The development of an automated process planning and die design system for multi former-bolt products

This paper deals with an automated computer-aided process planning and die design system by which a designer can determine operation sequences even if they have only a little experience in process planning and die design for multi former-bolt products. The approach to the system is based on knowledge-based rules; a process knowledge base consisting of design rules is built. Knowledge for the system is formulated from plasticity theories, empirical results and the empirical knowledge of field experts. Programs for the system have been written in Auto LISP for the AutoCAD using a personal computer. An attempt is made to link programs incorporating a number of expert design rules with the process variables obtained by commercial FEM software, DEFORM and ANSYS, to form a useful package. The system is composed of four main modules. The process planning and the die design modules consider several factors, such as the complexities of perform geometry, punch and die profiles, the specifications of available multi former, and the availability of standard parts. They can provide a flexible process based on either the reduction in the number of forming sequences by combining the possible two processes in sequence, on the reduction of deviation of the distribution and the level of the required forming loads by controlling the forming ratios. As the system using 2D geometry recognition is integrated with the technology of process planning, die design, and CAE analysis, the standardisation of the die parts for multi former-bolt products requiring cold forging process is possible. The system developed will be useful in reducing the trial-and-error os design engineers in determining the diameter and height of the initial cylindrical billet from the final product geometry and the intermediate necessary sequence.     

An Automated Process Planning and Die Design System for Quasi-Axisymmetric Cold Forging Products

This paper deals with an automated computer-aided process planning and die design system with which a designer can determine operation sequences even after only a little experience in process planning and die design of quasi-axisymmetric cold forging products by multistage former working. The approach is based on knowledge-based rules, and a process knowledge base consisting of design rules is built. Knowledge for the system is formulated from plasticity theories, empirical results and empirical knowledge of field experts. Programs for the system have been written in AutoLISP for AutoCAD with a personal computer. An attempt is made to link programs incorporating a number of expert design rules with the process variables obtained by commercial FEM software, DEFORM and ANSYS, to form a useful package. The system is composed of three main modules and five submodules. The process planning and die design module considers several factors, such as the complexities of preform geometry, punch and die profiles, specifications of available multiformers, and the availability of standard parts. The system uses 2D geometry recognition and is integrated with the technology of process planning, die design, and CAE analysis. The standardisation of die parts for wheel bolts requiring a cold forging process is described. The system developed makes it possible to design and manufacture quasi-axisymmetric cold forging products more efficiently.     

Development of an expert system for cold forging of axisymmetric product

This paper deals with an automated computer-aided process planning and die design system by which the designer can determine operation sequences even if they have little experience in process planning and die design for axisymmetric products. An attempt is made to link programs incorporating a number of expert design rules with the process variables obtained by commercial FEM softwares, DEFORM and ANSYS, to form a useful package. The system is composed of four main modules. The process planning and the die design modules consider several factors, such as the complexities of preform geometry, punch and die profiles, specifications of available multi-former, and the availability of standard parts. They can provide a flexible process based on either the reduction in the number of forming sequences by combining the possible two processes in sequence, or the reduction of deviation of the distribution on the level of the required forming loads by controlling the forming ratios. In the die design module optimal design technique and the horizontal split of the die insert were investigated for determining appropriate dimensions of components of the multi-former die set. It is suggested that the proposed method can be beneficial for improving the tool life of the die set in practice.     

An energy consumption prediction approach of die casting machines driven by product parameters

Die casting machines, which are the core equipment of the machinery manufacturing industry, consume great amounts of energy. The energy consumption prediction of die casting machines can support energy consumption quota, process parameter energy-saving optimization, energy-saving design, and energy efficiency evaluation; thus, it is of great significance for Industry 4.0 and green manufacturing. Nevertheless, due to the uncertainty and complexity of the energy consumption in die casting machines, there is still a lack of an approach for energy consumption prediction that can provide support for process parameter optimization and product design taking energy efficiency into consideration. To fill this gap, this paper proposes an energy consumption prediction approach for die casting machines driven by product parameters. Firstly, the system boundary of energy consumption prediction is defined, and subsequently, based on the energy consumption characteristics analysis, a theoretical energy consumption model is established. Consequently, a systematic energy consumption prediction approach for die casting machines, involving product, die, equipment, and process parameters, is proposed. Finally, the feasibility and reliability of the proposed energy consumption prediction approach are verified with the help of three die casting machines and six types of products. The results show that the prediction accuracy of production time and energy consumption reached 91.64% and 85.55%, respectively. Overall, the proposed approach can be used for the energy consumption prediction of different die casting machines with different products.     

