布勒两板压铸机合模系统介绍

两板压铸机和三板压铸机的区别主要在于合模系统。两板压铸机的合模系统去除了三板压铸机中的后座板,只含有动模板和定模板。同时,在4根大杠尾端增加了随动锁紧机构取代了曲肘机构。两板合模系统主要由动模板、定模板、大杠、随动锁紧机构及合模缸组成。4根大杠仍然作为动、定模的连接及锁紧构件,但长度缩短,并在尾端增加了夹持齿槽。随动锁紧机构中包括对开螺母和锁紧油缸。对开螺母能够打开和闭合,闭合时与大杠上的夹持齿槽啮合,打开时解除啮合。锁紧缸是一个薄型液压室,用于拉伸大杠锁紧模具。开合模缸位于动模板后端,完成开合模动作。     

通用模外定距锁紧机构

<正> 在塑料注射模中,为了确保塑件留在动模,有时需要定距分型锁紧装置,常用的定距锁紧方式有模内定距锁紧和模外定距锁紧机构。但每副模具的锁紧机构都应按模具的大小进行设计,增加模具设计工作量。现介绍一种通用的模外定距锁紧机构。     

压铸注塑设备合模机构的分析及改进

通过对压铸机、注塑机合模装置锁紧机构的分析,提出一种新型的两板机合模机构。与目前市场上常见的合模机构不同,其区别在于锁紧机构,采用随动螺母和锁紧油缸进行锁紧,锁模力即为螺栓预紧力,并可实时控制随动螺母与动模板间隙使其保持在一个固定值,随动螺母采用标准水系统45°锯齿形螺纹。校核了螺纹连接强度,并基于ANSYS进行了应力分析。     

悬臂式冲模自动锁放装置的实践

<正> 我厂生产图1所示圆筒形零件,在圆筒形壁上有一曲线槽。该曲线槽以前采用手动锁紧悬臂冲压,由于手工操作用力不均,造成凹模易损坏,而且劳动强度大。     

弯曲模滑块卸料机构设计

为了实现弯曲模的自动卸料 ,设计了滑块卸料机构 ,介绍了该机构的工作过程及其设计要点。采用自动卸料机构 ,降低了劳动强度、提高了生产效率、保证了操作安全     

摩擦压力机方圆通用模座的设计

我厂过去摩擦压力机用的模座种类繁多,结构笨重,需经常更换模座,因此劳动强度大,同时为加工制造模座要花费大量时间。为了克服上述缺点,我们在长期生产实践的基础上,设计出一套方、圆通用模座,其结构如     

快速修复模锻锤模座的方法

模座是模锻锤上的重要零件之一。模座的质量好坏,直接影响着锻件质量。模座属于易损件,常在燕尾槽底面及两侧面出现打塌、凹坑等破坏现象,严重影响着锻件质量。过去,我们采用拆下模座,送到热处理车间进行预热,然后用电焊条堆焊,再送到机修车间进行冷加工的修复工艺。这种工艺修复周期长(需7天时间),成本高,拆除模座困难且劳动强度大,故现在我们采用了在模锻锤上直接对模座进行堆焊、打磨的修复工艺,大大缩短了修复时间(需2天),修复成本大为降低,且     

温控盒注射模设计

介绍了温控盒塑料件注射模的结构及脱模方法。该注射模最显著的特征是侧滑块型芯设计在定模一侧且锁紧机构设计在模具结构内部，注射模整体结构紧凑。     

快速换模技术在锻造自动化生产线上的应用

利用叉车配合吊装等传统的模具更换模式通常需要花费大量时间去找准模座和设备的定位，换模效率较低。针对某锻造自动化生产线上63000 kN压力机的具体情况，同时为了避免因压力机检修平台占用较大的空间范围而对模具吊装造成的影响，提出采用两级传动的快速换模装置，节省成本的同时达到了快速换模的目的。此外，采用液压式夹模机构锁紧模架代替由T形螺栓加螺母预紧模架的传统形式，在拆卸及安装模架的过程中大大地减轻了操作人员的工作强度，提高了工作效率。经过生产验证，该快速换模技术可以明显提高齿轮锻造自动生产线上的换模效率，也为其他产品的锻造自动化生产线上的换模方案提供了借鉴和参考。     

