New trends in cold-chamber die casting machine design

Larger and larger proportions of aluminium castings,especially those produced by the die casting process,can be observed during recent years in the automotive industry,house-hold articles and others.In case of the automotive industry,apart from the traditional elements produced by the die pressure method such as engine blocks or crank shaft bedplates,aluminium is displacing steel from structural parts of cars('body in white').The current state and development directions of the structural solutions of cold-chamber die castings are analysed in this paper.These solutions drive the prospective development of these machines and die casting technology.The focus is mainly on essential functional systems such as:hydraulic drives of closing and locking units,as well as pressing in die machines of known companies present on the European market.

Design and Verification of an Auxiliary System for High Vacuum Die Casting

Vacuum die casting is the optimal method to produce high quality aluminum alloy components.At present,there are still very few systematic studies on vacuum die casting theory and equipment design.On the basis of the existing theories of the vacuum die casting pumping and venting systems,a simplified model is established in this research.The model has an aggregate unit consisted of ＂vacuum pump ＋ buffer tank＂ and a cylindrical container（including the shot sleeve,cavity and exhaust channel）.The theoretical analysis is carried out between the cavity pressure and the pumping time under different volume models.An auxiliary system for high vacuum die casting is designed based on the above analysis.This system is composed of a vacuum control machine and a new vacuum stop valve.The machine has a human-computer control mode with ＂programmable logic controller（PLC） ＋ touch screen＂ and a real-time monitoring function of vacuum degree for buffer tank and die cavity.The vacuum stop valve with the ＂compressed gas ＋ piston rod ＋ labyrinth groove＂ structure can realize the function of whole-process vacuum venting.The new system shows great advantages on vacuuming the cavity with a much faster speed by making tests on an existing die casting mold and a 250 t die casting machine.A die cavity pressure less than 10 kPa can be reached within 0.8 s in the experiment and the porosity of castings can be greatly decreased.The systematic studies on vacuum die casting theory and equipment have a great guiding significance for high vacuum die casting,and can also be applied to other high vacuum forming in related theoretical and practical research.

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.

Survey of the 4th China International Diecasting Exhibition

Die casting machines, dies, die castings, peripheral equipments, die lubricants, raw materials for die casting, melting & holding furnaces, cleaning equipments, etc. were exhibited during the 4th China International Die Casting Exhibition, which was surveyed in the paper.

Thin-Wall Aluminum Die-Casting Technology for Development of Notebook Computer Housing

Silicon-based aluminum casting alloys are known to be one of the most widely used alloy systems mainly due to their superior casting characteristics and unique combination of mechanical and physical properties. However,manufacturing of thin-walled aluminum die-casting components,less than 1.0 mm in thickness,is generally known to be very difficult task to achieve aluminum casting alloys with high fluidity.Therefore,in this study,the optimal die-casting conditions for producing 297 mm×210 mm×0.7 mm thin-walled aluminum component was examined experimentally by using 2 different gating systems,tangential and split type,and vent design.Furthermore,computational solidification simulation was also conducted.The results showed that split type gating system was preferable gating design than tangential type gating system at the point of view of soundness of casting and distortion generated after solidification.It was also found that proper vent design was one of the most important factors for producing thin-wall casting components because it was important for the fulfillment of the thin-wall cavity and the minimization of the casting distortion.

基于ProCAST的汽车挂车阀压铸工艺优化

某汽车挂车阀由压力铸造工艺制造生产,铸件的合格率较低。通过对阀体结构进行充分剖析,并利用专业模拟分析软件ProCAST,对其压铸充型过程和凝固过程进行仿真模拟。根据模拟结果,对铸件模具工艺进行优化和生产验证。结果表明,优化后的压铸工艺能够改善产品的缺陷,提高产品的合格率。

Understanding microstructure-property relationships of HPDC Al-Si alloy based on machine learning and crystal plasticity simulation

