金属端子自动送料精密注射模设计

介绍了一种高效率及高精度的金属端子注射模结构,此结构可以使金属端子自动送入模具型腔,注射成型后又能自动脱模,实现模具全自动化生产,提高了模具的生产效率和企业的经济效益。     

线圈架端子组合零件自动化注塑技术

介绍了线圈架端子组合零件自动化生产的成型方案及模具结构。提出将金属端子丝材送入注塑模具切断注塑,线圈架塑料件与金属端子一体成型的生产方案,实现了线圈架端子组合零件的自动化生产,提高了生产效率。     

全自动级进式端子注射模设计技巧

根据五金端子制品的结构特点,对全自动级进式端子注射模设计进行了探索和研究。重点阐述了分型面选择、端子在模具中的定位、模具型腔数量及其布置、制品收缩率、封胶形式、模具与端子相关配合尺寸、浇注系统设计和推杆布置等方面的经验及技巧。对提高全自动级进式端子注射模的设计水平有一定的帮助。     

端子模具的侧刃设计

冲裁侧刃是端子模具中的重要工序,其冲裁形状和凸、凹模结构对端子生产质量影响很大。侧刃设计的正确性与标准化既有利于模具维修的规范化,也为整个模具的顺利生产打下了一个良好的基础。     

制造工艺对LCD端子接触面积的影响

对LCD端子接触面积不足的问题进行了描述,分析了其影响因素主要为:模具精度、端子结构及其变形回弹、装配工艺、电镀层质量等。提出保证模具精度、合理的端子结构和控制其变形回弹、合理的装配力、适当增大镀层厚度等方法来改善LCD端子接触状况并提高其接触面积率,这些方法可供实际生产时参考。     

基于CAE分析的铰链式塑料瓶盖注射模设计

分析了铰链式塑料瓶盖的结构特点,使用Moldflow软件对塑件注射成型过程进行了CAE分析,确定了模具的浇注系统及成型工艺。模具采用点浇口、自动脱螺纹结构,模具结构设计合理,生产效率高。     

滑动垫圈注射模设计

分析了塑件的形状特点和技术要求,设计了一副普通浇注系统3层注射模,并解决了该注射模的自动脱模问题.介绍了模具结构和工作过程,实践证明该模具安全可靠,提高了生产效率.     

点浇口注射模浇注系统自动脱模的设计

通过分析点浇口注射模具浇注系统的结构特点,设计了4种点浇口浇注系统的自动脱模机构,并详细地叙述了浇注系统自动脱模的工作过程,这些机构制造方便,动作可靠,能使点浇口模具全自动生产,提高了生产效率。     

基于CAB分析的铰链式塑料瓶盖注射模设计

分析了铰链式塑料瓶盖的结构特点,使用Moldflow软件对塑件注射成型过程进行了CAE分析．确定了模具的浇注系统及成型工艺。模具采用点浇口、自动脱螺纹结构,模具结构设计合理,生产效率高。     

液压缸盖注射模设计

论述了液压缸盖塑料制品的注射模设计。该模具结构可使塑件自动脱模,大大提高了生产效率。本文给出了详细的设计过程及注射模装配图。     

金属树脂快速模具若干关键技术问题研究

金属树脂模具的型腔质量和机械性能不仅取决于模具材料配方,也取决于快速模具制作工艺,现以微波牛奶杯上盖模具制作为例,实验探讨了包括模具材料配方、脱模剂选择和使用等若干关键技术问题,最后利用所制作的金属树脂模具浇注出了合格塑件。     

铝合金铁型覆砂铸造工艺参数研究

铁型覆砂铸造是在金属型(称为铁型)内腔覆上一薄层型砂而形成铸型的一种新型铸造工艺,其主要工艺参数为铁型壁厚和覆砂层厚度.我们通过不同的覆砂层厚度对铝合金圆柱试样进行铸造,利用热电偶测其凝固冷却曲线,分析了铸造过程中砂型厚度和铁型厚度对冷却速度的影响.     

