Agricultural Header Height Sensor With Reversing Joint
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Solution Overview
Problem
Existing header height sensors for agricultural combines are prone to damage due to rough handling and collect debris, leading to inaccurate readings, especially when flexible coil springs and balls are used, which lose shape and functionality.
Innovation Solution
A header height sensor with a rigid sensor arm and a reversing joint supported by dual springs, featuring a mechanical stop and a rotary position sensor, allows for lateral movement and rotation without flattening, ensuring accurate height measurement and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a flexible sensor arm with coil spring is used to allow lateral movement, then the sensor can handle rough treatment and directional changes, but the spring collects plant matter and loses its original shape, leading to inaccurate readings
Solution Approach 1:
The sensor arm is divided into multiple rigid segments connected by joints, allowing lateral movement through joint articulation rather than spring flexing. This segmentation maintains measurement accuracy while providing the needed adaptability to rough treatment and directional changes.
Solution Approach 2:
The flexible coil spring mechanical system is replaced with a rigid arm supported by a reversibly joint mechanism. The reversibly joint uses a pair of springs in a controlled configuration with mechanical stops to permit limited lateral movement only when necessary, preventing the spring from collecting plant matter and maintaining measurement precision.
2Ease of operation
If a ball contact point is used for ground engagement, then the sensor can roll over terrain, but the spherical shape gathers dirt and plant matter, reducing measurement accuracy
Solution Approach 1:
The spherical ball contact point is replaced with a flat or curved surface that maintains ground contact capability without the hollow center of a sphere. This prevents plant matter from entering and accumulating at the contact point, ensuring continuous accurate measurements while still allowing the sensor to follow terrain variations.
3Strength
If the sensor arm is made large and strong to avoid damage, then durability improves, but the sensor becomes more complex and harder to install
Solution Approach 1:
The reversibly joint is positioned to allow the rigid sensor arm to deflect laterally before damage can occur. This pre-planned flexibility path protects the rigid arm from bending forces, maintaining durability without requiring the arm itself to be made larger or more complex.
Solution Approach 2:
The sensor system combines rigid materials for the measurement arm with elastic materials for the reversible joint springs. This composite approach provides both the strength needed for durability and the flexibility needed for protection, avoiding the need for an oversized single-material construction.
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 provides a robust, accurate, and durable header height sensor that maintains precise measurements even under harsh conditions, reducing damage and debris-related issues, enabling effective header height control during crop harvesting.
Implementation Method 1
a pair of springs disposed on either side of the upper end, the pair of springs being coupled to the housing and to the upper end to push the upper end against the mechanical stop
Implementation Method 2
a rotary position sensor coupled to bracket and coupled to reversing joint such that movement of the reversing joint with respect to the rotary position sensor causes an electrical signal from rotary position sensor to change as a function of the relative rotation
Data Source
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AI summary
A header height sensor (102) for an agricultural harvester has an elongate sensor arm (112), a reversing joint (114) and a rotary sensor (116) mounted to a bracket (106) that is fixed to a plastic point (100) of a harvesting head.