谈固定造材锯的型式问题

在原条造材工序中,我国自1965年液压双园锯在柴河林业局诞生,继之液压平衡锯在壮志贮木场投产以来,采用固定式造材锯机造材已有十多年的历史。固定锯所具有的锯截大径材效能高、劳动作业条件得到彻底改善、易于实现造材自动化等优点,已为人们逐渐认识。为了充分发挥各种锯机的特性,改进造材质量,提高生产率和机械化、自动化水平,有必要就当前固定锯使用中的问题,对固定式造材锯的型式进行探讨,以利于新型固定锯设计方案的选择与确定。锯机类型的选择,首先需要掌握锯机加工地区森林资源的有关数据,了解原来的材积、直径、平均长度、生长素质等参数,     

零锯料角木工锯子的初步研究

从影响锯切功率的齿距、齿槽面积以及锯料量三个因素入手，对零锯料角木工锯子的切削性能进行了研究。分析了这三个因素使零锯料角木工锯子锯切功率降低的机理，并用有关实验加以证明。其结论是，在相同的锯切条件下，零锯料角木工锯子的锯切功率小于现有传统木工锯子。     

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     

日本制材工业概况

一九八四年随林业部考察组去日本考察制材工业,看过二十七个制材机械制造厂和木材加工厂。将考察情况概述如下: 总的印象是:日本的制材工业是以带锯机为主进行生产,甚至用带锯机做为毛边板的裁边锯。也有用多片园锯机做为主力锯进行剖料的。看不到使用框锯机再剖木材的。制材生产工艺基本是:湿法贮存木材(没有贮木池的贮木场,采取不间断的往楞垛上喷     

木工框锯机

框锯机又称排锯机、闯锯机 ,是将多根锯条张紧在锯框上 ,由曲柄 (或曲轴 )连杆机构驱动锯框做上下或左右的往复运动 ,使装在锯框上的多根锯条对原木或木方进行纵向锯切的机械。框锯最早出现在欧洲 ,由于生产工艺简单、操作方便 ,便于实现生产连续化、自动化 ,而被广泛地应用 ,特别在北欧的瑞典、芬兰和挪威 ,以框锯机为主锯机的制材占有相当大的比例 ,在前苏联及东欧的波兰和捷克等国家也一直是以框锯机为制材工业的主力设备。 70年代以后 ,瑞典、芬兰等国家对传统框锯机进行了一系列的技术改造 ,如提高主轴转速 ,增大进给速度 ,增加锯框的…     

竹单板锯制工艺技术

该文介绍了竹单板的锯制工艺技术、以及锯制竹单板的设备——小型精密框锯机的基本结构、传动系统等，比较了锯制工艺加工方法与其他加工方法的优缺点后，认为以复合竹集成材为基材、应用精密框锯机锯制技术生产竹单板是一种比较理想的工艺方法，它既简化了工艺程序、提高了单板质量，又降低了原料消耗、提高了竹材工业化加工的利用率。     

径切板生产工艺流水线的设计和布置

在制材生产中，为了满足某些特殊用途的需要（如出口泡桐拼板、乐器材和装饰薄木的刨切本方等），通常采用各种径切下锯法，以获得尽可能多的径切板材。由于下锯的方法不同，其径切板的出材率也不一样。为提高径切板的生产出材率和综合出材率，增加制材企业的经济效益，笔者在研究比较几种径向下锯模型［３］的基础上，选取效果较好的三开原木径切下锯法，对径切板生产工艺流水线的设计和布置进行了研究。１工艺设计的基本条件 本设计的任务是新建（或改建）一条年加工原木量为 ５０ ０００ｍ３的径切板生产流水线；计算选择所需的加工设备…     

框锯机进料装置的设计

框锯机具有加工规格性好、精度高、机械化程度高、工人劳动强度低等独特的优点，特别适用于将珍贵树种的板方材或人造薄木层积材等锯割成小规格薄板，用作木制装潢材料，如复合地板块、贴面板等的表层材料，以提高木制品的档次和产品附加值。但传统的框锯机存在生产效率低、表面光洁度差的问题。如何提高框锯机的生产效率和加工表面光洁度是决定框锯机能否推广应用的关键环节。提高加工表面光洁度可采用硬质合金镶嵌锯齿的锯条等措施解决，本文不多阐述。下面介绍一种可提高生产效率的框锯机进料装置。 众所周知，框锯机的锯切是通过锯条的…     

