Intelligent control of gas-assisted injection molding control systems

This study described the design and construction of gas-assisted injection molding systems incorporating a traditional injection molding machine. This combined system is called a gas-assisted injection molding control system (GAIMCS). The mathematical model of GAIMCS with nonlinear dynamics is difficult to establish accurately. Therefore, model-free intelligent control strategies were developed to control this system and evaluate its control performances. This work presents two intelligent control strategies: (1) traditional fuzzy controller (TFC), and (2) grey prediction fuzzy controller (GPFC). The GAIMCS was controlled by the GPFC, which was compared to a TFC to evaluate the system control performance. The GPFC achieves better control performances in accelerating rise time, and it reduces the system steady-state error better than the TFC for high-pressure gas control in GAIMCS, based on the verified experimental results.     

基于遗传算法的注塑机肘杆机构优化设计

遗传算法对于多参数系统优化设计具有较好的鲁棒性。针对注塑机肘杆机构优化设计的问题,通过对注塑机单肘杆合模装置的运动分析,建立了数学模型。以肘杆机构长度最小为目标,利用遗传算法进行了优化设计,并与常规设计方法进行了比较。研究结果表明,基于遗传算法的优化设计体现出了明显的优化效果,具有一定的实际应用价值。     

Structural scheme optimization design for the stationary platen of a precision plastic injection molding machine

The current development of precision plastic injection molding machines mainly focuses on how to save material and improve precision, but the two aims contradict each other. For a clamp unit, clamping precision improving depends on the design quality of the stationary platen. Compared with the parametric design of stationary platen, structural scheme design could obtain the optimization model with double objectives and multi-constraints. In this paper, a SE-160 precision plastic injection molding machine with 1600 kN clamping force is selected as the subject in the case study. During the motion of mold closing and opening, the stationary platen of SE-160 is subjected to a cyclic loading, which would cause the fatigue rupture of the tie bars in periodically long term operations. In order to reduce the deflection of the stationary platen, the FEA method is introduced to optimize the structure of the stationary platen. Firstly, an optimal topology model is established by variable density method. Then, structural topology optimizations of the stationary platen are done with the removable material from 50%, 60% to 70%. Secondly, the other two recommended optimization schemes are given and compared with the original structure. The result of performances comparison shows that the scheme II of the platen is the best one. By choosing the best alternative, the volume and the local maximal stress of the platen could be decreased, corresponding to cost-saving material and better mechanical properties. This paper proposes a structural optimization design scheme, which can save the material as well as improve the clamping precision of the precision plastic injection molding machine.     

Multiobjective optimization of injection molding parameters based on soft computing and variable complexity method

The objective of this study is to propose an intelligent methodology for efficiently optimizing the injection molding parameters when multiple constraints and multiple objectives are involved. Multiple objective functions reflecting the product quality, manufacturing cost and molding efficiency were constructed for the optimization model of injection molding parameters while multiple constraint functions reflecting the requirements of clients and the restrictions in the capacity of injection molding machines were established as well. A novel methodology integrating variable complexity methods (VCMs), constrained non-dominated sorted genetic algorithm (CNSGA), back propagation neural networks (BPNNs) and Moldflow analyses was put forward to locate the Pareto optimal solutions to the constrained multiobjective optimization problem. The VCMs enabled both the knowledge-based simplification of the optimization model and the variable-precision flow analyses of different injection molding parameter schemes. The Moldflow analyses were applied to collect the precise sample data for developing BPNNs and to fine-tune the Pareto-optimal solutions after the CNSGA-based optimization while the approximate BPNNs were utilized to efficiently compute the fitness of every individual during the evolution of CNSGA. The case study of optimizing the mold and process parameters for manufacturing mice with a compound-cavity mold demonstrated the feasibility and intelligence of proposed methodology.     