光盘注射模设计

详细介绍光盘注射模的结构,并重点阐述了其中一些关键结构的设计,通过专用夹具可以装夹金属模片,并以金属模片作为样片大量注射生产出具有相反镜像信息的光盘,生产的光盘符合要求。     

A comparative study of Mg-Gd-Y-Zr alloy cast by metal mould and sand mould

The differences of the microstructure and mechanical property between metal mould and sand mould cast Mg-10Gd-3Y-Zr alloy were investigated both under as-cast condition and after solution heat treatment.In the as-cast specimens,the microstructure is similar and composed of α-Mg solid solution and eutectic compound of α-Mg+ Mg24(Gd,Y) 5;whereas the grain size using metal mould and sand mould is 27 μm and 71 μm,respectively.The eutectic compound of metal mould cast alloy was completely dissolved after solution treated at 500℃ for 8 h,however it needs higher temperature(525 ℃) and longer time(12 h) to achieve the absolute dissolving under sand mould condition.In contrast to metal mould,the peak time of sand mould alloy aged at 225 ℃ and 250 ℃ of was advanced by 4 h and 6 h,respectively.The precipitation reaction sequence in sand mould cast Mg-10Gd-3Y-Zr alloy during isothermal ageing at 250 ℃ follows S.S.S.S.→β″(D019) →β'(cboc) →β1(fcc) →β(fcc) ,which is similar to that in the alloy cast using metal mould.     

An alternative approach in ceramic shell investment casting of AZ91D magnesium alloy: In situ melting technique

In this research, the possibility of ceramic shell investment casting of a magnesium alloy using in situ melting technique was explored. AZ91D granules were charged into shell investment mould and in situ melted under various processing parameters including heating temperature, flux application, shell mould thickness and permeability. Scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction techniques were used to characterise the cast samples. Thermal analysis was employed to further investigate the effect of mould thickness on the solidification behaviour of the metal. It was found that mixing flux with the granules not only reduced the temperature at which melting can be achieved, but it also contributed to produce castings with acceptable surface quality. The use of thinner mould provided higher solidification rate, which is believed to favour in situ melting of the granules. It enabled melting of the granules at 650 °C, which in turn helped to suppress the mould–metal reaction and produce castings with good surface quality. Shell mould permeability showed no influence on suppressing the mould–metal reaction at 650 °C.     

水冷铜型凝固下球墨铸铁凸轮轴研制

介绍了球铁凸轮轴水冷铜金属型铸造工艺,为了满足球铁凸轮轴的要求(QT700-2,铁素体≤5%),适当加入合金元素Cu、Sn,其中Cu控制在1.0%～1.4%,Sn在0.03%～0.05%.球化处理时,减少Mg、RE的加入量,同时对铸件进行正火处理.经批量生产验证,该工艺稳定,效率高,可以满足球铁凸轮轴的生产要求.     

Air gap formation during solidification in cylindrical castings of pure aluminium and eutectic Al-Si

Casting of aluminium and eutectic Al-Si in a cylindrical mould has been performed. The air gap formed between the inner mould wall and the solidified shell was measured throughout the solidification process. Simultaneously the temperature distribution in the metal and the mould was measured. Calculations of the shrinkage of the metal were performed. The shrinkage due to thermal contraction was found to be too small to fit the measurements. A new model for the solidification process and the air gap formation was used, where the effect of the formation and condensation of lattice defects was considered. The condensation of lattice defects was used to explain the shrinkage and the air gap found experimentally.     

Conference Reports

Abstract

The outcome of a long-term programme on the computer-aided design of castings, carried out at Sharif University of Technology, has been the development of computer simulation software known as SUTCAST. This is currently employed in 16 local foundries. The program is based on a numerical method involving a classical approach to an explicit three-dimensional heat-transfer finite difference method. The software has been designed for the solidification simulation of pure metals, and eutectic and long-freezing-range alloys. It has been written for IBM personal computers and compatibles in the Turbo C version 2.01 programming language.

This paper discusses the computer solidification simulation of an Al—12%Si casting poured in a sand mould and the heat- transfer coefficient at the metal—mould interface. A mathematical model for the estimation of the gap width at the metal—mould interface during solidification based on the plane strain thermoelasticity equations is suggested.

The solidification process for Al—12%Si contained with a sand mould was monitored by measuring temperature at different locations within the casting and the sand mould. An experimental procedure was employed to measure the displacement of the metal and mould walls during solidification. The width of the gap was measured as the difference between the location of the casting and the inner surfaces of the mould, which varies with time.

The computer results are compared with the experimental data and are shown to be in good agreement as regards to cooling curves, solidification time and gap size.