浅淡电解加工夹具设计

我们在应用电解加工过程中,深之感到夹具的设计和制造,有着重要的作用。如果夹具设计制造不当,不但产品质量无法保证,生产效率低,甚至会使加工无法进行。现谈谈设计电解加工夹具的一点点粗浅体会,并介绍电解导轨槽的夹具。一、电解加工夹具设计电解加工夹具的作用,在于保证工件和阴极间的相对正确位置,并形成封闭的加工区域和液流通道。所以与一般夹具的设计原则不同。我们感到应遵循和注意以下几点: 1.夹具应保证工件与阴极的相对位置准确度,选择恰当的间隙。否则会影响加工质量,     

面向航空发动机薄壁零件加工的自适应夹具设计现状与进展

复杂薄壁工件是航空发动机中的一类关键、重要零件,如何抑制因其弱刚性、材料难加工、强时变特征导致加工过程产生的变形和振动已成为亟待解决的瓶颈问题。夹具的合理布局及提升装夹稳定性可以有效地抑制加工振动。目前,夹具系统的智能化已经成为制约智能加工技术实现的主要瓶颈。研制能够自适应薄壁零件复杂工况的夹具设计成为研究热点。从工件-夹具动力学建模,夹具布局优化、夹紧力优化以及目前自适应夹具设计等几个方面进行综述,希望为今后自适应夹具设计与工程应用提供帮助。     

薄壁零件的电解加工

这里介绍的是在壁厚1.1毫米的附件上电解加工八个槽的问题。零件如图1所示。该零件原用机械加工制造,需先钻定位孔再铣槽。铣槽后大量毛刺留在槽子下部并往内翻,要花费大量时间和劳动力打毛刺。机加单件工时定额为65分钟。现采用电解加工一次成型,不到10分钟即可同时加工好6个零件,效率提高十倍。采用此种方法无需专用电解加工机床,一般的电解设备均能满足要求,只需根据所加工的零件制作一个简单的电解夹具,采用固定式     

成组分度铣夹具应用两则

成组分度铣夹具应用两则南昌飞机制造公司黎自芳１成组铣六方夹具图１所示是六方类零件组的典型零件，以外圆及端面定位加工六方，品种规格繁多。为了减少专用分度铣夹具，缩短生产准备周期，加快新产品研制，在零件分类编组的基础上，将六方零件进行标准化、系统化、通用...     

细长孔加工夹具的定位误差分析

机械加工中,为了保证零件精度的加工要求,必须使零件和刀具及机床相互之间有正确的位置,并使这个位置在加工过程中保持不变.在批量生产中,广泛地使用机床夹具来满足这一要求.一批工件逐个在夹具上定位加工时,由于工件及定位元件实际所占据的位置并不完全一致,导致加工后的零件尺寸不一致,即形成了定位误差[1].定位误差直接影响被加工零件的尺寸与位置精度.夹具定位误差是评价夹具性能的重要指标,定位误差分析是夹具设计中的一个重要环节.全面了解工件位置偏移与定位源误差之间的关系以及掌握定位误差变化规律,有助于提高夹具设计质量和夹具结构的合理性,可获得良好的设计方案.     

超薄扭曲叶片精密电解加工

介绍了由方料经单面电解加工超薄扭曲叶片叶身型面的方法．以及其零件加工难点、夹具和阴极结构及非加工面的保护．用该方法批生产叶片、叶身型面重复制造精度稳定，型面轮廓精度基本满足了无余量修抛要求．     

飞机机械加工零件成组加工的一些做法和体会下

成组工艺装备的设计成组工艺装备的设计主要是指成组夹具的设计。成组夹具和专用夹具所不同的,前者为一组零件服务;而后者仅为一个零件所用。成组夹具为了实现一组零件加工,其结构上具有下列特点:夹具由固定不变和可换调节两部份组成。固定不变部份包括夹具体、传动装置和控制系统等。这部份是通用的,可长期装在机床上,象一个机床附件,它与被加工零件外廓尺寸有关,而与被加工零件几何形状关系不     

