String Mower Head Shielding Element Dirt Ejection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing line mowing heads for brush cutters tend to become soiled during operation, leading to dirt accumulation and increased wear due to clippings and debris getting caught in the cutting lines.
Innovation Solution
A line mowing head design featuring a shielding element that directs dirt away from the cutting line path, combined with a widening peripheral wall and helical roof surface to enhance dirt ejection and reduce soiling, along with a clamping device for secure line fixation and easy replacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the inner area of the base body is open toward the underside to allow cutting line insertion and removal, then ease of operation is improved, but the line mowing head becomes soiled with clippings and dirt accumulation
Solution Approach 1:
A shielding element is introduced as an intermediary component between the cutting lines and the incoming dirt/clippings. This shielding element creates a clean zone by blocking the direct path of contaminants to the cutting lines, allowing the inner area to remain open for easy line replacement while preventing soiling.
Solution Approach 2:
The inner area is segmented into a clean zone and a dirty zone by the shielding element. The clean zone contains the cutting lines protected from contaminants, while the dirty zone allows clippings to accumulate and be ejected outward, maintaining both accessibility and cleanliness.
2Object-affected harmful factors
If the peripheral wall widens toward the underside to eject dirt outward, then dirt ejection is improved, but the structural complexity increases
Solution Approach 1:
The peripheral wall features a curved or conical widening toward the underside, creating a natural ejection path for dirt and clippings. This curved geometry utilizes centrifugal force during rotation to propel contaminants outward and downward, achieving effective dirt ejection through simple geometric form rather than complex mechanical structures.
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
Significantly reduces the tendency of the line mowing head to become soiled, preventing dirt accumulation and associated wear, while maintaining easy line replacement and accessibility.
Implementation Method 1
the section of the cutting line running in the inner area being arranged in the lee of the shielding element with respect to the direction of rotation. It has been shown that a shielding element, in the slipstream of which the cutting line runs, can significantly reduce the tendency of the line mowing head to become soiled.
Implementation Method 2
the roof surface has at least one helical section which is arranged in front of the shielding element and on which the shielding element adjoins. The helical section is a section in which the distance between the roof surface and the plane of the underside increases in the direction of rotation.
Implementation Method 3
the peripheral wall delimiting the inner area radially outwards in relation to the axis of rotation widens in at least one section in the direction of the plane of the underside of the base body. This helps dirt that has accumulated in the interior to be guided out of the interior when centrifugal force acts on the peripheral wall and can be ejected downwards out of the line mowing head.
Data Source
AI summary
A trimmer head (5) for a brushcutter is driven to rotate about a pivot axis (7) in one direction (11) during operation. The trimmer head (5) has a base body (10) to which at least one cutting line (8, 9) is attached and which has an underside (13) facing the ground during operation. The cutting line (8, 9) extends from an outer surface (14) of the base body (10) through an opening (22, 23) into an inner area (15) of the base body (10) that is open towards the underside (13) of the base body (10). To minimize soiling of the trimmer head (5) during operation, a shielding element is provided in the inner area (15), and the section (16, 17) of the cutting line (8, 9) running in the inner area (15) is positioned in the lee of the shielding element with respect to the direction of rotation (11).