基于UGNX/WAVE的注塑模三维虚拟装配设计

文章介绍了基于UGNX／WAVE的注塑模三维虚拟装配方法。通过应用WAVE技术建立了支持概念设计和装配设计的装配模型,实现注塑模从概念设计到详细设计的过程,并通过实例说明这一方法的应用。该方法符合模具设计的规则,可以提高模具设计的质量,缩短设计周期,减少设计费用和新产品投放市场的风险。     

Design for assembly—The key to design for manufacture

The results of the applications of design for assembly techniques to two typical designs are presented. Consideration is given to the total product cost and it is found that major cost reductions can be achieved even when assembly costs are relatively small. It is also found that assembly automation becomes more difficult to justify as a product design is gradually improved.     

岸电电缆输送机结构设计与改进

在深入研究电缆输送机工作原理的基础上,充分考虑现有电缆输送机输送电缆的牵引力和输送效率等方面的问题,对电缆输送机进行了设计及改进,建立了一种港口岸电电缆输送机模型,通过三维造型软件进行虚拟设计,得到最优设计模型。经过性能对比分析,所设计及改进的电缆输送机达到设计要求,为提高电缆输送效率提供了一种有效的解决方案,也为今后关于电缆输送机的研究提供了一定的参考。     

A concurrent engineering based method for developing a baby carriage

An integrated concurrent engineering methodology for developing a baby carriage is proposed. The development process is divided into three stages for considering the design, manufacture, and assembly problems. The product is first designed based on design criteria to ensure the best matching of needs and requirements. Then the parts and machine tools are coded using group technology (GT). The machine groups and the parts to be processed are given in matrix form using the production flow analysis (PFA) method. The machine cells are arranged based on the balance analysis of process time, and a flexible manufacturing system (FMS) is planned. Finally, the assembly line is planned based on the relationship of the parts. Some related parts are collected as a subassembly system. After the subassembly is decided, the work stations are arranged based on the required assembly time to obtain a high-performance assembly line. The results show that not only is the production cost of the product reduced, but also that the competitive properties are improved. This model can also be applied to develop other products.     

An automated assembly environment in feature-based design

In the integration of design and manufacturing, one of the primary techniques is to evaluate the parts in the assembly so that the labour cost can be reduced. In this paper, the mechanical parts within the design and assembly are examined, and an integrated architecture of an assembly model is proposed which includes a proper assembly environment, the interface between the assembly model and feature-based design, and a knowledge-based expert system for assembly analysis. In order to determine satisfactory plans for assembly and to achieve the required functions in the product model, explicit relational information between the major components is implemented. The evaluation of interference checking of the parts and the geometric tolerances (such as perpendicularity, parallelism, and angularity) of the parts in the assembly model are also studied.     

Optimal tolerance design of assembly for minimum quality loss and manufacturing cost using metaheuristic algorithms

Tolerance allocation is a design tool for reducing overall cost of manufacturing while meeting target levels for quality. An important consideration in product design is the assignment of design and manufacturing tolerances to individual component dimensions so that the product can be produced economically and functions properly. The allocation of tolerances among the components of a mechanical assembly can significantly affect the resulting manufacturing costs. In this work, the tolerance allocation problem is formulated as a non-linear integer model by considering both the manufacturing cost of each component by alternate processes and the quality loss of assemblies so as to minimise the manufacturing cost. Metaheuristics techniques such as genetic algorithm and particle swarm optimisation are used to solve the model and obtain the global optimal solution for tolerance design. An example for illustrating the optimisation model and the solution procedure is provided. Results are compared with conventional technique and the performances are analysed.     

基于Solid Works的虚拟装配体设计技术在机械产品设计中的应用

对Solid Works的三维造型、虚拟装配体设计等功能在机械产品开发设计中的应用作了介绍,并在此基础上,以齿轮泵为对象,指出应用Solid Works软件进行机械零部件虚拟装配体设计的基本过程。该方法提高了机械产品开发的效率和设计质量,缩短了产品开发周期,降低了设计费用。     

Accounting for design

Design decides the cost of a product. Ease of manufacture, ease of assembly and a product that customers want bestow competitive advantage on a firm. State-of-the-art accounting systems will reflect resource usage. State-of-the-ark systems will not. Financial benefits can be immense-but many will take time to accrue. Design for service confers benefits on the customer-benefits that may be reflected in the price. Design for disassembly leads to benefits in recycling. Both products and individual parts can be designed for manufacture. Part DFM provides component features in a cost effective way both in choice of materials and in the manufacturing process. Product DFM designs for assembly using the minimum number of parts compatible with product features and overall cost. The author argues that effective accounting techniques are a prerequisite for any real process improvement     

