Front Mower Trapezoidal Four-Bar Kinematics
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Solution Overview
Problem
Mowers for front mounting on agricultural towing vehicles face challenges in ground adjustment dynamics, particularly with heavy mowers, where ground adjustment is limited and requires high bearing weight, leading to suboptimal mowing results and increased wear and tear.
Innovation Solution
The mower employs trapezoidal four-bar kinematics with an instantaneous center located behind the mower and above the ground surface, combined with an excavation cylinder and relief cylinder, allowing for dynamic ground adaptation with low bearing weight, and a parking flap for secure parking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the mower uses front linkage coupling for ground adjustment, then the mower can be coupled to the towing vehicle, but the ground adjustment dynamics are limited and require high bearing weight
Solution Approach 1:
The patent changes the geometric parameters of the four-bar linkage system, specifically positioning the instantaneous center above the ground surface and behind the mower. This parameter change transforms the ground adjustment mechanism, enabling high dynamics with low bearing weight by altering the fundamental kinematic configuration rather than simply adjusting weights or forces.
2Quantity of substance
If heavy mowers are used, then the mowing capacity increases, but the ground adjustment dynamics deteriorate and bearing weight increases
Solution Approach 1:
Instead of allowing heavy mowers to directly burden the ground through traditional linkage, the patent inverts the approach by positioning the instantaneous center above ground level. This inversion creates a leveraged mechanical advantage where the heavy mower weight is effectively utilized to achieve both high mowing capacity and superior ground adjustment dynamics simultaneously.
3Device complexity
If traditional four-bar kinematics is used, then the structure is simple, but the instantaneous center is below ground level reducing ground adaptation
Solution Approach 1:
The patent moves the instantaneous center from the traditional below-ground position to an above-ground position, effectively utilizing the vertical dimension in a new way. This dimensional repositioning of the instantaneous center transforms the ground adaptation capability while maintaining the simplicity of the four-bar linkage structure, achieving better performance without increased complexity.
Data Source
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AI summary
Mower (10) for front mounting on an agricultural tractor, comprising a mounting frame (11) via which the mower can be coupled to a front linkage of an agricultural tractor, and a support frame (12) on which a mowing unit (13) is attached, wherein the support frame (12) and the mounting frame (11) are coupled to each other on the one hand via a pivot frame (18) and on the other hand via a link (19) forming a trapezoidal four-bar linkage such that the pivot frame (18) engages the support frame via a first pivot axis (20) and the mounting frame via a second pivot axis (21), and that the link (19) engages the support frame via a third pivot axis (22) and the mounting frame via a fourth pivot axis (23), wherein the trapezoidal four-bar linkage is configured as follows:that a first straight line (24) extending through the first pivot axis and the second pivot axis and a second straight line (25) extending through the third pivot axis and the fourth pivot axis intersect at an instantaneous center of rotation (26), which, when the mower is coupled to a front attachment of an agricultural tractor, lies behind the mower and above a ground surface to be mowed in all positions of the four-bar linkage kinematics.