车床加工轴类零件径向孔的组合夹具设计

针对镗床加工某轴类零件径向孔系效率低、经济效益差的问题,设计了一套组合夹具,利用这套组合夹具在车床上加工该零件径向孔,解决了这些问题。     

微小薄板类零件的装夹及毛刺转移方法研究

针对微小薄板类零件装夹定位困难、毛刺去除难度大的工艺特点,提出"压板压装坯料+微型夹具固定零件"的微型组合装夹方法,设计三件套微型组合夹具,并提出一种毛刺转移方法,有效解决了微小薄板类零件的装夹及去毛刺难题,提高了微小薄板类零件的加工质量。     

基于UG平台的某型号专用机床夹具CAD系统三维参数化零件建库技术研究与应用

本文在研究通用商品化CAD软件的三维参数化零件建库技术及工装所夹具设计实际归纳总结出的大量具有“企业知识”内涵的常用标准件、组合件及典型实例的基础上，介绍我所与南航联合开发的基于UG平台的某型号专用机床夹具CAD系统三维参数化零件建库技术特点与应用。     

Cathode design investigation based on iterative correction of predicted profile errors in electrochemical machining of compressor blades

Electrochemical machining (ECM) is an effective and economical manufacturing method for machining hard-to-cut metal materials that are often used in the aerospace field. Cathode design is very complicated in ECM and is a core problem influencing machining accuracy, especially for complex profiles such as compressor blades in aero engines. A new cathode design method based on iterative correction of predicted profile errors in blade ECM is proposed in this paper. A math-ematical model is first built according to the ECM shaping law, and a simulation is then carried out using ANSYS software. A dynamic forming process is obtained and machining gap distributions at different stages are analyzed. Additionally, the simulation deviation between the prediction profile and model is improved by the new method through correcting the initial cathode profile. Further-more, validation experiments are conducted using cathodes designed before and after the simulation correction. Machining accuracy for the optimal cathode is improved markedly compared with that for the initial cathode. The experimental results illustrate the suitability of the new method and that it can also be applied to other complex engine components such as diffusers.     

应用Pro/E软件设计时几个问题的探讨

详细介绍了应用Pro／E软件进行设计的过程中在工作目录的设置、小数位置的设置、单位制的设置和转换、系统颜色的改变以及对特征的重定义等方面遇到的问题和解决方法。     

Simulation and experimental investigation on a dynamic lateral flow mode in trepanning electrochemical machining

An appropriate flow mode of electrolyte has a positive effect on process efficiency, surface roughness, and machining accuracy in the electrochemical machining(ECM) process. In this study, a new dynamic lateral flow mode, in which the electrolyte flows from the leading edge to the trailing edge, was proposed in trepanning ECM of a diffuser. Then a numerical model of the channel was set up and simulated by using computational fluid dynamics software. The result showed that the distribution of the flow field was comparatively uniform in the inter-electrode gap. Furthermore, a fixture was designed to realize this new flow mode and then corresponding experiments were carried out. The experimental results illustrated that the feeding rate of the cathode reached 2 mm/min, the best taper angle was about 0.4°, and the best surface roughness was up to Ra= 0.115 lm. It reflects that this flow mode is suitable and effective, and can also be applied to machining other complex structures in trepanning ECM.     

波音公司DCAC／MRM计划

论述了美国波音商用飞机公司如何在实现产品全部数字化基础上,进一步采用90年代新技术）──产品数据管理,在公司内全面展开飞机构形定义和控制及制造资源管理（DCAC／MRM）的庞大计划,说明了此计划的主要内容、工作原理和执行步骤,涉及到单源产品数据仓库、飞机构形定义和控制及精简作业流等。通过这一计划,真正实施并行工程,把市场需求和公司内的生产制造紧密地统一管理起来,极大地提高了企业的整体效益。     

Experimental investigation of rotary sinking electrochemical discharge milling with high-conductivity salt solution and non-pulsed direct current