基于CATIA的三维参数化建模方法及其应用

参数化设计是现代CAD软件的核心技术.利用参数化设计手段可使设计人员从大量繁琐的设计、计算、绘图工作中解脱出来,提高了设计效率,可以在实际制造物理样机之前通过虚拟来方便地修改设计,缩短产品开发周期,降低成本,增强市场竞争力.对基于CATIA的三维参数化建模方法及其技术进行了研究,详细地阐述了三维参数化建模的基本方法和一般步骤.并介绍了在CATIA V5中进行铰链四秆机构参数化、可视化和虚拟装配设计的方法,并对该四杆机构进行了干涉分析和运动仿真分析.详细介绍了针对设计要求通过实时修改构件参数实现铰链四杆机构“一模多型”的虚拟装配设计方法.以可视化的形式实现设计意图,提高了设计速度和质量.     

利用GP算法的钢绳芯带式输送机计算机辅助设计系统的研制

简述钢绳芯带式输送机的设计过程,并设计了钢绳芯带式输送机CAD系统的总体结构.该系统以遗传编程算法为核心,解决一组属于面向对象数据库的对象所具有的共性问题.依据模块化设计思想,借助AutoCAD进行参数绘图,开发了钢绳芯带式输送机CAD系统,实现了钢绳芯带式输送机的计算机辅助设计和总图的自动绘制,大幅度地提高了设计效率.     

Optimum tolerance synthesis for complex assembly with alternative process selection using Lagrange multiplier method

Any part cannot be manufactured to the required nominal dimensions due to inherent variations in workmanship, material, and machine. The specification of tolerance on part dimensions plays a major role on performance, quality, and cost of the product. Distribution of tolerance among the components of an assembly is known as tolerance allocation. The selection of alternative processes for tolerance allocation also plays a vital role in reducing manufacturing cost. Near-optimal allocated tolerances are obtained using nontraditional optimization techniques in which the solutions are achieved randomly. Also, there is a chance for omitting the better process for allocation. The results of successive run of the program based on these techniques will not yield consistent results. An attempt has been made in this work to solve the above problem using Lagrange multiplier method for complex assemblies with univariate search method. The methodology has been demonstrated on wheel mounting assembly. The example product after implementing the proposed method would yield 1.4% savings in manufacturing cost as compared with the cost obtained by Singh.     

车身总成组合检具设计方法的研究与应用

基于车身总成件各部件之间的安装关系和各部分的匹配精度,结合实例介绍了一种新型总成组合检具的设计方法。这种总成组合检具能及时发现零件和总成件的设计缺陷,识别和排除存在的问题,同时降低车身制造成本,对车身总成件制造的质量检测和成本控制具有重要的实用价值。     

东风车架装配线生产节拍研究

对东风汽车公司车架厂"天龙"系列车架装配车间生产线现场与生产节拍相关的数据进行了测试、收集和整理.运用工业工程的思想对这些具体的数据进行分析,找出"天龙"系列车架装配生产线上存在的问题和不足,并提出一系列具有可行性的解决方案.从而降低了生产成本,增强了企业的竞争力.     

基于FLUENT的串联盘式管道连续输送机研究

串联盘管道连续输送机是一种新型的输送粉料机械。主要运用FLUENT仿真软件模拟出串联盘管道连续输送机在运输煤粉的一个受力周期内,从动轮旋转不同角度时煤粉在从动轮上分布的体积分数、压力分布以及从动轮和其周围管道、串联盘的受力大小和方向变化。在此基础上,得出串联盘管道连续输送机的从动轮和串联盘在运动过程中受力较小且受力变化平稳,而从动轮上的管道内壁所受合力较大,变化较大,可知串联盘管道连续输送机输送物料量较恒定,整个串联盘式管道连续输送机在运行过程中会产生较大机械振动和噪声。     

