Wing Float Linkage for Combine Draper Header
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Solution Overview
Problem
Existing combine harvester headers struggle to maintain a consistent float force on lateral wings while navigating uneven terrain, leading to variable cutting performance and crop feeding efficiency.
Innovation Solution
The implementation of a resilient float element system with a float linkage that adjusts mechanical advantage to maintain a constant float force on the wings, independent of their position relative to the center section, using a combination of hydraulic cylinders and accumulators, and a four-bar linkage mechanism to accommodate ground undulations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a passive hydraulic cylinder is used as a damper to mediate rotation of the wings, then the float force exerted on the wings varies with wing position, but the system structure remains simple
Solution Approach 1:
The float linkage acts as an intermediary mechanism between the resilient float element and the wing. It includes a float arm pivotally connected to the wing and a connection link connecting the float arm to the center section. This intermediary linkage transforms the direct force application into a mechanical advantage system that compensates for position-dependent force variations.
Solution Approach 2:
The float linkage changes the mechanical advantage parameter as the wing moves through different positions. When the wing is in different orientations, the linkage geometry changes, thereby adjusting the force transmission ratio to compensate for the varying output force of the resilient float element, maintaining consistent overall float force on the wing.
2Reliability
If the wing position changes relative to the center section, then the mechanical advantage of the float linkage varies, but the float force output should remain constant
Solution Approach 1:
The float linkage is designed as a dynamic mechanism where the mechanical advantage automatically adjusts with wing position. The linkage geometry changes dynamically as the wing moves, creating a variable mechanical advantage that compensates for the changing force output of the resilient float element, ensuring reliable and consistent float force application regardless of wing position.
Solution Approach 2:
The float linkage employs an asymmetric four-bar mechanism where the link lengths and pivot positions are specifically designed to create the desired mechanical advantage variation. This asymmetric configuration ensures that the force multiplication effect increases or decreases appropriately to counterbalance the resilient float element's force output changes.
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 ensures consistent low cutting of crops across uneven terrain and maintains efficient crop feeding into the combine harvester, without the need for active sensing or control systems, by automatically adjusting the float force to compensate for changes in ground conditions.
Implementation Method 1
Each resilient float element is operable to produce a force output that varies with a position of the wing with respect to the center section
Implementation Method 2
Each resilient float element is coupled between the center section and the respective one of the first and second wings by a respective float linkage operable through a range of positions to vary a mechanical advantage between the resilient float element and the respective wing
Data Source
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AI summary
A combine draper header and method of floating a wing of the same from a center section of the draper header. The wing is movably supported with respect to the center section to enable movement of the wing between a first position and a second position. The wing is supported with respect to the center section with a resilient float element. Increasing amounts of energy are stored in the resilient float element through movement of the wing from the first position to the second position. The resilient float element is re-oriented with a float linkage to reduce the mechanical advantage of the resilient float element for supporting the wing through movement of the wing from the first position to the second position, thus buffering the wing from a force increase from the resilient float element.