operation status and adjusting the air injection timing accordingly, the system maintains spinning efficiency while ensuring consistent fiber bundle portion length through proper synchronization of operations.
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 configuration enables accurate adjustment of the fiber bundle length, ensuring reliable twisting and yarn joining operations by ensuring twists are applied consistently, preventing fiber bundle remnants and improving yarn end catching during joining.
Implementation Method 1
produce a yarn by applying twists to the drafted fiber bundle by injecting air to a spinning chamber
Implementation Method 2
blowing pressurized air to a sliver during piecing
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A spinning unit 2 includes a draft device 6 adapted to draft a fiber bundle F and a pneumatic spinning device 7 arranged movable to a spinning position and a receded position and adapted to produce a yarn Y by applying twists to the drafted fiber bundle F by injecting whirling flow of air to a spinning chamber while being located at the spinning position. In the spinning unit 2, at least one of a first timing, which is a timing at which injection of the air is stopped when a drafting operation of the draft device 6 is stopped, and a second timing, which is a timing at which the pneumatic spinning device 7 starts being moved from the spinning position to the receded position when the drafting operation of the draft device 6 is stopped, is adjusted.