滑雪板底板注射模设计

介绍在卧式注射机上生产滑雪板底板,底板中间层的不锈钢片采用嵌件方式进行生产,一方面保证了产品的质量,另一方面减少了装配,保证了产品的外观。金属嵌件注射模的生产一般在立式注射机上进行,较少使用卧式注射机,如何设计在卧式注射机上生产的金属嵌件注射模,要考虑的问题很多,就不锈钢嵌件在模具中的定位问题、注射成型工艺、顶出结构系统等注射生产中涉及到的内容进行论述交流。     

Multi-objective optimization of MIMO plastic injection molding process conditions based on particle swarm optimization

Determining optimal process parameter settings critically influences productivity, quality, and cost of production in the plastic injection molding industry. Selecting the proper process conditions for the injection molding process is treated as a multi-objective optimization problem, where different objectives, such as minimizing product weight, volumetric shrinkage, or flash present trade-off behaviors. As such, various optima may exist in the objective space. This paper presents the development of an experiment-based optimization system for the process parameter optimization of multiple-input multiple-output plastic injection molding process. The development integrates Taguchi’s parameter design method, neural networks based on PSO (PSONN model), multi-objective particle swarm optimization algorithm, engineering optimization concepts, and automatically search for the Pareto-optimal solutions for different objectives. According to the illustrative applications, the research results indicate that the proposed approach can effectively help engineers identify optimal process conditions and achieve competitive advantages of product quality and costs.     

塑料注射模具的并行设计方法

塑料制品注射成型属于一次成型工艺 ,传统的串行模具设计和制造方式 ,造成了对设计经验的过分依赖和模具返修率的提高 ,本文举例介绍了基于流动模拟技术的注射模并行设计方法 ,说明了 CAE对模具结构设计和相关注塑工艺的指导作用。     

注塑机液压系统绿色设计的策略与展望

注塑机液压系统的绿色设计包括节能、降噪、防漏和防污染等方面,每一个方面有特定的技术手段来实现。详细地介绍了注塑机液压系统的绿色设计及其优缺点,并提出应根据注射成形制品的工艺、关键设备的研发水平采取相适应的节能技术,以提高整机的性价比的建议。     

基于SIMATICS7-200的注塑机控制系统设计

采用继电器和开关阀的注塑机控制系统的接线复杂、控制精度低、维修不便且缺乏柔性,基于PLC技术的控制方式可大大提高整机的综合性能。本文选用SIMATICS7-200小型PLC系统对注塑机的控制单元进行了通用化设计：包括系统的硬件接线和I/O分配;采用STEP7-Micro/WIN32软件平台进行编程,方式灵活、界面友好且调试方便。     

基于单片机的注塑机温控系统设计

塑料注塑成型机的诸多输入、输出参数中,料筒温度是工作过程中的重要被控参数。论文针对传统注塑机温控系统存在的超调量大、调节时间长等诸多不足,提出了以单片机为控制核心,应用模糊控制理论,设计出模糊控制器,实现注塑机温度的实时控制,对于提高注塑机温度控制精度具有较好的意义。     

注塑机模板应力的有限元分析及电测实验分析

模板是注塑机合模机构的重要零件.通过对移动模板应力进行有限元分析,并用电测法对模板应力进行测试,验证了有限元计算模型的正确性及边界条件的合理性.计算和测试结果对注塑机模板的优化设计具有重要的工程参考价值.     

基于BP-NSGA的注塑参数多目标智能优化设计

为获得成型性能最优的注塑参数设计方案,提出了基于BP神经网络和非支配排序遗传算法的注塑参数多目标优化方法。将注塑模结构尺寸参数和注塑工艺参数作为待优化的设计变量,建立了以高质量、低成本、高效率为优化目标的注塑参数优化设计模型。基于非支配排序遗传算法获取给定参数范围内的所有Pareto最优解,并通过建立多输入和多输出的BP神经网络来快速获得非支配排序遗传算法优化进程中所有个体的适应度值。开发了基于BP神经网络与非支配排序遗传算法集成的注塑参数智能优化设计系统,并通过鼠标注塑参数设计实例,验证了其适用性和有效性。     

Trade-off analysis in multi-objective optimization using Chebyshev orthogonal polynomials

In this paper, it is intended to introduce a method to solve multi-objective optimization problems and to evaluate its performance. In order to verify the performance of this method it is applied for a vertical roller mill for Portland cement. A design process is defined with the compromise decision support problem concept and a design process consists of two steps : the design of experiments and mathematical programming. In this process, a designer decides an object that the objective function is going to pursuit and a non-linear optimization is performed composing objective constraints with practical constraints. In this method, response surfaces are used to model objectives (stress, deflection and weight) and the optimization is performed for each of the objectives while handling the remaining ones as constraints. The response surfaces are constructed using orthogonal polynomials, and orthogonal array as design of experiment, with analysis of variance for variable selection. In addition, it establishes the relative influence of the design variables in the objectives variability. The constrained optimization problems are solved using sequential quadratic programming. From the results, it is found that the method in this paper is a very effective and powerful for the multi-objective optimization of various practical design problems. It provides, moreover, a reference of design to judge the amount of excess or shortage from the final object.     