Al-Si alloys manufactured via high-pressure die casting(HPDC)are suitable for a wide range of applications.However,the heterogeneous microstructure and unpredictable pore distribution of Al-Si high-pressure die castings result in significant variations in the mechanical properties,thus leading to a complicated microstructure-property relationship that is difficult to capture.Hence,a computational framework incorporating machine learning and crystal plasticity method is proposed.This framework aims to provide a systematic and comprehensive understanding of this relationship and enable the rapid prediction of macroscopic mechanical properties based on the microstructure.Firstly,we select eight variables that can effectively characterize the microstructural features and then obtain their statistical information.Subsequently,based on 160 samples obtained via the Latin hypercube sampling method,representative volume elements are constructed,and the crystal plasticity fast Fourier transformation method is executed to obtain the macroscopic mechanical properties.Next,the yield strength,elastic modulus,strength coefficient,and strain-hardening exponent are used to characterize the stress-strain curve,and Gaussian process regression models and microstructural variables are developed.Finally,sensitivity and univariate analyses based on these machine-learning models are performed to obtain insights into the microstructure-property relationships of the HPDC Al-Si alloy.The results show that the Gaussian process regression models exhibit high accuracy(R2 greater than 0.84),thus confirming the viability of the proposed method.The results of sensitivity analysis indicate that the pore size exerts the most significant effect on the mechanical properties.Furthermore,the proposed framework can not only be transferred to other alloys but also be employed for material design.

铝合金一体化压铸技术研究进展

铝合金密度小、比强度高,广泛应用于航空航天和汽车领域的轻量化成形制造。一体化压铸技术生产大型复杂薄壁铸件,能有效帮助飞机、汽车减重增程,是重要的一体化成形技术。全面综述铝合金大型一体化压铸技术的发展,分析免热处理铝合金的成分设计与已开发的铝合金特点,介绍了国内外大型一体化压铸机和压铸模具的研制情况,归纳总结了一体化压铸件充型、凝固、缺陷、微观组织、热应力和疲劳寿命预测的数值模拟研究现状,对一体化压铸技术的发展提出展望。

汽车车身一体化压铸机适用性评价方法及其应用

当前大部分汽车车身一体化压铸机可行性的研究方法较为单一,难以准确地评估其综合性能。为解决以上问题,采用层次分析法赋予权重并利用模糊数学进行综合评价的方式,建立基于AHP的模糊评价方法。构建汽车车身一体化压铸机适用性评价指标体系,建立评语集为较易实现、介于较易实现和可以实现之间、可以实现、介于可以实现和较难实现之间、实现困难。以一种用于新能源汽车车身一体化成型的压铸机为应用案例,邀请52位专业人士投票确定各因素集隶属度,以构建模糊评价矩阵,利用AHP确定的权重计算得出在较易实现的隶属度最大,即在实际生产中综合性能较好。研究表明该型汽车车身一体化压铸机的关键零部件刚度、重复定位精度、能耗、关键零部件的抗磨损对适用性影响较大。

基于改进遗传算法的压铸机钣金车间生产调度优化

针对压铸机钣金车间的生产节拍不同步及机加工设备空闲问题,基于改进遗传算法对压铸机钣金车间生产调度进行优化。构建一个旨在缩短最长完工时间的车间调度模型,采用改进遗传算法进行求解。通过优先级编码规则来优化加工任务的排列顺序,提高编码的直观性和解算效率。通过对压铸机生产企业机架生产情况进行仿真分析,比较生产调度优化前后的完工时间和机加工阶段设备空闲时间,验证所提出的生产调度优化方法的有效性。

基于人工智能的镁合金压铸模标准件快速检索及自动装配系统的研究

人工智能是一门集认知、机器学习、情感识别、人类智能为一体的多学科交叉技术,作者分析了目前镁合金压铸模标准件调用过程中存在的问题,提出了基于人工智能管理的镁合金压铸模标准件快速检索与自动装配系统的开发理念,构建了压铸模快速设计系统。以镁合金仪表盖为压铸模具的设计对象,详细介绍了利用该系统设计镁合金压铸模具的过程。新的基于人工智能的镁合金压铸模标准件快速检索和自动装配系统效率更高,软件操作更简单,可以自我学习。随着设计系统的应用,该系统将变得更加适用,解决了设计师的思维过程无法跟上CAD软件的步伐的问题,对设计高效快速的镁合金压铸模具有参考价值。

一种基于AMESim的压铸机开模定位系统仿真及控制策略研究

本文以压铸机开模定位系统为对象,对一种出口基于开关阀控制的调速系统进行研究,针对系统响应呈现出大惯性特性,且不同位置系统特性存在较大波动,采用常规单段控制会出现定位精度不高的问题,本文对该系统进行了分析并建立了其关键环节的数学模型和AMESim仿真模型,提出了基于多段控制的定位控制策略和出口基于溢流阀控制的液压系统,并在压铸机开模定位系统上进行试验验证,仿真和试验结果均表明,改进的控制策略和液压系统较常规单段控制具有良好的动态特性,对负载扰动表现出更强的适应性和鲁棒性,同时也证明了仿真的有效性,为同类系统的控制器设计提供参考。

