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对某家具厂电子七排钻所加工的三聚氰胺贴面板件进行加工时间和调机时间的测定与分析.研究表明,垂直与水平钻排单独作业或联合作业对加工时间影响非常显著,钻孔数目对调机时间的影响显著,随着钻孔数目的增加,平均单个孔位的调机时间呈下降趋势,但调机时间曲线趋于平缓. 相似文献
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分析了脱硝装置采用选择性催化还原脱硝(SCR)、还原剂为尿素的两台660MW机组两年内脱硝系统误退出的原因,结合火电厂脱硝系统设备、运行管理并和相关专业配合,提出了有效地解决方案,减少脱硝系统误退次数,进而减少氮氧化物的排放。通过观察解决方案实施后的脱硝系统的运行状况,可以明显地看到脱硝系统的误退次数急剧减少。 相似文献
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汪仁斌 《林业机械与木工设备》2003,31(12):44-45
在家具设计中,板件上会有许多孔位(如安装联接孔、定位木销孔等),如何快速而有效地画出并标注这些孔位,是家具设计人员面对的一个难题。传统的方法是:先一个一个地画好不同类型(如不同大小,不同深度、不同功用)的孔位,再进行多重复制;当所有的孔位画好后,再一个接一个地标注;标注时,需要先画出带有箭头的线,然后再输入标注文字,再复制和修改文字。采用这种传统的方法,绘图速度极慢,尤其是当板件上的孔位变化大和种类多时,问题就更为突出。笔者多年从事家具设计及AutoCAD教学,总结了一些绘图方法,可大大提高板件孔位的处理速度。这种方法不… 相似文献
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介绍了由组态软件控制的工控机和PLC组成的上下位机调施胶的网络监控系统,给出了监控系统的硬件组成原理、软件结构、工艺控制流程和具体实现方案。 相似文献
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近几年,由于定制家具能够很好地适应不同的家具使用空间和满足使用者个性需求,因而得到飞速发展,定制家具的个性化与多样化也对其没计与制造提出了更高要求。孔位的设计与加工是定制家具生产中一个复杂的环节,笔者打破传统板式家具结构孔位的设计方式,提出了新的孔位结构形式,优化了结构孔的设计,极大地提高了生产效率,为定制板式家具设计与制造提供了一种新的设计思路。 相似文献
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为确定板式家具安装重载滑轨时所需自攻螺钉的数量及其安装位置的最优排布方案,采用有限元法对滑轨连接强度进行数值模拟,探讨在滑轨关闭和完全打开两种状态下使用不同数量自攻螺钉和不同孔位安装方案节点的连接强度,并以理论计算值验证其结果。结果表明:以2个螺钉在1、9孔位固定滑轨两端,在滑轨关闭时节点结构可满足要求,在滑轨完全打开时旁板螺钉孔处发生破坏;以3个螺钉固定滑轨,对比不同安装位置的4种方案,以1-2-9安装方案即在距离前端1孔位32 mm处用自攻螺钉加固连接节点的强度为最优,与2个螺钉安装方案相比旁板螺钉孔处的最大等效应力减小50.9%。该研究为板式家具滑轨安装时螺钉数量及其位置的选择、孔位的设计提供参考。 相似文献
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介绍了一种挖坑机主轴部分的减振装置,其外形小,结构简单,能从主轴处直接降低振动,可有效地减少振动的向上传递,降低主轴部分振动对工作人员及其他机械部件的影响. 相似文献
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开展航空护林工作之初,租用的飞机来自民航一家。八十年代,随着改革开放的深入,航空护林租用的飞机来自民航、地方航空公司和部队三家。分布的范围比较广,最远的有山东青岛航空公司、三联航空公司、河北的邯郸航空公司。近几年,从供机单位调到航空护林基地的飞机调机时间过长,须进行改革。1产生调机时间过长的原因和影响开航前,飞机从航空公司基地调到护林航站,飞机上没有航站的观察员随机,机长为了本公司的利益,报给航站的调机时间往往偏多。例如,1999年秋航,一架到幸福航空护林站执行任务的M-8飞机调机航程为1847… 相似文献
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中密度纤维板调施胶控制系统的设计 总被引:2,自引:0,他引:2
苏永涛 《林业机械与木工设备》2005,33(1):31-32
介绍了中密度纤维板调施胶控制系统的设计思想,分析了中密度纤维板调施胶控制系统中由组态软件支持的上位机和以PLC为主体下位机的应用和特点,同时还分析了在系统设计中存在的不足。 相似文献
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[目的]针对木材蛀干害虫羽化孔洞缺陷检测问题,通过对声发射信号的时频分析,研究木材蛀干害虫羽化孔洞缺陷的AE信号特征.[方法]首先,对无孔洞和3种不同尺寸的钻孔缺陷的木材试件,参照ASTM-E976标准采用铅芯折断方式产生AE源,通过采样频率为500 kHz的2通道木材声发射信号采集系统获取原始AE信号.然后,对原始A... 相似文献
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阐述了指定位置钻孔组合机床中主轴箱体的设计,包括主轴箱体结构形式的选择、传动系统的设计计算及对传动零件进行校核,设计出主轴箱总装图,为钻孔组合机床的整体设计打下基础。 相似文献
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Tomasz Weso?owski 《Forest Ecology and Management》2011,262(9):1846-1852
Woodpeckers, able to excavate holes in trees, can provide resources critical for non-excavator hole users. Supply of woodpecker-made holes in forests depends on excavation rates by the birds and holes’ persistence times. I use 30 years of data from a primeval forest (strictly protected reserve, Bia?owie?a National Park, E Poland) to determine how long woodpecker-made holes persist, and whether their persistence varies across forest types, tree species and conditions, and woodpecker species. I followed the fate of 719 breeding holes, excavated by eight woodpecker species, for up to 27 years, from 1979 to 2010. Almost 80% of hole losses were caused by collapse of either the tree or the section supporting the hole. Holes were retained for (median) 6-7 years in riverine and oak-hornbeam forest but 10 years in coniferous forest. These differences can be explained by almost completely non-overlapping sets of tree species used in these different habitats. Lifespan of holes