Development of an expert system for cold forging of axisymmetric product

This paper deals with an automated computer-aided process planning and die design system by which the designer can determine operation sequences even if they have little experience in process planning and die design for axisymmetric products. An attempt is made to link programs incorporating a number of expert design rules with the process variables obtained by commercial FEM softwares, DEFORM and ANSYS, to form a useful package. The system is composed of four main modules. The process planning and the die design modules consider several factors, such as the complexities of preform geometry, punch and die profiles, specifications of available multi-former, and the availability of standard parts. They can provide a flexible process based on either the reduction in the number of forming sequences by combining the possible two processes in sequence, or the reduction of deviation of the distribution on the level of the required forming loads by controlling the forming ratios. In the die design module optimal design technique and the horizontal split of the die insert were investigated for determining appropriate dimensions of components of the multi-former die set. It is suggested that the proposed method can be beneficial for improving the tool life of the die set in practice.     

A Hybrid Intelligent Systems Approach for Die Design in Sheet Metal Forming

Die design is heavily experience based and the die design process is an iterative procedure of trial and error in order to obtain a final die design for the successful manufacture of stampings. Most automotive industries use internal guidelines and past experience for die design. Even though powerful computer-aided design systems are being used in automotive industry, the lack of adequate analysis tools at the initial die geometry design stage hinders the die manufacturing process, and also necessitates lead times of the order of 5–30 weeks [1]. At the concept design stage, and during the initial die development process, the variations in geometry and process conditions are so large that it is prohibitively expensive to use 3D finite element analysis. The complexity of die design heuristic knowledge hinders the development and application of knowledge-based systems. Hybrid intelligent systems are computer programs in which at least one of the constituent models simulates intelligent behaviour [2]. These models could be knowledge-based systems, artificial neural networks, fuzzy logic systems, etc. In this approach both artificial neural networks, knowledge-based systems and finite-element analysis (FEA) for modelling the design process are used. A simulation-based design approach [3] for the die design process is followed. Artificial neural networks (ANNs) are preliminary design tools which indicate the formability of the component geometry, for the selected process and material conditions. The ANN module is trained from FEA results for a generic set of component geometries, process conditions, and material properties. The final die design validation is carried out by FEA. The intelligent frame-work incorporates rules for material selection, process parameter selection and their modification. Component geometry is a critical parameter which affects the manufacturability of the given part. Hence, an intelligent geometry handling module, which automatically modifies and optimises the geometry of the designed die, is implemented in the present system. Knowledge-based blackboard architecture is used for the integration of various analysis models such as CAD, FEA, and ANN, as an intelligent framework for die design [4]. The hybrid intelligent system provides an integrated decision support environment for simulation and analysis of the forming process, both during the initial die design phase and during the die tryout phase. The hybrid intelligent systems approach supports the capability for automatic evaluation of prospective die design for manufacturability, and performs automatic modification of design inputs. Applications of the hybrid intelligent system for die design are described together with a comparison with shop floor data.     

A system for design of multicavity die casting dies from part product model

Design of a die casting die is a nontrivial task, which depends upon a number of influencing factors related to material, part geometry, manufacturing resources, cost, delivery time, etc. Complexity of this die design activity further increases in case of a multicavity die. Currently available die design systems lack in the level of automation and do not explicitly address multicavity die design. Present work is an attempt to develop a system, which facilitates computer-aided design of a multicavity die casting die. The objective of the proposed system is to automate the process of deciding number of cavities, design of cavity layout and die–base, and core and cavity creation for a multicavity die casting die. The proposed system, which we named Auto_Die_Caster, works as an add-on application to solid modeling software SolidWorks. The proposed system is divided into four modules, namely data initialization, cavity design, cavity layout and die–base design, and core–cavity design. Use of commercial software like SolidWorks as a platform both for part design and generation of die design eliminates loss of data which makes the proposed system quite useful in the industrial scenario. To demonstrate the capabilities of Auto_Die_Caster, it was tried for a number of die casting parts and the results are presented. Proposed system is a step forward to design manufacturing integration for die casting process.     

