机器人焊接挖掘机动臂工装结构设计及工作原理

通过介绍机器人焊接挖掘机动臂工装结构设计方案,较为详细介绍了焊接工装定位与夹紧方式及结构的设计及工作原理.该工装适应多型号动臂自动化焊接,节约了工装成本,实际使用中提高了生产效率.     

基于数字化测量的柔性工装调装技术研究

在飞机装配过程中,工装的准确度将会直接影响飞机的装配精度。工装的调装是飞机装配前重要环节之一,而柔性工装由于重复定位精度高等原因调装工作更为困难。为此,本文对柔性工装的调装技术进行研究,通过对工装调装方案介绍,应用了数字化测量设备规划与仿真技术并对坐标系拟合的原理与算法进行了研究和分析。结合柔性工装实例详细介绍了柔性工装的调装方法,为柔性工装调装提供理论依据。     

民用飞机装配生产线工装产能评估研究

对民用飞机装配生产线工装的总体情况进行了介绍,并对工装产能的评估进行了研究.在研究中,建立民用飞机装配生产线工装产能评估数学模型,对现有工装产能及扩充需求进行测算、评估,同时实现工装产能的量化评估,为工装资源的合理配备提供了重要依据.     

基于Pro/E的工装快速设计研究

实现工装快速设计是缩短产品生产准备周期的重要手段。在对实施工装标准化后企业的工装设计特点以及Pro／E软件特点进行分析的基础上,指出基于Pro／E建立工装参数化元件库、参数化典型结构库可以进一步提高工装设计效率。最后介绍了Pro／E基础上的工装快速设计实现。     

通用工装设计方法

本文主要涉及矿用刮板输送机产品生产过程中一些专用工装,介绍了这些专用工装的工作原理及设计方法,通过分析归纳总结,将专用工装改进设计成为通用工装,通过设计通用工装,降低了生产制造成本,也为通用工装设计提供了可借鉴的方法。     

面向工装的可定制柔性编码技术研究

结合工装分类的特点,分析了企业对工装编码的可定制、柔性化的相关需求,阐述了可定制柔性编码体系的组成结构,在此基础上建立了柔性工装编码,介绍了工装编码的解析流程,通过实例分析了该编码技术在工装管理中的应用。     

基于功能元的网络化工装信息管理平台研究

针对当前专业工艺员只熟悉自己所设计的工装,容易出现工装管理和设计"各自为政"的混乱局面,为了降低工装准备时问,缩短产品制造周期,提出建立基于功能元的网络化工装信息管理平台,实现工装信息的共享.介绍了工装功能元和功能元库的概念模型设计、工装信息管理平台体系结构设计及系统实现中的相关关键技术.     

快换隔水管母接头焊接用工装设计

介绍了隔水管母接头与主管的结构特点,焊接用工装设计的要求,焊接用工装结构以及工装的使用方法。     

一种新型动车组车体底架加工工装

为了改变原有铝合金车体底架加工工装影响加工效率、适用范围小等缺陷,设计制造了新型工装。介绍了该工装的结构组成、结构特点及其工作原理。     

齿轮工装CAD系统开发

介绍了一套适用于齿轮制造中工装的计算机辅助设计（CAD）系统。叙述了基于成组技术的工装信息描述以及自动生成工装全套零件图和装配图的方法。     

An improved transfer module and variable temperature control for a simple commercial cooling holder

A new cold stage transfer module was designed for the commercially available cooling holder of the JEOL JEM 100CX electron microscope. In the new CSTM the entire loading of the specimen is carried out under liquid nitrogen. This gives a frost-free transfer during which the temperature of the sample does not exceed 120 K. Straightforward modifications to the commercial cooling holder permit continuous selection of specimen temperature between 100 and 450 K. The sample can be heated or cooled at rates of up to 7 K/s. These modifications do not impair the resolution of the holder which is better than 1.5 nm. This work illustrates a relatively simple way of modifying a commercial cooling holder into a true cold stage system.     

基于夹具设计中定位销长度的分析

分析了机床夹具设计中，使用圆柱销作为定位元件时，定位销的定位作用及定位销临界尺寸的界定；论述了采用定位销定位时，定位销长度的设计选择对工件加工定位的影响。无论欠定位或过定位均会对夹具的定位精度产生影响，从而影响到工件的加工质量。     

一种新型实用的牵引驱动增速刀柄

研制了一种由特制的牵引剂进行驱动、用于回转机床的增速刀柄，该刀柄能使刀具增速8倍而不改变原机床的任何结构和主轴转速。刀具增速后达到磨削速度，可实现模具型腔的复杂空间曲面的精加工。使普通NC铣床代替磨床，并解决了工件在一次装夹中实现从粗加工到精加工的全过程。该刀柄体积小、结构紧凑、传动平稳、无噪声。     

Increasing the scanning speed of scanning tunnelling microscopes

The scanning speed and quality of images obtained with a scanning tunnelling microscope can be increased by replacing the tunnelling tip holder with an active, high resonance frequency piezoelectric positioner. The combination tip holder and positioner has a resonance frequency near 100 kHz, allowing fast closed-loop feedback control of the STM. With appropriate electronic shielding, the active tip holder can also be used to modulate the tip to surface distance at high frequencies for work function mapping. The high speed positioner is complemented by a ‘tip-saver’ circuit which senses imminent tip-surface contact, preventing tip crashes. The circuit, when driving the fast positioner, has a response time of under 20 μs and is not subject to the oscillation problems normally associated with closed-loop feedback systems operated at high gains and large signal bandwidths.     

