A basic study of branch cutting mechanisms for happy trees
Date Issued
2008
Date
2008
Author(s)
Huang, Sheng-Feng
Abstract
The highest level of camptothecin is found in the leaves of camptotheca (happy tree). This is a potent anti-cancer material, and in trying to harvest the leaves, farmers have so far lacked a suitable machine to pluck happy tree’s baby leaves effectively. The purpose of this study was to find the best device for plucking leaves from happy trees, and then use software to design a prototype of the leaf-plucking machine.n this study, the reciprocating knife mechanism was chosen. Two types of reciprocating cutting devices were used. One is a reciprocating cutterbar from a rice combine. It has a horizontal pattern and a serrated blade. The other is a cutterbar from a tea plucking machine that has an arc pattern and a smooth blade.n order for the cutting simulation to be realistic, this experiment tested the whole cutting mechanism at two different forward speeds (0.52 m/s and 0.63 m/s) and various knife velocities (0.38 m/s and 0.55 m/s for the reciprocating cutterbar from a rice combine, 0.88 m/s and 0.99 m/s for the cutterbar from a tea plucking machine) and recorded the torque and ratio of broken branches to determine which one is the best cutting mechanism.he result showed the ratio of broken branches for the reciprocating cutterbar from a rice combine at two different forward speeds and knife velocities is less than 5%. At 0.52 m/s forward speed for the reciprocating cutterbar, the ratio of broken branches for the tea plucking machine was less than 5%.wo additional knife velocities (0.33 m/s and 0.70 m/s) and one additional forward speed (0.84 m/s) for the reciprocating cutterbar from a rice combine were tested. The results showed that the knife velocities of the reciprocating cutterbar from a rice combine at 0.55 m/s and 0.70 m/s on the three above mentioned forward speeds had an excellent cutting property. But the knife velocities of the reciprocating cutterbar from a rice combine at 0.33 m/s and 0.38 m/s only on the forward speeds 0.52 m/s had an excellent cutting property.nother result showed that the max net torque requirement of the reciprocating cutterbar from a rice combine during the cutting operation had a linear relation with the knife velocities. Torque and power requirements during the cutting operation had an exponential relation with the ratio of velocity. If the velocity ratio increased, the torque and power requirement also increased.he conclusion from this study is that the reciprocating cutterbar from a rice combine is better for plucking happy trees’s leaves.
Subjects
cutting device
Torque
ratio of broken branches
ratio of velocity
SDGs
Type
thesis
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