基于机器学习和多目标算法的钛合金插铣优化

针对钛合金的插铣加工过程开展试验和优化研究。以材料去除率和切削力为目标，采用机器学习和多目标优化算法相结合的方法来优化插铣切削参数；以主轴转速、径向切削宽度、切削步距和每齿进给量为试验变量，采用田口方法对试验变量组进行缩减。将机器学习方法与传统一阶和二阶回归方法比较，发现机器学习有很好的预测精度且解集分布更合理。分别采用MOEA/D、NSGA-Ⅱ、SPEA2、NSPSO算法对问题进行求解，并比较它们的性能，结果表明NSGA-Ⅱ综合表现最佳。最后将优化结果与初始参照进行比较，发现优化结果可以显著提高材料去除率并减小切削力，达到了高效稳定加工的目的。     

液压驱动双曲肘斜排列七支点合模机构的分析研究

双曲肘斜排列七支点合模机构是一种创新的注射机合模机构,液压驱动系统根据肘杆机构的特性进行设计,两者之间相辅相成使机构的性能进一步提高。研究了机构的运动学、力学的性能,分析了机构运行性能与液压驱动性能之间的关系,提出了机构的机械和液压的主要技术参数的理论计算和设计准则,并通过实例验证了设计理论计算和公式的可行性,为机构的开发和应用提供了理论基础和工程设计方法。实例研究表明,双曲肘斜排列七支点合模机构同比双曲肘斜排列五支点合模机构,行程比大于一倍,液压驱动节能35%,系统液压驱动装载功率下降40%。     

用注射分析对悬浮填料结构优化

悬浮填料的结构对其挂膜性能影响较大,设计时需要重点考虑其结构优化.在现有悬浮填料结构的基础上进行改进,设计三种新型填料结构,采用注射分析软件对这些悬浮填料的注塑性能进行模拟计算,了解塑胶熔体在填料模腔中的流动状况,得到这些填料结构上各点的注塑时间、塑胶压力、温度和塑胶流动状况等数据,并根据这些数据比较它们之间的注塑优劣,数据显示,加筋多面空心球结构注射性能比较好.     

基于ANSYS的注塑机结构分析及动模板优化设计

以某型号注塑机为研究对象,在Pro/E和ANSYS协同设计分析环境下,对注塑机锁模机构进行整体建模及分析。分析结果显示动模板在150kN的锁模压力下变形和应力变化较大。根据有限元分析结果,利用ANSYS优化模板对动模板结构进行优化设计,优化后的动模板的应力以及变形显著降低,对产品性能的改进起到了良好的指导作用。     

注塑件特征建模及塑件智能尺寸换算

探采用基于特性和知识相结合的技术，建立注塑件产品模型，实现注塑件尺寸到成形零部件尺寸的智能转换，为建立注塑模型腔型芯模型打下基础，并以ＵＧＩＩＶ９．０为支撑软件，用其Ｍａｃｒｏ及二次开发语言Ｇｒｉｐ实现。     

电控双泵液压源在注塑机上的节能研究

针对传统注塑机溢流损失严重、电力消耗大等问题,提出了一种通过控制异步伺服电机转矩和转速,以实现对注塑机输出压力和流量进行控制的方案。在该电机控制的液压动力源中,采用了串联双齿轮泵的方案,以满足大型注塑机瞬时大流量输出的要求。通过压力与流量反馈形成闭环控制,提高了输出压力与流量的控制精度,并大大提升了注塑机液压系统的节能效果。设计了利用电控双泵液压系统对传统注塑机液压系统改造的方案,并通过实验验证了异步电机伺服泵控系统在注塑机上的节能效果。     

注塑机合模机构及模板的优化设计

简述了我国注塑机合模机构优化设计的研究与应用，并结合本人研究课题论述了基于有限元分析的注塑机模板的优化设计。