防错法在工装设计中的应用

传统的夹具设计通常考虑的是零件定位和装夹的可靠性,未考虑防错功能。加工某些零件时,因零件结构特点使装夹过程中存在一些不易识别或易被忽视的因素,从而造成零件即便错误装夹也能顺利完成加工。通过工装防错设计,采用一套装置或方法,将其加入工装设计步骤中,使作业者无法错误装夹。通过实例,剖析某专用工装的防错设计。     

细长支架零件铣削夹具的设计

针对细长支架零件使用通用夹具装夹困难,加工效率低等问题,分析支架零件加工工艺,设计了专用的夹具,一次装夹可以同时进行多个细长支架零件铣削加工。通过实践使用证明,该夹具能保证支架零件的加工精度,加工质量,生产效率大大提高,也为同类零件的夹具设计制造提供了依据。     

基于最大公共子图挖掘和装夹性能分析的夹具耦合设计方法

大量的夹具案例积累了可重用的经验和知识,为新零件实现夹具设计提供了理论基础和决策参考,而准确的夹具检索和合理的装夹判断是成功完成夹具设计的核心与关键。为此,根据零件B-rep表示的实体模型,通过特征之间的几何拓扑关系构造零件的标号图。结合标号图的线性顺序性,提出了标定索引值的DFS词典序原则,建立了最小DFS编码的遍历方法。其次,在挖掘出零件最小DFS编码的基础上,依据边编码中特征值、属性值及特征之间的连接关系,提出零件之间最大公共子图的挖掘方法,通过定义零件相似度和库相似度两个概念,构造出相似夹具检索和排序的决策因子。最后,通过建立定位确定性和装夹稳定性分析算法,依据决策因子大小逐一评估夹具对新零件的合理装夹,直至通过装夹性能的检验,完成夹具的设计过程。由于与零件一一对应的最小DFS编码,其搜索方法为图论中用递归容易实现的经典算法,而装夹性能评估只涉及点的坐标和法矢量信息,则属于可编程实现的离散型问题,故提出的"先检索排序夹具,后验证装夹性能"的夹具耦合设计方法,不仅能丰富和拓展计算机辅助夹具设计方法和理论,而且还将大大促进计算机辅助夹具设计系统的实用性。     

轴铣削平位工装设计

对轴类零件进行铣平位实例分析,解决装夹轴类零件铣平位问题,并根据现有的设备及工艺技术,解决既有加工难点,设计了两套轴类零件铣平位的工装夹具和一套钻模的工装夹具。该工装制作简单、成本低、装夹使用方便,加工零件质量可靠,大大提高了加工效率。     

一种链板式零件的气动可调铣削夹具

介绍了一种链板式零件专用夹具的设计过程,主要针对在铣床上加工薄壁型并且具有通孔的零件,对工件的孔心定位方法以及对工件形状和装夹问题进行了详细的分析和说明,设计了一种该类异形零件的专用夹具,实现了该类异形零件的装夹和定位;采用静力学分析方法研究了工件在夹具设计中是否满足加工要求,通过对变形云图和应力云图的分析,找出最优设计方案。该夹具定位准确、装夹便捷,并且具有良好的经济效益。     

一种轴类零件磨齿快换夹具设计与应用

设计了一种适用于轴类零件的新结构快换磨齿夹具,涨紧间隙更大,夹具通用性更高;根据不同零件更换系列化的快换涨套,可实现快速换产;通过设计大行程的中心活顶尖引导零件装夹,解决了自动化生产时工件装夹容易错位问题;该新结构夹具方案已验证可行并在大批量生产中推广应用。     

智能夹具系统减少成本

在精密零件的大批量生产中(特别是在汽车工业中),减低零件的装夹费用是非常重要的。在零件装夹中,必须人工安装每个零件,更换零件的速度慢且费用高。Unova公司下属的Lamb Technicon加工系统分部已开发了一种智能夹具系统(IFS)。该系统提供通用的选择,而不是为每个零件设计一种专用夹具。每种IFS可以     

薄壁盒形件真空吸附装夹变形的计算方法研究

为了较为准确地预测薄壁盒形件的装夹变形量,研究了不同误差形式下薄壁盒形件的真空吸附装夹变形趋势,设计了装夹变形数值求解和有限元仿真求解的具体流程,形成了比较完整的薄壁盒形件真空吸附装夹变形求解算法,通过实例验证了本方法的有效性,并为盒形类零件的装夹变形分析提供理论支持,为装夹误差控制及夹具设计提供参考。     

