Baler Knotter Mis-Tie Detection Using Twine Tension Sensing
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Solution Overview
Problem
Existing agricultural balers often experience mis-ties due to improper twine tension, leading to improperly tied bales that require rework, which can be avoided with an improved detection system.
Innovation Solution
A knotter assembly with a mis-tie detection device that monitors twine tension using a position indicator and sensing mechanism to detect improper twine holding, sending a signal to the electronic control unit when a mis-tie is likely to occur.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mis-tie detection device is added to the knotter assembly, then the reliability of bale tying is improved, but the device complexity increases
Solution Approach 1:
The mis-tie detection device monitors twine tension and position before the knotting process completes, detecting potential mis-ties in advance. The position indicator and sensing mechanism are positioned to detect twine holding status prior to knot formation, allowing preventive action before defective bales are produced.
Solution Approach 2:
A position indicator serves as an intermediary element between the twine and the sensing mechanism. The indicator is movably positioned and interacts with the twine directly, translating twine position and tension into mechanical movement that the sensing mechanism can detect, thereby mediating the detection process.
2Productivity
If continuous monitoring of twine tension is implemented, then the productivity is improved by reducing rework, but the use of energy increases
Solution Approach 1:
The detection system operates periodically during the knotting cycle rather than continuously. The position indicator is activated and monitored at specific intervals corresponding to the knotting operations, detecting twine position and tension only when needed in the periodic baling cycle, thereby reducing energy consumption while maintaining productivity benefits.
3Measurement precision
If a position indicator with movable sensing mechanism is used, then the measurement precision of twine position is improved, but the device complexity increases
Solution Approach 1:
The position indicator is designed to be self-actuating through the tension and position of the twine itself. The twine's own physical state (tension and position) directly moves the indicator without requiring external actuators or complex sensing systems, achieving precise measurement while minimizing added complexity.
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 system effectively detects mis-ties, allowing for timely corrective action to prevent subsequent bales from being improperly tied, reducing rework and improving bale tying efficiency.
Implementation Method 1
Tension in the twine during a knotting cycle causes the position indicator to move from a first condition to a second condition
Data Source
AI summary
A knotter assembly includes a twine holder and a twine disc assembly having parallel discs for holding twine during a knotting cycle. The knotter assembly further includes a mis-tie detection device configured to monitor the twine being held with the twine holder in a notch of the twine disc. The mis-tie detection device has a movable position indicator positioned adjacent the twine disc. The position indicator has a twine-receiving groove that aligns with the notch in the twine disc such that the twine is simultaneously held in the notch and groove. Tension in the twine during a knotting cycle causes the position indicator to move from a first condition to a second condition. The mis-tie detection device also has a sensing mechanism configured to determine the position of the position indicator.