Agricultural Cutter Bar Gap Closure via Stationary Knife Bridge
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Solution Overview
Problem
Existing cutting devices for agricultural machines often result in uncut strips when cutting crops close to the ground, leading to crop loss due to phase shifts in the drive frequency causing uneven movement of cutter bar sections, which fail to effectively close the gap between them.
Innovation Solution
A finger cutter bar design with mowing fingers forming counterblades and knife blades guided within the finger bar, utilizing a stationary knife blade bridge to ensure continuous cutting, and a phase offset of 80° to 100° to synchronize the movement of cutter bar sections, reducing the gap and minimizing uncut strips, along with a triple mowing finger arrangement for enhanced support and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cutter bar is divided into two parts with phase shift drive to reduce vibrations, then vibration and shaking losses are prevented, but uncut strips are created in the central contact area
Solution Approach 1:
A stationary knife blade bridge is introduced as an intermediary element between the two moving cutter bar sections. This stationary blade bridge spans the gap that forms during opposite movement of the cutter bar sections and ensures continuous cutting action, preventing uncut strips while allowing the cutter bar sections to move in opposite directions for vibration reduction.
Solution Approach 2:
The cutter bar is segmented into multiple sections (at least two cutter bar sections) that can move independently in opposite directions. This segmentation allows each section to be driven with a phase shift to reduce vibrations, while the stationary knife blade bridge connects these segments to maintain continuous cutting coverage.
2Reliability
If the cutter bar sections move in opposite directions to compensate oscillations, then vibrations are reduced, but the gap between sections increases creating uncut areas
Solution Approach 1:
The stationary knife blade bridge acts as a mediator that maintains cutting continuity across the gap formed by opposite movement of cutter bar sections. It ensures that even when sections move apart to compensate oscillations, the cutting action remains continuous without creating uncut areas.
Solution Approach 2:
The stationary knife blade bridge is pre-positioned to span the expected gap between cutter bar sections during their opposite movement. This preliminary positioning ensures that the bridge is already in place to maintain cutting continuity before the sections move apart, preventing any loss of cutting coverage.
3Loss of substance
If a finger cutter bar with mowing fingers is used to lift and cut crops, then crop losses are reduced, but the complexity of the device increases
Solution Approach 1:
The mowing fingers serve multiple functions: they lift crops stored on the ground before cutting, guides the knife blades during cutting, and work in coordination with the stationary knife blade bridge to ensure complete cutting coverage. This multi-functionality reduces crop losses without requiring separate lifting mechanisms.
Solution Approach 2:
The lifting and cutting functions are merged into a single integrated system where mowing fingers and knife blades work together. The mowing fingers lift the crops while the knife blades (both moving and stationary) simultaneously cut them, eliminating the need for separate lifting and cutting mechanisms.
Data Source
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AI summary
The present invention relates to a cutting device (2) for agricultural machinery with several cutter bar sections (4) extending over the working width of the cutting device (2), which are driven at least temporarily in opposite directions and whose blades (6) interact with counter blades fixed to the cutting device (2) in a shearing-like manner during a lifting movement of the cutter bar sections (4). In order to keep the width of the unmowed strip as small as possible or to avoid it entirely, it is proposed that a mowing finger (10) be arranged in the area of a gap (22) that results from the movement of the cutter bar sections (4) in the area of the opposing ends (8) of adjacent cutter bar sections (4) and which continuously decreases and increases in accordance with the movement of the cutter bar sections (4).In addition to the transverse cutting edges (16) of a stationary knife blade (14) in the area of this mower finger (10), which run beveled towards the direction of travel (V) of the cutting device (2), the cutting edges (16) of this knife blade (14) have a V-shaped arrangement that widens in the opposite direction of travel (V), and cutting edges (20) are formed on the outer end faces of the outer knife blades (18) which are attached to the mutually facing ends (8) of adjacent cutter bar sections (4), which run parallel to the direction of travel of the cutting device (2), wherein a drive (26) of the adjacent cutter bar sections (4) has a phase offset of between 80° and 100°.