一种塑料薄壁壳体零件装夹方案的设计

针对某产品中塑料薄壁壳体零件加工遇到的装夹难题,设计了一副仿形铣夹具,并通过在壳体内腔中浇注石膏填充物,提高了零件装夹时的整体工艺刚度。介绍了装夹设计的思路、基本原理及技术要点。     

薄壁类小型回转结构件的模块化气动夹具设计

小型回转类薄壁零件的铣削加工,在加工中心上一般采用三爪自定心卡盘直接夹紧或通过衬套夹紧,该装夹方式装夹精度低,装夹完零件后需要重新校正坐标系,并且由于夹紧力为线接触或点接触,容易造成零件变形,从而影响零件的加工质量及效率。采用弹簧卡头夹紧技术,可以改善装夹状态,减小零件的装夹变形,根据零件成组技术、模块化技术和自动夹紧技术进行夹具设计,可达到精益生产目标。依据成组技术对零件进行分类后,根据被加工零件夹持部位的直径选用对应的弹簧卡头,并利用切削力计算出所需夹紧力,从而选择合适的气缸型号,实现了薄壁类小型回转结构件模块化气动夹具设计,经过生产现场的实际应用,提高了零件的加工质量及效率,降低了生产成本和劳动强度。通过对夹具方案的拓展应用,设计了多工位的模块化气动夹具,进一步提升了加工效率。     

SFEF-C超临界流体萃取分馏仪

由于现在能源需求越来越广,渣油和其它石油重质油的深度加工,对合理利用石油资源有非常重要的意义,重质油的性质、组成、结构研究对确定合理的加工方案有重要的指导作用,但由于重质油是非常复杂的混合物,必须加以分离,才能深入研究其化学组成和结构.所以我们设计了SFEFC超临界流体萃取分馏仪用来对重质油进行分离.     

Heads you win,tails you lose: filtration processing for the microscopical examination of sperm heads

The sperm head plays a key role in many fertilisation events and determining the precise location of molecules within the head region is important in mechanistically dissecting the fertilisation process. Such molecules may be present in low copy number and many sperm head profiles must be examined to localise them to particular subcellular structures with confidence. Filtration has traditionally been used for the purpose of concentrating biological material, such as free‐living cells, spores, and subcellular fractions, and little attempt has been made to extend the procedure to encompass the entire processing schedule, mainly due to the incompatibility of intermediate dehydrating solvents with membrane filters. The novel and simple technique of filtration processing that we describe produced a dense mat of cells, with several sperm heads being visible in coronal orientation in a high‐power field at the light microscopic level, and allowed positive immunocytochemical staining to be identified with confidence. This new technique exploits the low viscosity of LR White acrylic resin to allow the entire processing procedure to be undertaken in the filtration apparatus. In contrast, conventional techniques for preparing free‐living cells, namely pre‐embedding in a supportive matrix prior to processing, and centrifugation at each stage of the processing procedure, proved suboptimal, partly due to the final concentration that could be achieved, but mainly due to the random orientation of cells that these techniques afforded.     

一种泡沫柱中气泡特性的测试装置

介绍了采用光－电原理测试泡沫柱中气泡特性的装置。采用两对红外发射对管作传感器，数据采集采用单片机，一次可采集１００００个气泡。通过计算机进行数据处理，可获得气泡的平均直径、气泡分布、含气率及气泡密度。用该装置测试具有迅速、准确、适应范围广的特点。     

血液流动性的计算机可视化测定及其技术应用

简要描述了日本MCFAN研究所生产的血液流动性可视化检测仪的测定原理、实验方法和临床应用。血液流动性的可视化测定仪（以HR300型为例）将进样系统、计算机处理系统、显微摄像等一体化（Micro Channel Array Flow Analyzer,MCFAN）,使操作繁琐的血液流变性观察检测变得简便易行,并通过液晶显示器可观察到血流的状态,具有直观形象的特点。广泛用于预防医学、药物研究、疾病诊断和健康教育等领域,并为大众健康咨询提供了直接支持,本文比较全面的介绍了血液流动性的检测方法及其临床应用。     

Improving Operational Reliability by Means of Artificial Intelligence

A new approach to ensuring operational reliability is proposed. In this approach, three conditions for ensuring operational reliability must be satisfied. A mathematical apparatus for calculating the reliability of such structures is developed.     