网眼络纱管注射模设计

通过对网眼络纱管注射模的设计 ,阐述了该模具侧向型芯及导滑机构的设计方法 ,解决了该塑件多向抽芯的困难 ,并通过设计锁紧装置 ,保证了锁模的可靠性 ,从而保证了产品的质量     

板坯铸机结晶器夹紧装置的设计及应用

板坯结晶器是板坯连铸生产的关键工艺设备,在生产过程中激冷激热、温度梯度变化大,为此结晶器装置的设计、安装、调整等要求极为严格。其夹紧装置能够保证在浇注过程中获得高质量连续铸坯并且保持铸造腔形稳定。结晶器因框架结构不同,夹紧方式也有差异。结合VAI公司设计的板坯铸机结晶器的工况要求和结构特点,对U型框架弹簧拉杆类型夹紧装置的基本功能、使用要求、设计理念、工作原理、维修保养等几个方面进行了研究。     

Effect of sand mold models on the simulated mold restraint force and the contraction of the casting during cooling in green sand molds

In this work, the JIS AD12.1 (almost the same as A383.1) aluminum alloy was cast in a green sand mold. The restraint force from the sand mold and the contraction of the casting were measured dynamically from the solidifying temperature to the shake-out temperature using a dedicated device. Then, FEM (Finite Element Method) thermal stress analyses of the experiment were performed. The analyses adopted four types of representative constitutive equations and the mechanical properties of the green sand mold, which were quoted from previous research articles. As verification, this study dynamically compared the simulated restraint force and the contraction of casting with measured results and examined which mechanical properties are important for expressing the restraint force of the sand mold. This verification is the first attempt in the world. As a result, the simulated restraint force was estimated to be over ten times as large as the measured result in each type of equation because the yield stress of the sand mold used in our experiment was lower than those quoted from previous studies. The yield stress measured by a uniaxial compression test was 1/20 of the quoted values. When the measured yield stress was adopted in the simulation, the simulated restraint force and contraction approached the measured results. The yield stress of the sand mold was a dominant factor in the restraint force simulated by the thermal stress analyses. The yield stress of the green sand mold used in the casting process should be measured to predict the residual stress using FEM thermal stress analyses.     

Development of a device for dynamical measurement of the load on casting and the contraction of the casting in a sand mold during cooling

To predict and control the residual stress present in sand castings manufactured via CAE (Computer Aided Engineering), the mechanical interaction between the casting and the sand mold during cooling must be determined experimentally. A device was developed in this study to determine the load on the casting caused by the resistance of the mold and the contraction of the casting during cooling. Our device consists of two modules that work simultaneously: a module containing a load cell, for measuring the load on the casting during cooling and a module containing an LVDT (Linear Variable Differential Transformer) for measuring the contraction of the casting during cooling. In performance verification testing, the device enabled the simultaneous measurement of the load on the sand casting and the contraction of the casting. This measurement was performed dynamically during the cooling process. Additionally, for the case where the contraction of the casting was hindered by the sand mold, the permanent deformation of the casting after shake out (which leads to residual stress in the casting) was successfully measured using our device.     

Upscaling of the investment casting of the intermetallic alloy IC75

This research work is based on a specially developed SiO₂-free shell mold system for the investment casting of NiAl alloys. Hitherto, this shell system has only been used for scientific work on small, laboratory scale samples made of IC75 alloy. The main focus of the research is to examine the feasibility of upscaling of the shell mold system for production scale samples. For this reason, 200 mm long dummy turbine blades were cast. Nondestructive analysis of the castings by visual examination of the blades’ surface quality, computed tomography scans of their internal structures and three-dimensional measurements showed very good results for the shell mold system. In particular, the good dimensional stability of the shell mold with average deviations of +0.3 mm and a local maximum deviation of −0.73 mm are excellent for a water-soluble shell mold system. The results of this work demonstrate that the investigated mold system is suitable for large samples and melt weights of up to 5 kg and is thus adaptable for the production process of NiAl components.     

