Reducing the effects of weldlines on appearance of plastic products by Taguchi experimental method

Weldlines influence not only strength of injection products but also the appearance of the products. This paper studies the effects of processing parameters on the appearance of weldlines by Taguchi experimental design method. Weldlines are obtained by the right door of copy machine which is modeled with three gates. The pictures of molding products are taken by digital camera. The samples of products and weldlines are extracted by software photoshop. The hue values of the samples of products and weldlines are calculated by software matlab. The visibility of weldlines is defined with the difference of the hue values of products and weldlines. By analysis, it turns out melt temperature, injection velocity, and injection pressure are the main factors which influence the appearance of weldlines.     

工程稳健优化设计

本文从工程设计观点讨论了设计解的稳健性、稳健设计和稳健优化设计的基本概念,提出了一种基于随机优化技术的稳健优化设计的建模原理和求解算法,这一方法将通过调整设计变量的名义值和控制它的容差来考虑可控变量和不可控参数的变差对产品质量的影响,以提高设计解的可行稳健性和质量函数的不灵敏性。     

A CAD/CAE-integrated injection mold design system for plastic products

Mold design is a knowledge-intensive process. This paper describes a knowledge-based oriented, parametric, modular and feature-based integrated computer-aided design/computer-aided engineering (CAD/CAE) system for mold design. Development of CAx systems for numerical simulation of plastic injection molding and mold design has opened new possibilities of product analysis during the mold design. The proposed system integrates Pro/ENGINEER system with the specially developed module for the calculation of injection molding parameters, mold design, and selection of mold elements. The system interface uses parametric and CAD/CAE feature-based database to streamline the process of design, editing, and reviewing. Also presented are general structure and part of output results from the proposed CAD/CAE-integrated injection mold design system.     

转轴的抗疲劳稳健优化设计研究

结合转轴的失效模式,建立了转轴的抗疲劳稳健优化设计模型,利用Visual C＋＋、SQL开发完成其原型系统。整个设计过程充分考虑了不确定因素对疲劳强度的影响,以提高转轴质量的抗干扰能力,保证了质量的稳健性。     

A systematic computer-aided approach to cooling system optimal design in plastic injection molding

Cooling system design is of great importance for plastic injection molding because it significantly affects the productivity and quality of the final products. In this paper, a systematic computer-aided approach is developed to achieve the cooling system optimal design. This approach expiates the trial and error process normally practiced in conventional cooling system design based on the designer's experience and intuition. Various aspects of the optimization process for cooling system design are investigated including cooling analysis using boundary element method (BEM), a perturbation-based approach to design sensitivity analysis, optimization problem formulation, and a novel hybrid optimizer based on Davidon–Fletcher–Powell (DFP) method and simulated annealing (SA). A case study shows that the proposed methodology for cooling system optimal design is efficient, robust and practical.     

齿轮传动稳健优化设计系统的实现

在研究稳健优化设计理论的基础上,构建稳健优化设计系统模型,并应用于齿轮传动设计中.利用Visual C 、SQL和UG开发完成其原型系统,该系统主要由产品总体性能的稳健性分析模块、传动稳健优化设计模块、轴系的稳健优化设计模块以及基于UG的齿轮和轴系建模模块等组成,实现了齿轮传动的稳健优化设计,提高了传动机械抵抗外界因素干扰的能力,保证了质量的稳健性.     

纯滞后对象的鲁棒状态优化设计方法

纯滞后对象是一种很难控制的对象。针对纯滞后对象,提出一种串级双环状态反馈控制方式,使这种对象获得较理想的控制品质。系统的设计方法包括：采用数值逼近方法将对象拟合成有理多项式,并选择一种近乎理想的最优低通滤波器作为串级系统内外环的参考模型,并引入状态观测器,大幅度地减少状态的检测数量;采用内外环系统的协调设计,拉开内外环回路的操作频率;同时引入伺服补偿器,大大提高系统的鲁棒性。通过具体的工业对象进行仿真实验,证实该方法相当有效。     

稳健优化设计的研究现状及发展趋势

稳健设计是提高产品质量的有效方法。介绍了稳健优化设计的基本概念和方法。综述了它的研究现状，分析了各种稳健设计方法的特点，指出了稳健优化设计的发展趋势。     

汽车零部件稳健优化设计的实现策略

从工程设计的观点，应用稳健优化设计的方法来考虑可控制参数和不可控制参数的变异对产品质量的影响，以提高设计解的可行稳健性和质量函数的不灵敏性。重点讨论随机问题的稳健优化设计模型和基于灵敏度分析的稳健优化设计模型，并运用基于灵敏度分析的稳健优化设计方法对汽车离合器膜片弹簧进行设计计算。     

50型无螺纹塑料三通的注塑模具设计

介绍了CAD环境下塑料三通模具设计的过程。运用三维设计软件UG建立塑件的三维模型,分析了塑料三通塑件的工艺特点,并针对其特点设计了一模两腔注射模。同时分析了该模具的工作原理。该模具结构设计巧妙,工作可靠,操作方便,生产效率高,塑件达到技术要求。     

浅析注射成型塑料件结构设计

从注射成型塑料件结构设计的角度出发,结合材料本身特性及注塑生产的工艺特点,总结了注射成型塑料件结构设计上的一些要点和注意事项,列举了若干设计中经常采取的结构形式和改进方法,为注射成型塑料件的结构设计给出了参考。     

注塑产品工艺参数的计算机管理

介绍了一个注塑工艺参数管理软件的实际开发过程.随着工艺参数记录的增加,可将此作为以后开发注塑工艺参数专家系统的知识库,实现注塑工艺参数的智能给定.     

