Weighing System for Yarn Bobbin Density Control
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Solution Overview
Problem
Existing yarn rewinding devices face issues with maintaining constant yarn density during the winding cycle, leading to uneven bobbin density, which is critical for applications like sewing yarns where uniformity is essential.
Innovation Solution
A device with a controller and a weighing system that adjusts the thread brake based on the weight of the feed bobbin, ensuring consistent yarn tension and density, utilizing a load cell for precise weight measurement and a damping element to minimize vibrations, along with a height-adjustable feed table for optimal yarn alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the feed bobbin diameter decreases during unwinding, then the yarn comes off more easily, but the yarn tension is reduced and bobbin density becomes uneven
Solution Approach 1:
The thread brake is made dynamically adjustable through a servomotor that continuously modifies the brake force based on real-time feed bobbin weight measurements. This dynamic adjustment compensates for the changing unwinding conditions as the bobbin diameter decreases, maintaining constant yarn tension and ensuring uniform bobbin density throughout the winding process
Solution Approach 2:
A feedback control system is implemented where the weigh cell continuously measures the feed bobbin weight, the controller processes this information to determine the current unwinding state, and the servomotor adjusts the thread brake force accordingly. This closed-loop feedback ensures that yarn tension remains constant despite changing bobbin diameter
2Manufacturing precision
If a weighing device is added to measure feed bobbin weight, then bobbin density uniformity can be maintained, but device complexity increases
Solution Approach 1:
The thread brake serves multiple functions: it traditionally provides yarn tensioning, and now additionally serves as the actuation point for the feedback-controlled density uniformity system. By adjusting the brake force dynamically, the same component achieves both its original function and the new density control function, reducing the need for separate dedicated components
Solution Approach 2:
The servomotor acts as an intermediary between the weight measurement system and the thread brake mechanism. Rather than directly modifying the brake mechanism itself, the servomotor provides precise rotational control to adjust brake force, simplifying the integration of the weighing system with the existing tensioning mechanism
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 ensures a consistent yarn density throughout the winding cycle, preventing interruptions due to empty bobbins and producing uniformly wound bobbins, enhancing the quality of yarns for specific applications.
Implementation Method 1
A holder of the bobbin mandrel comprises a weighing of the feed bobbin
Implementation Method 2
US 20190330774 A1 discloses a device for weighing feed bobbins. In this case, the weighing device is provided with a damping device to prevent vibrations being transferred to the weighing device or to the weigh cells
Implementation Method 3
having a thread brake for setting a yarn tension
Data Source
AI summary
A device for rewinding yarns from a feed bobbin onto a bobbin tube includes a controller, a machine frame, and a bobbin mandrel held in a rotationally fixed manner in the machine frame to receive the feed bobbin. A winding device includes a thread brake to set a yarn tension in the yarn rewound from the feed bobbin onto the bobbin tube. A holder for the bobbin mandrel includes a weighing system in communication with the controller, wherein an adjustment of the thread brake is provided by the controller based on a weighing of the feed bobbin.