用新型试验方法测定锯链的锯切效率

介绍了用于测定油锯锯切效率的一种新型试验方法和专用锯切试验机，并用该专用锯切试验机对德国STIHL锯链、美国OREGON锯链及国产JL10型锯链的锯切效率进行测定。该专用试验机采用恒进锯力进锯方式，且锯口面积的取值与锯切时间的测量保持了良好的一致性，从而提高了锯切效率的计算精度。该专用锯切试验机结构紧凑、进锯机构摩擦阻力小，测定精度高，重复性好，适用范围广。采用这种试验机测定不同锯链的锯切效率，可比性强。     

便携式链锯锯切生产率试验台的研制

详细介绍了南京林业大学最新研制的YQ-40型试验机的结构组成和工作原理，并提出了相应的锯切生产率测试方法。     

硬木锯机的相应锯路和锯切偏差值

在管理、维护和设计制材厂时,需要有关锯机的制材效率的信息.原材料的费用为整个制材厂生产费用的75%以上,因此,合理地选用锯机,使原木锯成板材的浪费最小,在经济上是非常重要的.锯路宽度、锯切偏差和表面粗糙度.是影响锯机制材效率的主要性能.锯路宽度决定了原木锯成     

屑片厚度和锯切宽度对锯切指标的影响

屑片厚度、锯切宽度对纵截圆锯锯切指标影响的试验研究尚不多见。本文在切削速度不变的条件下进行了变屑片厚度、变锯切宽度试验,得出了切削力P、锯木功率N、锯木生产率S以及锯切比功K分别随以上二因素变化的试验曲线和回归公式,为纵截圆锯锯切理论的研究,提供了一定的参考。     

木材锯切技术的发展

简述木材锯切技术所经历的手工期、简单机械期、近代期和现代期及其特点,对各种木材锯切技术进行了分析,结论是零锯料角木工锯子技术整体性能较好,可以实现高质量、高效率、高效益锯切木材.     

锯片锯料角对锯切表面粗糙度影响机理分析

分析了锯料角影响锯切表面粗糙度的机理，阐述了锯料角与锯料量对锯切表面粗糙度的影响。分析结果表明，只要锯料角不变化，则锯料量的变化对锯切表面粗糙度不起任何作用。锯料角影响锯切表面粗糙度的机理为开发新型锯片、提高锯切表面的质量和锯切效率提供依据。     

锯切表面粗糙度的综合评价

为了提高木材锯切表面的加工质量，探讨了微观不平度十点高度Rz在评价锯切表面粗糙度方面的可行性，并提出综合使用Rz和Ry两个参数来评价锯切表面粗糙度更加合理。     

WINTERSTEIGER公司迎接薄锯路锯切技术的未来

WINTERSTEIGER公司30余年来在精密薄锯路锯切领域获得成功,在全球销售了1500台薄锯路带锯机。     

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。     

木材锯切表面粗糙度二维分析与三维分析对比

使用传统的二维轮廓测定方法,测量木材锯切表面粗糙度准确度不高。利用三维表面轮廓成像技术测定木材锯切表面粗糙度,可获得较为准确的检测值和更真实的锯切表面微观形貌。     

柴油燃烧室外预热对发动机性能的影响

采用自制简易电控恒温燃油预热装置将柴油预热,在不同的预热温度对柴油发动机进行动力性能测试。实验结果表明,发动机在负荷特性试验时,预热后燃油消耗平均下降0.7%-3%;发动机在速度特性试验时发动机的动力性平均提高0.7%-1.1%,燃油消耗率平均下降5.9%-7.9%。     

LQ-18型锯链切削性能试验台研制

评定锯链的切削性能包括切削阻力、锯切功率、锯切效率以及锯链运转的平稳性等指标。这些指标的测定依赖于可靠的锯链切削性能试验装置。本文在现有LQ—11型锯链切削试验台的基础上,分析总结经验．结合计算机技术、测试技术,设计出性能更加完善的LQ-18型锯链切削性能试验台。该试验台采用了进给速度及链轮轴无级调速的运动形式,能够同时测量三向切削力、驱动链轮轴转矩、转速及进给速度,并且由计算机组成的测试系统直接测量、显示计算测试数据,生成测试报告,提高测量精度及测试效率。该专用锯切试验台结构先进,测试范围宽,测定精度高,重复性好。     

PT泵试验台的流量数字化控制研究

针对量油系统误差大的情况下PT燃油泵试验台现存的问题，探讨研究了微机与金属管浮子传感器和单片机组成测定装置，以代替用玻璃浮子量油的传统PT燃油泵试验台，并对其工作原理、关键技术进行了分析与研究，以便使我国在试验柴油机PT泵总成的过程中走出新的路子。     

A review on wood machining: characterization,optimization, and monitoring of the sawing process

ABSTRACT

Sawing is the most common machining process and is present in both primary and secondary wood transformation sectors. The objective of this paper is to review how it is affected by different factors. The current challenges associated with various machining factors, process monitoring, and sensor selection were identified and explained. Consequently, four research challenges and technological gaps were outlined. (1) Contradictory results have been reported due to different cutting processes, wood species, measurement methods, and cutting speed range studied in literature, so special consideration needs to be taken when comparing results with those available in the literature. (2) Laboratory test conditions cannot yet fully represent the extreme cutting conditions in sawmills. More emphasis should be placed on those harsh industrial cutting conditions. (3) Research on wood cutting lacks multi-objective optimization approach, which suggests that sawdust generation should be simultaneously analysed with surface quality and power consumption. (4) Compared with metal cutting, little research has been conducted on wood sawing monitoring using an artificial intelligence approach, which should be prioritized in designing adaptive control systems. Combining intelligent monitoring and multi-objective optimization approaches should pave the way for controlling the sawing process so higher surface quality and cost efficient machining is achieved.     