Localization of glycosylation sites in the golgi apparatus using immunolabeling and cytochemistry

This review summarizes data on the distribution of certain glycosylation steps in the Golgi apparatus as revealed by immunolabeling and lectin techniques. The methodical basis for such investigations was provided by the introduction of the colloidal gold marker system for immunolabeling and the development of new means of tissue processing such as the low-temperature embedding technique using Lowicryl K4M. The application of these techniques together with highly specific antibodies has provided much of the basis for our current understanding of the Golgi apparatus in functional terms. Thus, in many cell types, three Golgi apparatus compartments can be distinguished, whereas in others no such functional subdivision is evident. Investigations on sialyltransferase distribution have also provided direct evidence that GERL is structurally and functionally part of the Golgi apparatus.     

The practical histochemical demonstration of catecholamines by formaldehyde-induced fluorescence

Catecholamines become intensely fluorescent when exposed to formaldehyde. This is due to closure of the side chain by a methylene bridge and subsequent dehydrogenation, which results in the formation of intensely fluorescent isoquinolines. Exposing freeze-dried tissue to formaldehyde vapour makes it possible to study the distribution of catecholamines by fluorescence microscopy. The present paper deals with the practical performance of the formaldehyde-induced fluorescence. The technique consists of the following steps:

• 1 Freezing. This must be rapid. An apparatus is proposed for freezing at maximum rate, in which the tissue slice comes into sudden contact with a cold metal surface.
• 2 Drying. The tissue must be dried at a temperature below ?40°C, using an efficient apparatus. The types of apparatus are described and discussed. Small tissue pieces can be dried overnight with an efficient apparatus.
• 3 Formaldehyde condensation. Formaldehyde is generated by warming paraformaldehyde powder in a glass vessel containing the freeze-dried tissue pieces. The temperature of exposure and the water content of the paraformaldehyde powder must be properly adjusted for each tissue. Exposure for 1 hour at 50°C to paraformaldehyde powder equilibriated with 60 p.c. relative humidity is recommended as a start.
• 4 Embedding, sectioning, and mounting. The formaldehyde-treated tissue pieces are embedded in paraffin wax or, for better resolution, in epoxy resin. Sections must be spread on the slide without using water. Xylene, paraffin oil, and Entellan are suitable mounting media.
• 5 Fluorescence microscopy. Any microscope fitted with non-fluorescent optics is suitable for fluorescence work. A sufficiently intense light source is necessary; the high pressure mercury vapour lamp HBO 200 (Osram) is suitable. Special effects can be obtained with different filter combinations. The Schott filters BG 12 and OG 1 are suitable for most practical studies of catecholamines.

     

能量可控陡脉冲肿瘤治疗仪的研制

利用高强度陡脉冲对恶性肿瘤细胞的不可逆性电击穿的特点，将现代电力电子技术应用于高压陡脉冲发生器的设计中，研制了一套能量可控高强度陡脉冲肿瘤治疗仪及其计算机测控系统。仪器的脉冲频率、脉冲宽度和脉冲峰值独立可调，从而实现了对输出能量的控制，满足了肿瘤治疗离体实验的要求，为进一步的肿瘤细胞实验和动物实验打下了基础。     

Trans-Golgi reticulum

The trans-Golgi apparatus reticulum is that portion of the Golgi apparatus located in the trans-most aspect of the stack exhibiting certain characteristic morphological and functional characteristics. The membranes of the trans-Golgi reticulum are reticular in form, thickened with plasma membrane-like characteristics and with a considerable portion of their surface covered by clathrin coats. The enzymes thiamine pyrophosphatase and sialyl- and galactosyl transferases are functional markers. Correlative studies show the trans-Golgi apparatus reticulum to be involved in glycoprotein, enzyme and receptor processing and sorting along multiple pathways. Sorting and transfer of constituents to lysosomes, to secretory granules, or to the plasma membrane emerge as dominant functions.     

液体磁性磨具光整加工的参数选择

液体磁性磨具光整加工技术是用磨具本身的流变特性对工件表面进行光整加工的新技术.在实际加工试验研究的基础上,分析了磁场强度、工件转速、加工时间工艺参数对加工表面质量的影响规律;为进一步研究液体磁性磨具的加工机理和加工装置的改进提供了依据.