大型压铸机试车固定装置的设计

为了保证大型压铸机各项性能指标符合设计要求,在出厂前需要进行试车。对此,设计了大型压铸机试车固定装置。这一装置由螺柱、T形滑块、挡座、圆棒组成,主要用于抵消试车过程中大型压铸机自身产生的水平力的作用。对这一装置的螺柱连接部位及圆棒处进行力学分析,得到受力危险区域。对受力危险区域进行仿真,得到受力临界值。通过设计和分析,保证大型压铸机试车过程的安全性。

液态压铸机变频调速优化设计与应用

为了提升压铸工艺中的设备效能,着重关注了变频调速技术在压铸过程中的优化作用。传统的压铸机采用的异步电动机通常在恒定速度下运作,造成能源浪费。变频调速技术作为一种创新解决方案,能够有效降低能耗并提升整体工作效率。以某企业800 t压铸系统为例,详细阐述了实施变频转换的实际操作流程,以及实施过程中涉及的关键步骤。为对比改造前后性能的变化,对改装后的压铸设备进行了效能特性的专门测试。实验数据表明,变频改造带来了显著的节能效果,同时电动机的运行表现也得到了极大提升。这一成功案例不仅证实了技术改造的安全可行性,还提供了经济效益参考,为同类液态压铸机的变频调速改造提供了参考。

二板压铸机锁模油缸结构探究

传统的三板压铸机是通过合模油缸推动机铰机构,通过机铰机构的放大作用产生锁模力。锁模力的大小受较多因素的影响,很难调节到合适的锁模力。而传统的二板压铸机的锁模力是由安装在二板尾部的4个大锁模油缸直接提供的,导柱从锁模油缸的活塞中孔穿过,单个油缸的直径很大,成本高,装配,维护困难。本文发明的多结构锁模油缸结构的二板机,是把一个大油缸分成了若干个小油缸排布在导柱的周围,装拆维护容易,而且成本低。

负载口独立控制的压铸机比例插装压射速度系统研究

以压铸机压射系统为研究对象,针对只采用出口比例插装阀系统出现启动冲击、低速稳定性差、高速易超调和工作压力高等问题,提出一种独立阀口控制的速度系统,对出、入口比例插装阀同时采用前馈加反馈复合控制。通过采用双比例插装阀对进、出口速度控制的压铸机压射系统进行分析,建立关键元件和压射系统仿真模型,并在现场压铸机上进行试验验证。结果表明,这种控制方式能够消除启动时的瞬间速度前冲,提高了低速段时速度稳定性、降低了高速段超调,并且减小了出口比例插装阀的工作压力,同时也证明了联合仿真的有效性,为同类系统的设计提供参考。

组合成型刀具在基座压铸件加工中的应用

介绍了一款基座压铸件的加工概况,原工艺分别用立铣刀、倒角刀通过程序控制来进行加工,该加工工艺成熟,虽可满足去除余量的目的,加工精度也满足技术要求,但是加工时间长,效率较低。为了减少加工时间,通过观察加工过程,并分析各个部分的尺寸要求,开发了一款加工组合成型刀具,把多种需求的加工流程通过刀具不同部位的形状组合,实现一次性加工就能完成所有部分的切削,从而大大压缩了切削的时间,显著提高了加工效率,降低了生产成本。

压铸机控制箱齿轮齿条式升降机构设计

控制箱体是压铸机的重要操作界面位置所在,操作员通过其执行启动、停止等各项操作。因此,控制箱体的设计不仅需满足功能性要求,还应考虑操作的舒适性;特别是控制箱体的高度调节,对于不同身高的操作员在工作中的舒适性至关重要。提出了一种用于压铸机控制箱体的齿轮齿条式手动升降机构,旨在解决现有控制箱体高度不可调节的问题。该设计通过优化机械结构,实现了便捷性、稳定性与成本的平衡。通过三维建模、仿真模拟及用户使用的综合考量,该机构能够显著提升设备操作的舒适性,展现出广阔的市场应用前景与竞争力。

一体化压铸技术加快了大型压铸机的发展

大型压铸机是实现一体化压铸技术的工作母机,受益于一体化压铸技术在新能源汽车上的运用推广,给大型压铸机(≥锁模力6000t)开发与制造带来了新动能。本文从压铸机的起源开始,对压铸机分类做了说明,讲述了压铸机发展的经历,重点描述了目前我国三家大型压铸机公司开发与制造情况以及所生产大型压铸机的特点。我国大型压铸机制造在近些年得到迅速的发展,与一体化压铸技术在新能源汽车上的运用息息相关,标志着我国大型压铸机制造已跨进了世界的前沿。