基于 AVR 的串口型燃油计量装置

基于AVR的串口型燃油计量装置采用称重流量传感器,通过液晶屏显示喷油器的流量值与经过实验测得的标准数据库进行比对来判断喷油量是否正常,并智能提示相关的处理措施。该装置可以应用到目前的各种测试仪器设备上,更加方便快捷的测量发动机喷油器的喷油量,提高目前国内传统检测的效率,在一些燃油测试与计量设备中可以得到广泛应用．使传统的一些设备具备完全数字化功能。     

高产脂马尾松优树自由授粉家系及其单株选择

根据《福建省地方标准(推荐)FDBT/LY1486脂松香综合标准》的要求,通过建瓯、龙岩两地的高产脂马尾松优树自由授粉子代林产脂力测定结果,发现在19~20年生的子代林中有5个单株的产脂力达到Ⅰ级特高产脂力(10 cm割沟单刀产脂量大于26 g),有11个单株的产脂力达到Ⅱ级特高产脂力(10 cm割沟单刀产脂量20~25 g),还有22个单株达到Ⅲ级普通高产脂力(10 cm割沟单刀产脂量15~20 g)。通过产脂力一般配合力测算结果,在24个家系135个单株的子代林中有11个家系38个单株的一般配合力呈正向效应。选用这些产脂力高的优株作亲本,建立无性系种子园或把子代林分改建成实生种子园,可以提高育种效益。     

数控微米刨切试验台的设计与试验

为解决传统热磨法加工微米薄木片及木纤维中高能耗、工序复杂、加工成本高的缺点,现改变加工方法,采用顺纹纵向刨切木材的方式,研发了数控微米刨切试验台。试验台主要由机架、纵向进给机构总成、工件夹具、控制面板、刨切机构总成、升降机构总成和限位机构组成,可对宽度为50 mm,长度为300～600 mm,高度为20～90 mm的木材工件进行纵向进给、切削量进给和刨切作业。笔者对试验台整机以及各机构进行设计,并通过ANSYSY对刀具进行强度校核。通过试验,确定刨切机构切削角δ取45°,刀刃伸出量h取0.05 mm,刀门宽度d取0.2 mm,刨得的木片平均厚度为18.7μm,最薄为15μm。最后通过显微镜观察发现经过刨切后的刀刃部分出现磨损,可通过表面改性提高刀具的耐磨性。     

The effect of rotation speed on the power consumption and cutting accuracy of guided circular saw: Experimental measurement and analysis of saw critical and flutter speeds

ABSTRACT

This paper investigates the effect of rotation speed and vibration response of a circular saw on the sawing process of Douglas-fir wood. An idling test was conducted on a guided circular saw to determine its stable operation speeds and vibration behavior. Short-time Fourier transform analysis was performed on saw idling test data, and variation of excited frequencies of the blade as a function of rotation speed was obtained. The saw blade critical speeds and the rotation speeds that correspond to saw flutter instability were identified. Then experimental cutting tests were conducted at different cutting conditions and the effect of rotation speed and saw vibration response on cutting power consumption and sawing accuracy was investigated. The results showed that conducting a saw idling test and vibration response analysis can identify the saw critical and flutter speeds, which is essential for identifying the optimum rotation speed of circular saw. There was a significant increase in power consumption when cutting at super-critical and super-flutter speed. The effect of rotation speed on sawing accuracy is complex and nonlinear. This effect interacts with feed speed, which makes it difficult to generalize sawing accuracy versus rotation speed in the circular sawing process.     

The impact of road geometry and surface roughness on fuel consumption of logging trucks

Fuel accounts for more than 35% of transport costs in Swedish forestry, and reduced fuel consumption would provide immediate economic and environmental benefits. The objective of this study was to quantify the effect of road gradient, curvature and surface roughness on fuel consumption of a conventional 60-ton logging truck. The study used a 320-km test track on both public and forest roads. The track was driven with various load weights in both dry summer and wet autumn conditions. Fuel consumption data were retrieved from the truck's CAN-bus system, and road data were measured with a profilograph. Average fuel consumption was 71.4?litres/100?km. A regression analysis showed that the most important factor was the interaction between vehicle weight and gradient, explaining the 86% increase between empty and fully loaded truck. In addition, the regression analysis quantified the individual effects of undulation, curvature and surface roughness, explaining the 107% increase in fuel consumption between the highest and lowest road class. Results from the proposed regression model (R² of 84% for a road section length of 1000?m) were consistent with predictions given by the European ARTEMIS model, and the proposed model can be used to improve cost estimation and route selection.