Thread Deflection Unit with Strain Gauge Tension Feedback
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Solution Overview
Problem
Existing thread deflection units for winding machines face challenges in efficiently detecting and compensating for dynamic tension changes and stress peaks during the winding process, leading to potential thread damage and machine stoppages, while also requiring significant installation space and being unable to accurately measure thread length changes.
Innovation Solution
A compact thread deflection unit is designed with a predetermined bending area and a spring element mechanically connected in series, allowing for independent dimensioning of flexibility and 'memory' function to compensate for tension changes, using strain gauges to provide tension feedback for spindle drive regulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a dancer arm with eccentric disk is used to detect thread tension, then tension detection is achieved, but the installation space required is large and the structure is complex
Solution Approach 1:
The patent extracts the essential function of tension detection from the complex dancer arm mechanism and implements it using a simple roller mounted on a bending beam with strain gauges. The roller can deflect in the direction of the thread force, and the strain gauges directly measure the bending moment, eliminating the need for eccentric disks, springs, and complex mechanical linkages while maintaining accurate tension detection capability
Solution Approach 2:
The patent replaces the mechanical dancer arm system with an electromechanical system using strain gauges that convert mechanical bending into electrical signals. This substitution allows for more precise measurement and simplifies the mechanical structure by eliminating moving mechanical components like eccentric disks and spring-loaded arms
2Volume of stationary object
If a rigid cantilever arm with strain gauge is used, then installation space is reduced, but the ability to compensate for dynamic tension changes is lost
Solution Approach 1:
The patent makes the roller mounting dynamic by allowing the roller to deflect freely in the direction of the thread force through the bending beam. This dynamic capability enables the system to automatically compensate for tension variations and stress peaks during winding operations, while the overall footprint remains compact compared to dancer arm mechanisms
3Measurement precision
If the roller is constrained in the plane of thread deflection, then measurement accuracy is improved, but the memory function for tension compensation is reduced
Solution Approach 1:
The patent resolves the contradiction by allowing the roller to deflect in the direction of the thread force (one dimension) while keeping the strain gauge measurement axis perpendicular to this deflection direction (another dimension). The strain gauge measures bending in its specific orientation, which correlates with thread tension, while the roller's freedom to deflect in the force direction provides the necessary compliance and memory function for tension compensation
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 solution effectively reduces tension peaks, minimizes installation space, and provides accurate tension measurement, enabling better thread guidance and preventing thread damage, while allowing for adjustable stiffness to accommodate different materials and operating conditions.
Implementation Method 1
a predetermined bending area 17 with a strain gauge 18 arranged in this
Implementation Method 2
a spring element 19, which is arranged mechanically in series with the predetermined bending area 17 with the strain gauge 18
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The thread diverging unit (4) has spring element (19) over which bobbin (13) is arranged in such a manner that tension in the spooling goods is changed. An ideal flexible region (17) with resistance strain gauge (18) and spring element is arranged in mechanical series connection. The ideal flexible region is formed separately with the spring element.