框锯机的应用前景

１概况 框锯机（又称排锯机、闯 锯机）是利用曲柄连杆机构带 动装锯框做上、下或左右往复 运动，由装在锯框上的多根锯 条对原木或毛方进行加工的 木工机械。由于框锯制材生产 具有其他制材机械生产无法 相比的优点，因而在世界各 地、特别是在欧洲地区得到了 广泛的应用。 框锯机与我国常用的带 锯机相比具有以下优点： ①在开档范围内可按板 厚要求安装多根锯条，一次可 得到多块所需厚度的板材； ②锯材规格质量好，精度高； ③避免了多次定位、装卡、摇尺等操作程序，缩短了辅助工作时间，因而生产效率高； ④机械化程度高、劳动强度低…     

木工圆盘类锯机动态性能研究概况

分析了影响木工圆盘类锯机锯切性能的主要因素，多方面提出了解决国锯中动态稳定性的方法，提出了当前圆锯动态性能研究中急待解决的问题及解决方法。     

原木等级及径级对规格材质量及出材率的影响

选用不同径级和质量等级的兴安落叶松原木,采用毛板下锯法和四面下锯法加工规格材,并检测分析了不同等级规格材的出材率。结果表明,原木径级在26～28cm时,规格材出材率较高;原木的等级与径级,及下锯法与原木径级交互因素,对规格材的出材率有显著的影响。要提高规格材出材率,应根据规格材尺寸优化匹配各因素。     

Application of the wood properties of large-diameter Sugi (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis>) logs to sorting logs and sawing patterns

The purposes of this study were to accumulate fundamental data on wood properties within large Sugi logs and to take applicable variations in wood properties into consideration for sorting logs and sawing patterns. The characteristics of basic density, moisture content, growth ring width, and microfibril angle (MFA) were measured and the relationship with log and lumber quality was examined. It was considered reasonable to estimate the lumber moisture content based on the moisture content of heartwood rather than that of whole logs, especially when producing large-sized lumber. The MFA reached a constant value before the 15th ring, and within a distance of 10 cm or less from the pith. Since the E _fr of lumber correlated with that of the log affected by MFA, it would be possible to produce lumber with a higher E _fr from the outer position of the log, based on selecting a log above the E _fr . Since the MFA would also affect the lumber warp, a sawing pattern avoiding the area around the pith or enlarging the rough sawn size when a large warp was expected could be effective in improving the lumber quality. To improve the lumber quality, not only one but also multiple wood properties must be applied to the sawing pattern.     

Multiple Period Combined Optimization Approach to Forest Production Planning

Recent efforts on the development of production planning systems for sawmills have focused on combined optimization type solutions in a steady-state market environment. This paper describes a linear programming-based multiple period production planning system which responds to expected changes in product value or market demand by changing policies with regard to sawing patterns and log consumption. Log and lumber inventories tie production periods together. The model was tested on a large log mill in British Columbia producing export products. It is shown that the model responds to market changes using sawing pattern selection and altered log consumption.     

下锯法对落叶松规格材出材率及质量的影响

分别采用毛板下锯法(SDR技术)和四面下锯法,进行兴安落叶松规格材锯解加工的试验研究.结果表明,四面下锯法加工规格材的出材率较高,且高等级规格材的得率亦高.通过分析对比两种下锯法加工规格材的优缺点,为规格材的工业化锯解加工提供技术依据.     

Variation in log quality and prediction of sawing yield in oak wood (Quercus robur)

Context

The commercial feasibility of sawmilling depends on the expected volume and value of sawn planks. Models that predict the volume of sawn timber of a particular quality and produced from logs of known characteristics are therefore very useful.

Aims

The objectives were to study variation in sawing yield and to obtain models that predict lumber volume and grade recovery on the basis of easy-to-measure predictor variables of saw logs.

Methods

Forty-six oak trees growing in Galicia (NW Spain) were felled and cut into logs. The logs were visually graded and sawn mainly into quartersawn planks, which were dried, planed and visually graded for structural purposes.

Results

The total volumetric sawing yield was 47.6 %. The sawing yield for planks of structural dimensions (cross-section, 70?×?120 or 70?×?170 mm) was 43.4 %, but decreased to 8.4 % for structural sized and quality grade beams because of wane and biotic damage in many pieces. Log grade did not significantly affect sawing yield in the sample analysed, despite the wide range of diameter over bark at the smallest end in the sampled logs (22–77 cm). The sawing pattern affected total sawing yield (F?=?4.913; p value?=?0.001) and the sawing yield for structural planks (F?=?6.142; p value?=?0.0002); radial sawing with one cut and live sawing of half logs provided the highest yields. Three models were proposed for estimating sawn volume in timber products, with the small-end log diameter over bark as the predictor variable and R _adj ² between 0.31 and 0.78 (p value?<?0.01).