汽车仪表盘注塑模优化设计

本文分析了某轿车仪表盘结构工艺性,采用潜伏式浇口,设计了仪表盘的浇注系统.同时介绍了该产品的注塑模具结构和设计、制造要点.通过优化模具设计,采用改进的模仁加工方法,不但提高模具质量、缩短模具开发周期、同时还极大的降低了模具的成本,提高企业的市场竞争力.对于其它类似的零件也有极大的借鉴作用.     

基于MSRE的机械产品质量特性稳健优化设计方法

为了解决产品质量特性优化设计过程中设计参数发生变差时,最优解变为违反约束条件的不可行解的问题,对产品质量特性的稳健性和稳健性度量进行了分析,建立了基于最小灵敏域估计的产品质量特性稳健优化数学模型,提出了多目标产品质量特性稳健优化设计流程。根据该模型,采用广义差分多目标进化算法求得多目标质量特性稳健优化问题的Pareto稳健优化解集,并使用基于模糊集合理论的方法选择出最优解。在满足产品质量特性设计要求的前提下,优化产品质量特性,提高产品质量特性性能对设计参数变差的稳健性。最后,应用该方法对高速工业平缝机挑线机构进行质量特性稳健优化设计,证明了该方法在工程应用中的正确性与高效性。     

Automatic feature recognition for plastic injection moulded part design

The design of plastic injection moulded part is a highly iterative process and depends largely on the human expertise including product designers, mould designers, manufacturing engineers, who need to possess thorough and broad specific knowledge and experience. The automatic recognition of features for injection moulded parts is the first prominent stage for any automatic design evaluation system. In this paper, features of plastic product are classified in three hierarchical levels of primitive features, complex features and high-level complex features. The proposed method adopts a hybrid approach, which combines the graph theoretic approach with the logic approach. Methodologies of enhanced multi-attributed adjacency graph (EMAAG) and feature-interaction feature graph (FIFG) for automatic extraction of primitive features and complex features of plastic parts, respectively, are presented. The test example shows that the methodologies developed can recognise various features of injection moulded parts successfully.     

注塑件协同设计的实践

以某公司的数码相机开发为实例,详细研究采用协同设计模式开发产品的结构、流程及关键技术。     

注射压制成型塑机的设计原理

注射压制成型是一种生产塑料制品的新工艺。这里介绍一种用于此法生产的特种塑机的工作原理,并对其关键部件———合模机构的结构特点、受力情况、油缸推力的计算作了详尽的分析,给出了设计公式。     

机电产品绿色优化设计方法

基于机电产品设计资料,引入产品结构树型图、产品材料构成分析、产品可拆解性和能源回收指数等概念,评估了机电产品的可拆解性和能源回收性;构建了合并材料和整合产品功能单元两种绿色优化设计方法.以四川绵阳某企业B型超声仪器为例,通过优化设计前后产品零/部件数量、拆解步数、拆解时间和能源回收指数的对比,验证了该方法的有效性.     

Automatic datum dimensioning for plastic injection mould design and manufacturing

Datum dimensioning (or ordinate dimensioning) technique is very popular in plastic injection mould drawings where the location dimensions of a large number of hole features must be specified in the drawings of the mould plates. Although commercial CAD/CAM systems provide semi-automatic tools to assist the designer in the dimensioning process, it is still a very tedious process, as the user has to specify the location of each dimension tag. This paper reports a completely automatic method where optimal placements of the dimension tags can be determined. The method employs dynamic programming technique to optimize the dimension process with respect to several criteria that can be selected by the user. The method has been implemented and incorporated into a commercial CAD/CAM system, and examples are given to illustrate the important features of the program.     

Prediction of warpage in plastic injection molding based on design of experiments

In terms of injection processing parameters, a mathematical model for prediction of warpage was formulated based on design of experiments (DOE). First, the five most influential parameters were screened by using fractional factorial design (FFD): melt temperature, coolant temperature, injection time, V/P switch over and mold temperature. Second, considering the other four principal processing parameters except the melt temperature, the predicting mathematical model was founded by using central composite design (CCD) of experiments and FE simulation. Finally, the results of statistical analysis were collected from software Moldflow. The results suggested that the mathematical model can be used to predict warpage with adequate accuracy. Hence, it indicated that corrective and iterative design steps can be initiated and implemented for better quality of products without resorting to physical trials in plastics injection mold by using this predicting mathematical model.