Virtual plastic injection molding based on virtual reality technique

Virtual reality (VR), as a new technology, is integrated with software systems for engineering, design, and manufacturing. The integration has given a new impetus to the field of computer-aided engineering. This paper presents a research effort aimed at creating a virtual plastic injection molding (VPIM) environment, which is designed and implemented based on techniques such as VR, multidiscipline simulation, and scientific visualization. The VPIM system includes two parts: designing in VPIM and evaluation in VPIM. It is the first system to scrutinize virtual prototype mock-ups of new products, machines and production processes in interactive graphic simulation. During the evaluating phase, coupled to appropriate computer-based reasoning and decision-support tools and driven by data from the real manufacturing environment, a realistic impression of the process of plastic injection molding and manufacture can be achieved and can be changed interactively, and it is possible to thoroughly examine the planned system and eventually detect and remove any defects and inadequacies. The construction approach and key techniques (FEA, virtual assembly, stereoscopic display, a triangulated boundary-representation of an approximating polyhedron, collision detection, etc.) of the system are described in detail. The overall system is a powerful new approach for highly relevant industrial application of VPIM which focuses on the construction and assessment of alternate manufacturing sequences and mold design in an early design stage. Improvement of the design and manufacturing process will lead to better design and reduced development time and cost.     

车身装配虚拟样机建模研究

传统的车身装配设计需要多轮实物试制,增加了周期和费用,为此提出了支持虚拟样机技术的车身装配集成建模框架。该集成框架分为基于焊装特征的装配建模、偏差传递计算模型和装配环境仿真模型等三个子模型,并以产品数据管理为平台,通过接口方式实现了各子模型中装配数据和过程信息的协调管理。最后给出了一个某实际车身前地板装配设计的实例。初步实践认为,该集成框架可对缩短装配开发周期、降低车身试制费用提供有效支持。     

Integrated intelligent design and assembly planning: A survey

This paper reviews the relevant literature of the development of methodologies and systems for integrated intelligent design of assembled products and processes. Based on a combination of the concurrent engineering approach and artificial intelligence techniques, an assembly oriented intelligent scheme for the integration of design and planning is proposed, in which the following components or activities are considered and carried out concurrently and intelligently: assembly modelling and design (conceptual design; preliminary design; detailed design), assembly process planning, assembly system layout and design, assembly simulation, econo-technical (e.g. assembl-ability, assembly time and cost) and ergonomic analysis and evaluation. The literature is reviewed and discussed in relation to the methodologies and systems of implementing the above components or activities and an integrated environment to support them. In addition, some research of our group on this topic is introduced.     

2-m望远镜装配体的模态优化及随机振动响应

以2-m望远镜的装配体为研究对象,综合利用模态分析和优化设计的方法,将望远镜装配体的结构参数作为设计变量,并以装配体总重量保持不变为约束条件,以正交试验和BP神经网络的方法建立起装配体的一阶共振频率为目标函数,通过遗传优化计算,得到了一组合理的结构参数搭配,使得其一阶共振频率提高了10.27%,更不易发生共振。为对比优化前后望远镜装配体结构的性能,通过随机振动响应分析,证明了优化后的结构动态刚度增大,振动响应相应减小了。     

基于宽容分层序列法的飞机装配公差稳健设计技术

飞机制造中由于工序能力指数和公差等设计变量存在变差,可能导致无法满足飞机装配质量要求以及制造成本波动较大的问题。运用稳健设计方法建立了飞机装配公差的可行稳健性和敏感稳健性两类设计模型。可行稳健设计考虑了公差等设计变量对装配可行性的影响,使其变差不影响装配功能的实现;敏感稳健性设计则考虑了公差等设计变量对制造成本和装配质量的影响,在目标成本较小的前提下使得目标成本和装配质量受设计变量变差的影响最小。提出了针对飞机装配公差可行敏感稳健设计的多目标优化问题的宽容分层序列求解算法。将公差设计中制造成本、装配质量波动、制造成本波动多个设计目标按照重要性依次排序。首先求解成本最小情况下的公差一般优化解,然后在成本最小值的宽容约束下,求得具有装配质量波动最小值的公差,最后在上述两个优化目标的宽容约束下,求得成本波动最小的最优公差。应用实例和分析结果表明了方法的有效性。       

Robust Tolerance Design by Response Surface Methodology

The Response Surface Methodology (RSM) approach is adopted for data analysis for an experimental model in order to determine the optimal component tolerances in an assembly. The response variable is the total cost, which consists of quality loss and tolerance cost. RSM is a combination of mathematical and statistical techniques, which provides designers, not only with the optimal tolerance values, but also with the critical components in an assembly. This feature is very important during the design activities since it enables designers to have feedback and suggestions for possible design improvement. Using RSM to optimise and analyse the experimental results, a tolerance design for quality improvement and cost reduction can be achieved at an early stage of design, particularly, in an uncertain design environment.