环氧树脂填充胶用于大型冲压设备基础倾斜修复

环氧树脂填充胶用于大型冲压设备基础倾斜修复１１８００８辽宁丹东汽车制造厂设备分厂黄文龙５０００ｋＮ以上的大型冲压设备，对基础安装精度要求较高，其下横梁工作台面水平度国产机床允差０．２０／１０００ｍｍ，进口机床允差０．１０／１０００ｍｍ以内。如安装精度...     

美国减振技术公司弹性体或弹簧减(隔)振器技术公告

机械设备如冲压设备、锻锤、精密机床、纺织设备以及容器加工设备等,可以通过不同的方法安装在基础上.为了加快机器的安装以及车间设备布局灵活性,用户越来越多地采用设备无锚栓安装方式,该安装方式目前已有许多不同类型.如有的无锚栓安装方式具有简单的调平功能,有的则具有综合调平和振动隔离功能的减振垫.弹性体减振垫、钢质弹簧、气垫、毛毡、软木以及金属钢丝绳都是一些被用来做振动隔离的材料.隔振的效果尤其取决于减振垫材料的选取.而本技术报告将主要探讨具有综合水平调节装置的减振垫或仅用垫片调节水平的减振垫,其中这两种减振垫的材料是弹性体或钢质弹簧.     

百特 北京伟奇机械有限公司专业生产机床减振垫铁S78,S77,S79,BS,PS系列

我们提供给您的:机械设备减振安装,机械部件间减振连接。高品质的减振产品。良好的衰减和隔离振动。良好的改善车间环境噪音。您可以得到的:机床到位既可安装,立刻生产。缩短安装周期,节省安装费用。可使粗;精加工设备组成合理的生产单元,缩短工件周转路线。可随时根据工艺;生产需求,调整机床位置,减少二次安装费用。     

等径膨胀螺栓在大型机床安装工程中的应用

近年来国内外一些工厂中开始兴起采用整板基础、减震垫铁和膨胀螺栓安装机床。这种方法不需要在地基上预留或重新打方孔,只要在已浇灌混凝土的地基上钻孔即可,可以做到设备就位时即可开始调整安装精度,缩短了设备安装周期。本文介绍了膨胀螺栓的结构形式和模拟试验以及安装应用情况,图6幅。     

CW6163B卧式车床的改进

为了适用大回转直径备件的加工特点,对现有普通CW6163B卧式车床进行工艺改进,对工艺装置重新选型、改进机床刀架并对机床安装重新调试,完成后增大了设备加工能力和范围,取得较好的经济效益。     

连铸辊数控堆焊机床的研发

设计了一种新型的连铸辊堆焊机床,其具有自动化程度高、堆焊质量稳定的特点.本文介绍了该机床的主体结构,在现有机床机械部分的基础上设计安装了SINUMERIK801数控系统,并为埋弧焊机设计安装了具有双单片机处理器的数字化控制系统.     

蓄能器在机床与金属加工设备中的应用

分析蓄能器在机床与金属加工设备中的作用,列举典型例子说明蓄能器在机床与金属加工设备液压系统中改善系统性能的重要作用,同时论述蓄能器的使用方法和应用前景.     

俄罗斯龙门铣床PLC改造

我厂于1992年进口了一台俄罗斯龙门铣床,正常运行几年后电气系统主要是PLC部分故障频繁,由此影响了设备正常运行.最后一次故障致使设备停机长达两月之久.俄罗斯生产的PLC其硬件采用大插板总线槽开放式结构,其制造工艺粗糙,元器件抗老化抗腐蚀处理不过关,芯片与安装底板之间,插板与总线槽之间接触不可靠.机床生产厂家未配置PLC编程设备,一旦PLC内部出现故障,维修无从着手,仅凭维修人员的经验难以从根本上排除PLC内部故障.     

DE10电火花成型机床的电气系统改造与实现

通过对DE10电火花机床电气控制系统改造可行性的研究,提出采用单轴数控系统控制柜代替原有控制系统的方案,主轴电机采用T0818电机,并设计了其他部分控制电路.经安装调试,改造后机床已投入正常使用,且与原机床相比,电气系统的可靠性、可操作性、可维修性提高,系统经济灵活、性价比高.     