Electrochemical milling is a modified technique of traditional electrochemical machining (ECM) that can be used to manufacture some helicopter transmission system parts. The use of rotary tools and an inner-jet electrolyte supply pattern can greatly improve the material removal rate (MRR) in a single pass. However, the feed speed is generally limited to minimize the tool wear. To increase the MRR, electrical discharge machining (EDM) is introduced into the electrochemical milling process. The tool rotation is employed to interrupt the discharge and the high-conductivity salt solution and non-pulsed direct current power supply are also adopted to increase ECM, eventually, a new machining method is proposed, which can be called rotary sinking electrochemical discharge milling (RSECD milling). The mechanism of it is explored in this study by analyzing the machined current, MRR, surface morphology, and tool wear at different applied voltages and feed speeds. Besides, the RSECD milling using the tool with a larger diameter is also conducted to further verify the effectiveness. In particular, the MRR can be increased by 742.5% when using the tool with a diameter of 20 mm at the applied voltage of 20 V.     

机载蒸发循环系统结构的轻量化设计

机械结构作为机载蒸发循环系统主要的支撑件,具有较大的质量并承受来自直升机的振动冲击作用,其结构性能影响着整个系统的正常功能,在保证足够强度和刚度的前提下,对结构进行轻量化设计具有重要的理论意义和实用价值。首先,采用ANSYS软件对机载蒸发循环系统进行有限元分析;然后,借助Pro/E与Ansys Workbench之间的双向参数实时传递功能,对结构进行参数化设计,在此基础上采用灵敏度分析法获取对模型优化目标影响较大的关键尺寸参数;最后,采用多目标遗传算法对结构进行优化设计。结果表明:在满足设计要求的前提下,结构质量比原来减少了24.4%,得到了最佳结构参数,实现了轻量化目的。     

C/E复合材料网格缠绕结构三维建模与模具设计

通过对圆柱螺旋线和圆锥螺旋线参数方程的推导,实现了网格结构及模具的三维建模。三维模型的建立,可实现结构空间协调,缩短设计周期,节省研制经费,提高生产效率。在此基础上提出了可行的金属模具设计方案,找到了切实可行的模具加工方法,并在工程中加以应用,取得了较好效果。     

基于知识工程的钣金快速工艺设计系统开发

介绍了国内外现代民用飞机快速研制的实际需求,参考国外航空制造企业的经验和国内飞机钣金专业技术在知识工程方面的研究进展,提出了以知识工程技术为核心,以数值推理为手段,建立钣金快速工艺设计系统的总体思路与技术途径,并通过专家知识库构建和系统软件开发,建立基于知识工程的钣金快速工艺设计系统。通过在民用飞机研制中的应用,批量、自动实现了钣金零件的工艺性分析、工序设计,自动生成工艺分析报告、制造大纲、数控代码,大幅度提高民用飞机研制的工艺设计效率,降低技术人员的劳动强度。     

飞机框式部件柔性装配型架的研究

飞机框式部件柔性装配是实现飞机柔性装配的关键性技术之一,是数字化技术贯穿于飞机装配的全过程。通过对飞机框式部件的工艺及装配型架制造过程的分析,结合飞机数字化制造技术和自动化技术,提出了飞机框式部件柔性装配型架的设计方法。利用孔定位的方式,确定了飞机框上零件的定位分布位置及柔性布局,为飞机框式部件装配提供了柔性化、自动化和敏捷化的制造思路。     

Convex shaping process simulation during counter-rotating electrochemical machining by using the finite element method

In counter-rotating electrochemical machining(CRECM), a revolving cathode tool with hollow windows of various shapes is used to fabricate convex structures on a revolving part. During this process, the anode workpiece and the cathode tool rotate relative to each other at the same rotation speed. In contrast to the conventional schemes of ECM machining with linear motion of a block tool electrode, this scheme of ECM is unique, and has not been adequately studied yet. In this paper, the finite element method(FEM) is used to simulate the anode shaping process during CRECM, and the simulation process which involves a meshing model, a moving boundary,and a simulation algorithm is described. The simulated anode profiles of the convex structure at different processing times show that the CRECM process can be used to fabricate convex structures of various shapes with different heights. Besides, the variation of the inter-electrode gap indicates that this process can also reach a relative equilibrium state like that in conventional ECM. A rectangular convex and a circular convex are successfully fabricated on revolving parts. The experimental results indicate relatively good agreement with the simulation results. The proposed simulation process is valid for convex shaping prediction and feasibility studies as well.