大方坯连铸结晶器水口优化模拟探究

为了研究不同浸入式水口类型对结晶器内流场流动的影响,以结晶器水口优化为出发点,利用物理模拟和数值模拟两种手段对断面280 mm×380 mm大方坯结晶器不同水口开展优化研究。本研究首先构建了一个1∶1结晶器水模拟试验装置,实现不同浸入式水口下的连铸流动模拟,利用PIV测量了不同水口下的结晶器截面流场,然后利用Fluent软件进一步研究了浸入式水口开孔角度、开孔数目、安装角度等参数变化对结晶器内流场以及液面波动的影响。物理模拟和数值模拟研究表明,开孔角度向上时,波动范围大于5 mm;开孔角度水平时,对窄面冲击速度过大,达到0.35 m/s;较双孔水口,四孔水口液面速度为0.22 m/s,小于卷渣临界速度值;水口安装角度改为对角线时,强化了内流场角部流动,整个流场流动更加稳定。     

固体火箭发动机燃烧室壳体纤维缠绕模具设计

介绍一种固体火箭发动机燃烧室壳体纤维缠绕芯模的设计。这项工作的目的在于提供一种可重复使用的纤维缠绕芯模。它采用的方法是钢模分瓣法。这种芯模的关键技术是芯模的组装和脱模。这项工作的意义在于提高纤维缠绕固体火箭发动机燃烧室壳体的比强度,节约生产成本,提高工作效率。     

A verification of the thermal stress analysis,including the furan sand mold,used to predict the thermal stress in castings

The restraint exerted on a casting by a furan sand mold on the casting and the contraction of the casting during cooling was dynamically and simultaneously measured using a device that we developed. The measurements were compared during cooling with thermal stress analyses. The thermal stress analyses were based on the representative mechanical models for the furan sand mold, i.e., the elastic and elasto-plastic models used in previous studies. The comparison demonstrated that the elasto-plastic model simulates the restraint force more accurately than the elastic model. In the thermal stress analysis, it was important to describe the development of inelastic deformation and the fracture of the sand mold. However, the simulated restraint force was still twice as large as the measured force even in the elasto-plastic model. This error is most likely attributable to using the temperature-independent mechanical properties of the furan sand mold and the mechanical model of the casting alloy, which neglected the viscoplasticity at high temperature in the thermal stress analysis.     

基于锁相环同步的晶闸管触发器的改进

针对采用锁相环倍频器构造同步电路的ZX5、ZL5系列晶闸管焊接电源,在实际应用中需要辨别相序接入电网的缺点,分析了原因,给出了无需分相序接入电网的改进方案,实验结果验证了方案的正确性。     

穿孔机转鼓压鼓器结构的改进

改进的穿孔机转鼓器结构,采用整体压鼓块和浮动丝杆,消除了螺纹间隙,提高了抗振性能。轧制时丝杆轴向受力减小一半,使转鼓被锁紧得更可靠。经两年多的实际使用证明,改进的穿孔机转鼓器完全能满足二次穿孔工艺要求,具有一定的推广价值。     

高密齿散热器型材挤压的数值模拟及模具结构优化

高密齿散热器型材由于其截面形状复杂、舌比值(悬臂∶齿间距)大而使其挤压模具设计难度大、试模成功率低。以某公司生产的高密齿散热器铝型材为例,采用数值模拟软件Hyperxtrude对其挤压成形过程进行分析研究。将原设计模具在仿真软件上进行虚拟试模,找出可能存在的问题,再结合实际试模情况和模拟结果对模具结构和参数进行多次优化。主要通过改变导流板角度和工作带尺寸,使得型材截面最大挤出速度与平均速度的比值趋近于1。结果表明:经优化后的模具消除了原来存在的问题,挤出了合格的高密齿型材。