对废旧CA6140车床的改装

随着科学技术的发展,机床的发展速度也较快。但对原有的废旧机床进行工艺和装备的改造,使旧设备满足生产的需要,这样不仅造价低、上马快,而且还可弥补设备的不足,减少投资。１　改装设计利用废旧ＣＡ６１４０机床的床身,拆除尾座、刀架和小拖板,然后安装上铣端面钻顶尖孔结构（见图１）。在此机床上工件只安装一次,即可完成对轴两端面铣削和顶尖孔的钻削。图１　结构示意图２　工作原理铣两端面钻顶尖孔机构由两个刀轴箱组成,经传动轴将动力从左刀轴箱传给右刀轴箱,两刀轴箱底面有凹的山形槽,以此和床面上的山形导轨相配合定位,…     

阿那其根醇提取物对两种炎症模型作用机制研究

目的: 研究阿那其根醇提取物(EERAP)对二甲苯致小鼠炎症模型和脂多糖(LPS)诱导RAW264.7细胞炎症模型的影响。方法: 将50只小鼠,随机分为对照组(饮用水)、EERAP高剂量组(640 mg/kg)、中剂量组(320 mg/kg)、低剂量组(160 mg/kg)和阿司匹林组(120 mg/kg),采用二甲苯建立小鼠炎症模型,比较小鼠耳廓肿胀度及耳廓毛细血管通透性的变化,ELISA法测定各组炎症渗出液丙二醛(MDA)、超氧化歧化酶（SOD）的含量;LPS诱导RAW264.7细胞建立细胞炎症模型,ELISA法测定核转录因子kappa B（NF-κB）和肿瘤坏死因子-α（TNF-α）含量。 结果: 在二甲苯致小鼠炎症模型中,EERAP高、中、低剂量组均能抑制小鼠耳廓肿胀度,减少小鼠耳廓毛细血管通透性,减少渗出率,与空白对照组比较均有统计学差异(P<0.01);EERAP高、中、低剂量组均能降低血清中MDA含量（P<0.05）,显著升高SOD含量(P<0.01);在LPS诱导的RAW264.7细胞炎症模型中,EERAP在3.125～200 μg/mL范围内可降低TNF-α含量,而在2 μg/mL时也可以降低细胞NF-κB含(P<0.05),与阿司匹林组无统计学差异。结论: EERAP可能是通过抑制MDA、TNF-α和NF-κB的生成,升高SOD的水平,起到抗炎、抗氧化作用。     

Calculation of the parameters of pulsed laser welding of thin sheets of aluminium alloys

One of the main advantages of the MIG/MAG process is its high productivity. In most of the applications, positive polarity is used, due to its greater arc stability, generation of less splatter and formation of weld beads with suitable geometry. However, in some applications, there is a need for greater production capacity than that offered by conventional MIG/MAG welding. In the literature, it is stated that negative polarity provides a higher fusion rate than positive, despite leading to a high level of splatter and unsuitable formation of the weld bead. Unfortunately, there is not much information available on the effects of the process variables in this polarity, much less justification for such. Therefore, this work is an attempt to try to understand the reason why there is a higher deposit rate in negative polarity, as well as the related effect on the geometry of the weld beads. To do this, comparative MIG/MAG welds were produced in both positive and negative polarities, using two compositions of shielding gases at two current values. The transfer mode and the behaviour of the arc were analysed by synchronized profiling. The geometric profile of the weld bead was evaluated by means of metallographic procedures. From the results, which disagree in part with the current literature, it was seen that both the transfer mode as well as the morphology and the appearance of the weld bead are dependent on the composition of the shielding gas. To explain the phenomena inherent in the greater fusion rate of wire in DC ? , the suggestion is that the fact that arc scales the sides of the wire in this polarity may be the governing factor.     

Mechanism of improvement of formability in pulsating hydroforming of tubes

The mechanism of improvement of formability by the oscillation of internal pressure in a pulsating hydroforming process of tubes was examined. Free bulging hydroforming experiments of mild steel tubes under oscillating and constant inner pressures were performed. For a high constant pressure, a round bulge with local thinning was observed, whereas wrinkling occurred for a low constant pressure. The occurrence of these defects was prevented by oscillating the internal pressure in the pulsating hydroforming. In the pulsating hydroforming, a uniform expansion in the bulging region was obtained, and thus the formability was improved by preventing the local thinning. It was found from an observation of deformation behaviour, using a video camera, that the tube is uniformly expanded by repeating the appearance and disappearance of small wrinkling. The cause of the uniform expansion for the pulsating hydroforming was also interpreted from the variation of stress components. In addition, a similar deference in deformation behaviour between the oscillating and constant inner pressures was also obtained in finite element simulation.     

