桉树爬树修枝机的设计与测试

为了实现快速修枝,结合桉树的通直度较其他林木高的特点,设计一种以两个对置分布的驱动轮作为攀爬驱动机构,从而使自身可以沿着树干直接往上爬升的爬树修枝机.该爬树修枝机主要由攀爬装置和修枝装置组成.对攀爬装置进行动力学分析,确定了驱动轮与树干之间的摩擦系数和攀爬装置夹紧力所要满足的关系式;根据滑切切割可降低切割阻力的原理,对...

Design and experiment of pruning machine for eucalyptus trees

In recent years the requirement of eucalyptus wood quality in the wood market is becoming higher and higher because the eucalyptus wood is now widely used as sawn timber rather than paper timber before.In this situation,the eucalyptus wood with high straightness and no knots can be sold at a higher price than the ordinary one.The forest owners usually can obtain high-quality wood with high straightness and no knots by pruning the branches of a living tree in the process of forestry production.However,the pruning work is mainly carried out manually and has a low efficiency because the existing pruning machines cannot meet the requirements of pruning work for eucalyptus due to their heavy weights or low operation efficiency.For the purpose of achieving a higher pruning efficiency,a pruning machine for eucalyptus trees was designed in this study.This pruning machine was designed based on the situation that the trunk straightness of eucalyptus is higher than that of other trees and is composed of a pruning device and a climbing device.Based on the dynamic analysis of the climbing mechanism,the condition that the friction coefficient between the driving wheel and the trunk was established,and therefore the condition that the clamping force of the climbing device must be met.The pruning device was designed for a purpose of reducing the pruning resistance based on the theory that the increase of the cutting blades’ inclination is conducive to reduction of the cutting resistance and the angles of the fixed blade and moving blades were determined to be 10°and 12°,respectively.The pruning machine’s climbing performance was tested on eucalyptus living trees and its pruning performance was tested on an equipment that used a round steel tube as a simulated trunk.Results showed that the pruning machine could climb a eucalyptus living tree smoothly without any damage to the trunk under the condition that the electromotive handspike’s force was 600 N.The pruning machine’s slipping rate was only 10.03% and it could cut the branches with a diameter less than 10 mm.By theoretical calculation and analysis,we can know that pruning machine’s acceleration was 2.88 m/s²,the climbing speed 2.97 m/s,and the power 603.10 W in the process of pruning.It is needed to increase the clamping force of the climbing device when the branches have a larger diameter.And the electromotive handspike’s force must be at least 1 573 N when the force between the moving blade and the trunk is zero.In that situation,the power consumed by the pruning machine will be 1 585.73 W.