Conclusion

For the purpose of producing oak timber destined for structural use, the presence of bark and sapwood in planks must be reduced in the sawing process; this would decrease the total lumber recovery but increase the timber value yield. Air drying must be accelerated to reduce biotic damage in sawn planks. Geometric mean diameter over bark at the smallest end (d) outperforms other measures as a predictor variable for total or structural sawn timber volume.     

原木裁板皮过程的建模理论与仿真方法

带锯制材的第一道工序就是裁板皮,数控带锯机的裁板皮过程必须进行软件设计,而软件设计的基础是数学理论的建立,提出板皮裁边的数控加工数学模型、仿真加工过程,为板材最优下锯提供计算机编程方程,为视频再现提供数学方法,为板皮锯切、板皮材积精确检测提供理论依据,为数字化控制提供理论.通过数控技术与现代制材工艺结合,将使传统木材加工工艺数控化,可以推进木材工业加工过程中计算机数学描述研究的发展,推进木材工业加工过程数学描述研究理论的开展.     

Experimental Study on Sawing Characteristics of Planted Eucalyptus grandis

INTRODUCTION Eucalyptus plantations have been important plantations in South China for its fast-growth rate. And the overall planted area is beyond 1.6 million ha, mainly distributed in the provinces of Guangdong, Guangxi, Yunnan, Fujian, etc. But, the main utilization is limited to wood chips currently. Along with the natural forest protection policy implementation, the wood resource has transferred from the natural forest to plantation forests, and the value-added application of plant…     

基于ANSYS的圆锯片模态分析和振动分析

利用ANSYS有限元软件,通过对圆锯片的模态分析,研究其低频范围的横向振动问题.通过软件分析得出圆锯片相应模态下的固有频率和振型.并利用动态信号测试分析系统对圆锯片相应模态的固有频率进行检测,得出圆锯片的固有频率与节圆数和节径数的变化规律,圆锯片边缘的位移矢量和与节圆数、节径数的关系,并指出在不了解圆锯片弹性模量、泊松比和密度等参数的条件下利用动态信号测试分析系统对圆锯片的模态进行检测具有一定的可行性.     

Difference in mass concentration of airborne dust during circular sawing of five wood-based materials

The object of this study was to compare the mass concentration of airborne dust during circular sawing of five wood-based materials: solid sugi (Cryptomeria japonica) lumber, tropical hardwood plywood, softwood plywood, particleboard, and medium-density fiberboard. Specimens were sawn at a constant feed per tooth (0.05 mm) using two saw speeds. The mass concentration of airborne dust of diameter 7.07 μm or less (respirable dust) was measured with a light-scattering dust monitor. The mass concentration showed a log-normal distribution, and the geometric means of mass concentration at saw speeds of 2000 and 3000 rpm were 2.33 and 2.89 mg/m³ for tropical hardwood plywood, 1.13 and 2.84 mg/m³ for particleboard, 0.91 and 2.28 mg/m³ for medium-density fiberboard, 1.09 and 1.38 mg/m³ for softwood plywood, and 0.32 and 0.66 mg/m³ for sugi lumber. The mass concentration for all five wood-based materials increased with the revolution speed of the circular saw.     

Determining optimal primary sawing and ripping machine settings in the wood manufacturing chain

for wood manufacturers around the world, the single biggest cost factor is known to be its raw material. Maximum volume recovery of this raw material is, therefore, of key importance for the industry. The wood products industry consists of several interrelated manufacturing steps for converting trees into logs and logs into finished lumber. Each operation usually optimises its functionality in isolation from the preceding and following operations. It is a well documented fact that the optimisation of decisions through the whole chain of operations is considerably more profitable than the optimisation of individual operations. The objective of this study was to determine the optimal machine settings for two interrelated operations, namely the sawing and ripping operations which have tradition? ally been optimised individually. A model, having two decision variables, was developed which aims to satisfy market demand at a minimal cost. The first decision was how to saw the log supply into different thicknesses by choosing specific sawing patterns. The second was to decide on a rip saw's priority value settings, which determines how the products from the primary sawing operation are ripped into products of a certain thickness and width. The techniques used to determine the machine settings included static simulation with the SIMSAW software to represent the sawing operation and mixed integer programming to model the ripping operation. A metaheuristic, namely the Population Based Incremental Learning algorithm, was used to link the simulation and mixed integer models and to determine the optimal settings for the combined process. The model's objective function was to minimise the cost of production. This cost included the raw material waste cost and the over or under production cost. The over production cost included the stock keeping costs and the under production cost was estimated as the buy?in cost of under supplied products from another wood supplier. The model performed well against current decision software available, namely the Sawmill Production Planning System package, which combines simulation and mixed integer programming techniques to maximise profit. The model added further value by modelling and determining the ripping priority settings in addition to the primary sawing patterns.