钛铁矿烧结性能研究

将钛铁矿在氩气及空气气氛中不同温度下进行烧结。采用XRD及热分析研究了钛铁矿在不同温度下烧结后的相组成及质量变化。结果表明,在氩气气氛950℃下烧结后,钛铁矿的物相组成没有发生变化;在空气中不同温度烧结后,600～800℃较低温度区间,钛铁矿转变为热力学亚稳定的Fe2Ti3O9,950℃以上烧结时,钛铁矿转化为热力学稳定的Fe2TiO5。钛铁矿的晶体结构由烧结前的三方结构经低温烧结后转变为亚稳态六方晶系的Fe2Ti3O9,950℃以上烧结后,晶体结构转变为斜方晶系的Fe2TiO5。     

BGA焊接技术的探讨

随着1C技术的不断进步,IC正在向着集成化、小型化、高性能、多管脚的方向发展,BGA封装形式在IC技术的发展中得到了广泛地应用,因此BGA封装的焊接技术越来越受到重视.本文主要根据BGA封装在回流焊接中出现的短路、虚焊、空洞、溅锡等现象,分别从PCB焊盘设计、器件保护、钎料选择及回流焊温度曲线的确定等方面进行了分析,并...     

Comparison of the effects of small additions of silicon or aluminum on the oxidation of iron-chromium alloys

A study has been undertaken of the oxidation behavior of Fe-26 wt.% Cr-1 wt.% Al and Fe-26 wt.% Cr-1 wt.% Si at 800° and 1000°C in oxygen, in order to determine the usefulness of the two tertiary elements in facilitating the development of the Cr₂O₃ external scale. The research has also permitted a comparison of the modes of internal oxidation of these elements, with a view to ascertaining the ease of establishment of the tertiary element oxides as healing layers at the scale/alloy interface. It has been shown that aluminum is the more effective addition in this respect, due to formation of a higher population density of internal oxide nuclei in the early stages. However, in the 1% Al alloy, the precipitates penetrate inward, to considerable depths, as continuous platelets, making development of a complete healing layer difficult. In practice, a higher aluminum concentration is necessary for the closely spaced precipitates to coalesce to form the healing layer, but the process then occurs rapidly. The initial internal oxide nuclei in the 1% Si alloy have a much smaller population density and are restricted to a location very close to the surface. Thus, a healing layer can be established, but the large interparticle spacing makes this a very slow process. Even at a higher silicon concentration, it takes a significant period to be completed. The effects are discussed and accounted for, particularly in terms of the relative stabilities of the various oxides.     

XPS characteristics of sulfur of bio-oxidized arsenic-bearing gold concentrate and changes of surface nature of bio-oxidation residue

During bio-oxidation of sulfides, the chemical state change of sulfur is a complex and key factor. It is not only an indicator of the extent and intensity of the bio-oxidation, but also controls the property of bio-leaching medium and the period of oxidation. The chemical state of sulfur in sulfides oxidized by leaching bacteria was studied with XPS. Sulfide minerals in the arsenic-bearing gold concentrate consist of pyrite, arsenopyrite, chalcopyrite, galena, sphalerite and so on. In order to probe the pattern of the chemical state change of sulfur in the bio-oxidation residue of arsenic-bearing gold concentrate, the structure of the grains, and the surface nature of the residue, XPS test was carried out through different sputtering duration. The study of XPS clearly shows that: sulfides is progressively oxidized from the surface of minerals to the core by leaching bacteria; the chemical valence of sulfur changes from S^2- or [S2]^2- to [SO4]^2- ; sulfur in the core is in a reduction state, S^2- or [S2]^2- , but exists in an oxidation state S^6 on the surface; due to the chemical state change of sulfur, mineral phase of the bio-oxidation residue is also changed(sulfides inside, while sulfates outside); the layered structure is found in the grains of the bio-oxidation residue.     

高等教育国际化与中国高等教育施化力培育

本文从化层、化型、化向与化力等方面考察高等教育国际化的应然本质属性 ,描述与分析中国高等教育在国际化潮流中表现出的发展态势 ,针对种种态势提出中国高等教育核心施化力培育战略 ,以使中国高等教育乃至世界高等教育真正地走向国际化     

基于事例推理技术在夹具CAD中应用的研究

通过对夹具在机械加工设备中的作用，夹具的设计过程，现代计算机辅助设计技术在夹具设计中的应用和事例推理技术的分析，提出了基于事例推理（CBR）技术的夹具半智能化设计系统的总体设计和夹具结构设计方案。     

ULCB钢焊接熔池凝固过程数值模拟

采用元胞自动机法建立ULCB钢焊接熔池凝固过程的宏微观耦合模型,模拟非均匀温度场下焊接熔池凝固过程的组织形貌演变和溶质场分布,分析不同形核参数和合金成分对焊接熔池枝晶形貌的影响。结果表明,熔池边缘形成柱状晶,熔池中心形成等轴晶,柱状晶和等轴晶相互抑制长大;枝晶生长过程中始终存在着枝晶偏析现象;形核密度和合金成分影响枝晶的形核和生长,随着形核密度和合金成分的增加,焊缝中等轴晶区域增加,晶粒细化。