面向并行设计的模具装配模型描述

通过对传统模具ＣＡＤ系统的分析及目前并行工程等先进制造理论对新型模具ＣＡＤ系统的要求,基于一般模具设计过程及ＥＸＰＲＥＳＳ－Ｇ的研究,提出了面向并行设计的模具装配描述模型,同时讨论了已有装配模型的不足。基于此模具装配模型,解释了实现并行设计的方法与过程     

大型压铸机合模机构的多目标模糊优化设计

基于多目标模糊优化设计的原理,结合大型压铸机合模机构的性能和尺寸要求,建立了符合实际工况的数学模型,并用最优水平截集法求解,用复合形法上机寻优.研究结果表明,多目标模糊优化在合模机构设计方面具有较高的实用价值.     

Development of an automated progressive design system with multiple processes (piercing, bending, and deep drawing) for manufacturing products

This paper describes the research work involved in developing an automated progressive design system with multiple processes such as piercing, bending, and deep drawing for manufacturing products. This approach to make a progressive, flexible working system is based on knowledge-based rules. The knowledge required for this system is formulated from plasticity theories, experimental results, and the empirical knowledge of field experts. The system consists of three main modules: shape treatment, strip layout, and die layout modules. The system is founded on knowledge-based rules and is designed in consideration of several factors, such as the material and thickness of a product, the piercing, bending and deep drawing sequence, and the complexities of blank geometry and punch profiles. The system then generates the strip layout drawing for an automobile product. The die layout module carries out the die design for each process from the results of the strip layout module. The results obtained using the modules enable the designers of manufacturing products with multiple processes to be more efficient in this field.     

A Study on Development of a Die Design System for Diecasting

Diecasting is one of the forming methods for manufacturing a large number of products with short lead time and a good surface by high injection pressure of cast alloy. Die design is composed of selection of cast alloy, design of product, runner and gate design, etc. In reality, however, die design for diecasting has been performed by a trial and error method, which causes economic and time loss. This paper describes the development of the computer-aided design of product and die design. The CAD system has been written in AutoLISP on the AutoCAD with a personal computer. In this study, the die design system for the die casting process has been developed and a flowchart is presented for the automation of die design, especially of the runner–gate system. As the generation process and die design system using 3D geometry handling are integrated with the technology of process planning, die design can be automated. In addition, specific rules and equations for the runner–gate system have been presented to avoid too much trial and error with expensive equipment. It is thus possible for engineers to make automatic and efficient die design for diecasting which will result in a reduction of the required cost and time. An example of a cap-shaped product, i.e. a motor pulley, is given using the proposed flowchart.     

面向压铸模浇道的变参数建模方法研究

针对压铸模浇道建模过程中遇到的几何特征重复生成时的繁琐性、操作过程的复杂性和设计参数的离散性等问题,提出以变参数为主导的浇道建模方法。该方法在浇道特征要求和实用技术基础上,通过对浇道变参数细节特征进行分析,以及浇道特征对金属溶液特性产生不同影响的研究,以UG8.0为研发平台并结合CAD技术,实现了压铸模浇道的参数化、系统化和标准化设计,开发出变参数压铸模浇道设计系统。该系统有效地实现了参数的集中处理,避免了用户的重复操作,缩短了浇道的设计周期,提高了设计精度。     

Axisymmetric extrusion through adaptable dies—Part 3: Minimum pressure streamlined die shapes

In Part 1 of this series of papers, six kinematically admissible velocity fields, as well as the power terms, were developed for use in upper bound models for arbitrarily shaped dies for axisymmetric extrusion. Part 2 compared the results obtained in upper bound models for the six velocity fields through a spherical die shape and demonstrated that the sine-based velocity field was the best. In this final part, the application of the sine-1 field to extrusion through streamlined dies is developed. By fixing the values of two additional constants in the radial flow flexibility function, the two surfaces of velocity discontinuity, which separate the deformation zone from the incoming and outgoing material, will have no shear. In effect, the analysis for streamlined dies can be modeled without the surface of velocity discontinuity power terms. The results for an arbitrarily curved streamlined die, as proposed by Yang and Han, using the sine-1 velocity field and the cylindrical velocity field from the work by Yang and Han are compared. It is found that the upper bound model using the sine-1 velocity field predicts lower values for the extrusion pressure. A method to determine a streamlined die shape is proposed. The method allows flexibility between the entrance and exit by the use of a Legendre polynomial series for representation of the die surface. The method is termed an adaptable die design. The adaptable die design method is used to determine streamlined die shapes, which will minimize the pressure required for the extrusion process.     