varied by tree species, ranging from four (Picea abies) to >22 years (Pinus sylvestris, almost 100% dead). The long lifespan of holes in the dead Pinus was exceptional, as otherwise, persistence was much lower for holes excavated in dead trees or limbs (5 years) than for those in living substrates (9 years). Tree species with higher frequency of holes in dead wood showed lower persistence times of holes. Lifespans of holes excavated by individual woodpecker species varied widely and was strongly dependent on frequency with which the species excavated in dead wood. Holes of Dendrocopos minor and Dendrocopos leucotos (only in dead wood) persisted for four years, while holes of Dendrocopos major (able to excavate in living sapwood of some trees) lasted for nine, and those of Dryocopus martius for 18 years. Retention of dead P. sylvestris, decaying Quercus robur in stands and addition/retention of aspens (Populus tremula and Populus tremuloides) in them would provide conditions to increase the availability of relatively persistent woodpecker holes in forests of the Northern hemisphere. 相似文献
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张素梅 《林业机械与木工设备》2008,36(7)
对现有的竹麻将席加工一体机中的局部结构进行适当改进,使其可直接对竹片的上下表面钻孔.主要介绍改造后竹片表面多孔钻孔装置的结构、工作原理及钻孔调整技术. 相似文献
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树洞是一种常见的树木腐朽现象,为了解树洞的研究现状和发展趋势,借助CiteSpace软件,对中国知网、万方、维普三大国内数据库截至2021年7月收录的期刊文献进行分析,并形成可视化图。结果发现:国内树洞研究在1957年进入起步阶段,21世纪后发展速度开始加快,发文量整体呈上升趋势,研究内容集中在树洞修补、树洞养护管理、树洞生物、巢箱设计、树洞周边愈伤木和森林空心树6个方面。同时,在此基础上依据关键词突现图分析发展趋势,结果显示:对树洞的研究在初期以森林生态系统为主,后期逐渐倾向于对树木的保护复壮和生态系统的维护,研究范围逐渐扩大。 相似文献
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Larvae of Apriona germari (Hope), found widely in China, cause serious damage to trees and are difficult to control. Since some biological control
methods have not been applied effectively in the field, chemical control methods are used widely. Because of low cost, no
poisonous residues and relatively safe application, zinc phosphide sticks have been tested to control the larvae as a matter
of urgency. However, there were no criteria about the dosage and use. Given the characteristics of larvae tunnels on triploid
Populus tomentosa trees and the one-on-one way of using poison-fumigated sticks, the larvae were treated by three treatments with zinc phosphide
sticks. The treatments are as follows: inserting one stick into the first hole of the tunnel from bottom to top (T1), inserting
a stick into each of the lowest two holes (T2) and inserting one stick into the first and third hole from bottom to top separately
(T3). We cleared the frass around the holes and on the ground before inserting the sticks and blocking every hole with mud
for each treatment. After the fourth investigation was carried out, the larvae of CK were still active, and had caused serious
damage and emanated fresh frass from old and new holes. Some larvae treated with T1 and T2 were in an intermediate state,
but all of the larvae treated with T3 died completely and their old holes had healed. The results show that inserting zinc
phosphide sticks (the extent of dispersion of the sticks was 20%) is a feasible method to control A. germari (Hope) larvae in triploid P. tomentosa of pulpwood trees. Because there were no statistically significant differences (p > 0.05) among the three treatments, we recommend that T1 should be used for economic efficacy. 相似文献
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超声波功率谱技术在木材空洞缺陷无损检测中应用 总被引:1,自引:1,他引:0
分析了不同孔径空洞的木材试件的超声波功率谱。阐述了功率谱的谱峰位置和谱峰高度与木材空洞大小之间的关系。分析认为,超声波在木材与空洞中传播时的散射不同,导致超声波在不同频率上的干涉,可能是造成上述现象的主要原因。利用该方法可实现木材空洞缺陷的无损检测。 相似文献