A comprehensive approach to determining minimum cutter lengths for five-axis milling

Interference detection and avoidance by the shortest cutter for the five-axis milling machining is a critical task. Short tool length increases the rigidity and chatter stability of the cutter. In this research, a new and efficient method of interference detection and avoidance by the shortest cutter is developed. For the specific five-axis machine configuration, first possible candidate parts for the collision are found, which are complete cutting system (spindle, tool holder, and cutter), the work in process model, and the fixture. Spindle, tool holder, and tool are represented by the solid geometry identity of the cylinder, truncated cone, and cylinder, respectively, with the length and diameter as parameters. The surfaces of the work in process model and the fixture model are represented as the point cloud data of the suitable density. The Kd-tree data structure is employed on point cloud data which gives an efficient searching of the potential candidate points for the interference detection with the complete cutting system. All existing methods are able to detect the collision, but they are not capable to remove it with the optimum cutter length. The proposed algorithm has not only the capability of collision detection; it can also remove the collision with the optimum tool length. Other scope of the proposed algorithm is the selection of the tool holder to minimize the overhang tool length.     

考虑磁场区影响的电控永磁压边方法

电控永磁压边方法具有独立加载、传动链短、节能、易于控制等优点。针对铁磁性板材成形,提出了一种新的成形区和磁场区重合的电控永磁压边方法。以圆筒形件的拉深成形为例,采用新设计的压边装置对不同压边力加载条件下的结构变形进行了磁-力耦合有限元模拟,分析了板坯磁性对磁场和压边力分布的影响。由分析结果可知,新设计的压边力加载装置的刚度明显提高,新压边方法具有更好的压边效果,模具结构更紧凑。根据模拟和理论分析结果设计制作了拉深试验装置。实验结果表明,将成形区和磁场区重合的电控永磁压边方法是完全可行的。     

A hybrid NN-FE approach to adjust blank holder gap over punch stroke in deep drawing process

In deep drawing process, the blank holder plays a key role in adjustment of metal flow into the die cavity. Moreover, the quality of drawn parts is extremely affected by this flow. There are two methods of treating the blank holder in deep drawing and its simulation. One is blank holder force (BHF) and the other is blank holder gap (BHG), defined as the fixed distance between the blank holder and the die surface. In previous studies, a large number of experimental techniques have been used to study BHF; however, the amount of theoretical and numerical simulation work to study BHG is insufficient. In the present study, the concept of BHG profile, i.e., variation of BHG over punch stroke is introduced and it is shown that a properly selected BHG profile can improve the section thickness of formed part and result in the drawing of deeper parts. Here, two methods for the optimization of BHG profile are devised, i.e., the local optimization and the global optimization methods. In the first approach, the best BHG in each punch step is determined and finally, the local optimized BHG profile is achieved. In the second method, however, the empirical model for the prediction of final minimum section thickness in terms of BHG profile is obtained using design of experiments and neural networks. In the next stage, the proposed model is implanted into a simulated annealing optimization procedure to identify a proper BHG profile that can produce the desired blank thickness. Afterward, the BHG profile approach is applied to a variety of initial thicknesses, blank diameters, and materials in order to examine the robustness of method. In this paper, ABAQUS finite element package is used to gather finite element (FE) data and several experiments are performed to verify the FE results.     

板材拉深成形电控永磁压边方法研究

为了克服传统压边方法不能独立施加压边力,电磁压边能耗高且发热量大的问题,提出了一种基于电控永磁技术的压边方法。根据电控永磁技术和拉深成形工艺的特点,研制了带有磁力压边装置的拉深成形模具。采用有限元方法模拟了磁极单元和磁垫的充退磁过程,在进行磁场和力学场耦合分析的基础上,确定了以磁吸力作为压边力施加在成形板坯上的接触压力分布。由有限元软件模拟的电控永磁压边与传统压边作用下板坯的成形效果可知,两种压边方法所得拉深件的应变分布基本一致。采用电控永磁压边方法分别对直径为180 mm和195 mm的08Al板坯（厚度为0.98 mm）进行了拉深实验,拉深高度为48 mm,结果表明,电控永磁压边方法可以实现压边力的独立加载,能够提供足够大的压边力。最后,分别计算了采用传统压边方法、电磁压边方法和电控永磁压边方法的能量消耗,其中,电控永磁压边方法节能效果最好,相对于电磁压边方法,节能高达95%以上。     

Modification of a TEM-goniometer specimen holder to enable beam current measurements in a (S)TEM for use in quantitative X-ray microanalysis

In order to have available a specimen holder suited to measure the beam current as is often required in quantitative electron probe X-ray microanalysis, the rod of a low background beryllium specimen holder of a transmission electron microscope was modified. The tip was electrically insulated from the mass of the microscope and connected electrically to the central contact of a BNC connector mounted on the specimen holder handle. With this modified specimen holder the current absorbed by the specimen and/or the specimen holder could be measured easily and accurately. The modified specimen holder has been used to measure the beam current stability of an analytical electron microscope under various conditions. Data were obtained for tungsten as well as lanthanum hexaboride cathodes. Small changes to other types of specimen tips made it possible to exchange these for the low background tip.     

实时控制变压边力液压系统的改造

介绍了一种实时控制分段变压边力系统改造方案.对原有型号为HHP28-120双动薄板拉深液压机的顶出缸油路进行改造,使整体压边力在拉深过程中能按事先设定的曲线精确变化.结合特殊的双层压边圈结构,实现了分段压边力控制.