基于Web的模具协同设计系统的研究与应用

分析了模具协同设计系统的需求特点,构建了模具协同设计系统的体系结构,并详细定义了模具协同设计系统的功能组成。在此基础上,开发了模具协同设计原型系统,并以多工位级进模协同设计过程为例,对系统进行了验证。     

智能控制在模具温控成形中的应用

模具的温度控制和调节是高效而经济地生产高质量成形零件的必不可少的条件.介绍了智能控制在模具温控成形过程中的应用现状,指出数值模拟对温控成形过程温度场的研究有助于控制成形过程,实现对模具温度的智能控制,使零件的质量得到充分保证.     

基于CBR的模具数字化设计方法研究

以提高模具设计的自动化程度,缩短模具的设计周期,提高模具的设计质量为目的,将CBR技术引入模具的设计,研究了CBR的基本原理以及实例的索引算法.在此基础上采用Visual C++.NET作为开发平台,Oracle作为数据库管理系统,开发了冲裁模具的计算机辅助设计系统,并将该系统应用于具体冲裁模具的设计.应用实例表明方法可行有效.     

基于SOA的业务流程管理在模具协同设计任务管理中的应用

为了实现模具设计任务的自动管理,结合模具设计任务的特点,提出了基于活动树的任务分解模型.该模型能最大程度地避免任务间冲突的发生,并且能够保证模具设计人员之间模型信息的一致.在此模型的基础上,结合业务流程管理技术开发出了一套模具协同设计任务管理原型系统.该系统提高了模具协同设计的自动化程度,实现了模具设计任务的自动管理.     

The runner optimisation design of a die-casting die and the part produced

The accurate prediction of die-casting performance is essential for the design of die-casting dies. The main purpose of die design is to produce an accurate part, but a key role in a good design is also the design of the runner. In order to understand the practical conditions in die casting, this paper studies the runner part and die body parts which have been considered separately during the experiment. A die-casting test has been designed according to experimental methods and the runners have a total of 23 sets of tests.A finite-element method was used to obtain the displacement from the measurement of the temperature in the cavity, and an abductive network has been built for modelling the diecasting process. The abductive network is composed of a number of functional nodes. Once the die-casting parameters (high-speed injected position, runner injected angle, runner sectional ratio) are given, the die-casting performance (the displacement) can be accurately predicted by this network. The optimal die-casting parameters can be searched for by a simulation annealing optimisation algorithm using a performance index to obtain a perfect part.     

压力铸造中模具脱模剂和防粘蜡的选择分析实验

压力铸造中模具脱模剂和防粘蜡种类繁多,如何正确选择对于铸件外观品质和模具寿命有着重要的影响。采用H13试样,在不同的涂敷工艺下,对于脱模剂和防粘蜡的成膜性和涂敷厚度进行实验考察,并且利用扫描电镜观察涂敷防粘蜡后的试样浸入铝液中的时间对其显微组织影响。实验和分析表明,防粘蜡皮膜性能在模具温度为300℃左右时涂敷,并保温2~5m in为最好。     

基于CBR和RST的智能冲模CAD系统研究

冲模设计是一个复杂的过程，严重依赖于设计者的经验，如何提高冲模设计智能化程度一直是冲模CAD领域的研究重点。本文在分析冲模的实际设计过程和智能CAD系统基础上，建立了一个基于IDEF0的；中模CAD系统功能模型，设计实现了一个基于实例推理和粗糙集理论的智能冲模CAD原型系统，并对智能冲模CAD中实例表达、实例检索、实例评价与修改等关键技术进行了研究。使用该系统能提高设计质量和效率，缩短开发周期，降低冲模生产成本。