摘要
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,设计一种以两个対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,对修枝装置的切割刀片进行了设计,在综合考虑爬树修枝机的结构布置和总体质量的前提下,为减少修枝装置的切割阻力,确定其定刀片的倾角为10°,动刀片的倾角为12°;在桉树活立木和以圆形钢管作为模拟树干的试验装置上分别进行爬树修枝机的攀爬性能和修枝性能测试,结果表明:在攀爬装置所用的电动推杆推力为600 N的条件下,本研究所设计的爬树修枝机能够顺利攀爬桉树活立木,树干未见损伤,具有较好的攀爬性能,打滑率仅为10.03%,爬树修枝机能够切断直径10 mm以下的桉树枝条。结合爬树修枝机的结构参数和试验条件进行计算和分析可知,此时爬树修枝机的加速度为2.88 m/s^(2),最大爬升速度为2.97 m/s,修枝过程中所消耗的功率为603.10 W,而切断直径更大的枝条并且避免动刀片与树干之间产生作用力,则需要进一步增加攀爬装置的电动推杆的推力,推力至少为1 573 N,在此推力下,爬树修枝机消耗的功率为1 585.73 W。
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/s^(2),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.
作者
郑贤
邓毅
李岩舟
朱欣民
ZHENG Xian;DENG Yi;LI Yanzhou;ZHU Xinmin(School of Mechanical Engineering,Guangxi University,Nanning 530004,China;Guangxi Key Lab of Manufacturing System and Advanced Manufacturing Technology,Nanning 530004,China;Guangxi Pastoral Biochemical Co.Ltd.,Nanning 530007,China;Mechanics and Civil Engineering Institute,China University of Mining and Technology,Xuzhou 221116,Jiangsu,China)
出处
《林业工程学报》
CSCD
北大核心
2021年第2期148-156,共9页
Journal of Forestry Engineering
基金
广西制造系统与先进制造技术重点实验室项目(17-259-05S009)
广西科技重大专项(桂科AA18242011)。
关键词
桉树
修枝机
切刀倾角
攀爬测试
修枝测试
eucalyptus
pruning machine
inclination of cutter
climbing test
pruning test