Yarn Tension Sensor Zero Point Calibration via Brake Relief Cycles
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Solution Overview
Problem
Thread tension sensors in textile machines face challenges in accurately determining the zero point, especially when the thread is stationary, due to potential jamming and the need for additional lifting units, which complicates the regulation of thread tension.
Innovation Solution
A method involving a braking device with a cone-shaped brake body and magnetic elements to control thread tension, where brake relief cycles are used to determine the zero point by changing the brake signal from an initial value to a minimum value and back, allowing for reliable determination of the zero point without jamming, even when the thread is stationary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the thread is stationary for zero point determination, then the sensor can be calibrated, but the sensor may be jammed by the thread and brake body
Solution Approach 1:
The patent applies preliminary action by performing brake relief cycles before zero point determination. The control unit reduces the brake signal to minimize brake body contact with the thread, preventing jamming before it occurs during the stationary measurement phase. This preparatory reduction of braking force ensures the thread remains free while maintaining measurement accuracy.
Solution Approach 2:
The patent applies dynamics by dynamically adjusting the brake signal during zero point determination. The control unit continuously modifies the brake signal strength based on the determination phase, reducing it to prevent jamming while the thread is stationary. This dynamic control allows the system to adapt the braking force to the specific requirements of zero point calibration.
2Measurement precision
If additional lifting units are used to prevent jamming, then the sensor can determine zero point accurately, but the device complexity increases
Solution Approach 1:
The patent applies self-service by using the existing brake device to serve the dual purpose of tension control and jamming prevention. The control unit intelligently reduces the brake signal during zero point determination, allowing the brake mechanism itself to prevent thread jamming without requiring separate lifting units. This eliminates additional hardware while maintaining measurement accuracy.
Solution Approach 2:
The patent applies universality by making the brake signal control unit perform multiple functions: it controls thread tension during normal operation and simultaneously prevents jamming during zero point determination by reducing the brake signal. This multi-functionality eliminates the need for dedicated lifting units, simplifying the overall system structure.
3Reliability
If the brake signal is reduced to determine zero point, then jamming is prevented, but thread tension control may be affected
Solution Approach 1:
The patent applies periodic action by implementing periodic brake relief cycles during zero point determination. The control unit rhythmically reduces and restores the brake signal in controlled cycles, ensuring the thread remains free from jamming while maintaining overall tension control. This periodic modulation allows temporary reduction of braking force without compromising the system's ability to control thread tension during normal operation.
Solution Approach 2:
The patent applies dynamics by dynamically adjusting the brake signal strength based on operational phase. During zero point determination, the control unit reduces the brake signal to prevent jamming, while during normal operation, it restores full braking force for proper tension control. This dynamic adaptation allows the system to optimize both reliability during calibration and tension control during production.
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 method ensures accurate and reliable determination of the zero point for thread tension sensors, preventing jamming and allowing for precise regulation of thread tension, even when the thread is stationary, thereby improving the control of thread delivery in textile machines.
Implementation Method 1
The thread tension is adjusted by a braking device with at least one braking body in the course of the thread after the storage body
Implementation Method 2
The actuating elements are designed as magnetic elements, with one magnetic element being movable in the magnetic field of the other magnetic element and acting on the brake body or bodies
Data Source
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AI summary
In a method for controlling the yarn supply from at least one yarn supply device (1) to a textile machine, a yarn (40) is drawn from a storage body (3) of the yarn supply device (1) by the textile machine. The yarn tension of the yarn (40) is adjusted by a braking device with at least one brake element (8) in the yarn path after the storage body (3) and by an adjusting device. At least one actuating element of the adjusting device acts on the brake element(s) (8), and the actuating element(s) are controlled by a braking signal. A yarn tension unit adjusts the braking signal to a reference value (Mref) for regulating the yarn tension, whereby measured values (Mi) of the yarn tension are determined by a tension measuring unit, and the difference (Mdiff) between a measured value (Mi) and the reference value (Mref) is minimized.To determine the zero point (M0) of the tension measuring unit, a brake release (BE) with at least one release cycle is performed by a determining unit (70) of the thread tension unit while the thread (40) is stationary. During each release cycle, the brake signal changes from an initial value (Ia) to a value (Imin) at which the brake element(s) (8) are completely released, and then back to the initial value (Ia). An offset value (M0) of a measuring device of the tension measuring unit, measured at the value (Imin) of the brake signal during the last release cycle, is used to determine the zero point.