液压驱动链锯在采伐技术装备上的应用

介绍了液压驱动链锯的结构特点及其在采伐技术装备上的应用。     

油锯冷启动探讨

从理论上探讨了可燃混合气及火花塞电极、周围介质和温带等因素对油锯低温启动性能的影响,为进一步解决这一问题提供了理论依据.     

油锯安全标准中锯链制动性能测试方法综述

通过对油锯安全要求国际标准和国内标准的概述与分析，阐述了油锯锯链制动器性能的测试方法及测试结果的判定要求。     

油锯选型中的几个问题

本文就油锯的选用与自然、资源、油锯本身特性之间相适应的问题进行研究探讨。     

Productivity and cost analysis of semi-mechanised and mechanised systems on the Viphya forest plantations in Malawi

At least 200 000 m³ of timber is harvested annually using semi-mechanised harvesting systems on the Viphya forest plantations in Malawi. Although these systems have long been used on the Viphya, no investigation on their productivity has so far been reported. Additionally, the absence of localised productivity analyses in Malawi has created a paucity of information on appropriate timber harvesting systems for production maximisation and cost minimisation. The objective of this study was to compare the production rates and operational costs of chainsaw/grapple skidder (semi-mechanised) and feller-buncher/grapple skidder (mechanised) harvesting systems in order to determine the economic feasibility of mechanised systems in the Viphya forest plantations. The study was conducted in Pinus kesiya compartments at the Kalungulu and Champhoyo forest stations of the Viphya forest plantations. A work study approach was followed to capture harvesting time and volume data for the semi-mechanised system. Secondary work study data were used to simulate productivity of the mechanised system on similar compartment conditions. A timber-harvesting costing model was used to analyse the results. The study showed that the simulated mechanised system was associated with lower operating costs and inventories with higher production rates than the semi-mechanised system. The cost marginal difference was US$0.89 m^–3. It was therefore established that migration to mechanised systems could optimise timber harvesting productivity on the Viphya in future, if optimal volumes are available to ensure the efficient application of the mechanised harvesting system.     

油锯采伐作业中身体稳定性的生物力学分析

在进行油锯采伐作业时,油锯手身体稳定性的好坏,既会影响作业效率和疲劳程度,又会影响人体的安全性,而稳定角是衡量身体稳定性的重要指标。从生物力学的角度出发,对进行油锯采伐的作业人员进行受力分析,列出静力学方程以及力矩方程。设计实验方案,模拟油锯伐木作业过程,借助实验过程中测得数据,分析采伐作业时不同操作幅度下身体稳定角的变化趋势。研究结果表明,稳定角会随着重心偏移发生变化,当达到某一临界条件时,身体稳定性达到最好。     

新旧版便携式油锯安全要求国际标准分析与研究

通过对2011年最新版便携式林用油锯安全要求ISO 11681-1和2011年版便携式修枝油锯安全要求ISO11681-2与其上一版本的对比分析,归纳了新旧版国际标准变化的主要内容,并建议尽快修订我国与此对应的国家标准。     

采伐联合机专用液压驱动链锯马达类型的优化选择

综合分析了齿轮式、叶片式、柱塞式液压马达的特点及工作原理,优化选择确定斜轴式轴向柱塞液压马达作为采伐联合机专用液压驱动链锯马达。     

锯链传动片疲劳试验失效分析

国产锯链在高速空载疲劳试验时出现早期损坏,其寿命比同型号的OREGON锯链短很多。通过化学成分、金相组织、表面硬度及零件制造精度的检测对比分析,认为这是由于国产锯链传动片、连接片和切齿片的制造精度不高,实际孔距尺寸偏大,使得锯链节距大于链轮分度圆节距。这时锯链与链轮的相互位置关系就无法保证,锯链与链轮的啮合状况变坏,传动过程中将产生冲击、滑移窜动、爬高、张力波动等现象,使锯链的负荷成倍增加,尤其是传动片清理齿齿尖部位承受长期反复的冲击载荷,从而导致早期疲劳断裂。提高零件制造精度后,锯链与链轮的啮合状况正常,高速空载疲劳试验寿命达到要求。     

多参数动态测定油锯锯切生产率的方法

油锯锯切生产率的测定多为人工操作,很难控制最佳工况,精度较差,本文提出了多参数动态测定的新方法,这种方法用特制的传感器,配合微机与处理机,在不断改变各种锯切参数下,一次性地获得最大锯切生产率及其各参数的优化组合。