基于FCS和多模式预测控制的25MN快锻液压机组控制系统研究

介绍了25MN快锻液压机组的组成及其工作原理,针对快锻液压机组的生产工艺要求,提出了由工业控制计算机和PLC组成的现场总线控制系统(FCS)网络结构;针对其控制上的快速性、平稳性和高精度的要求,设计了一种多模式预测控制系统,实现了其活动横梁平稳、无冲击和准确的位置控制.     

运用PLC和PID的液压机同步平衡系统的研究

以S7-300 PLC作为核心搭建液压机溢流补偿型同步平衡控制系统的试验平台,通过将模具安装在工作平台偏心的位置使液压机偏载活动横梁产生偏斜,当对角偏差量大于某一设定值时启动同步平衡系统纠偏,调整PID模块的控制参数使溢流补偿型同步平衡控制系统达到最优的纠偏效果,对比分析活动横梁对角偏差以及纠偏缸上下腔的压力和流量的试验曲线。结果显示,其同步平衡系统精度能达到0.030 mm.m-1,调节时间小于2.9 s,满足同步系统设计要求。     

免疫PID算法在10-2000型等温锻造液压机中的应用研究

针对某型号等温锻造液压机滑块速度的控制要求,提出基于免疫控制的PID算法,设计出免疫PID控制器并应用于等温锻造机的滑块速度控制中,仿真结果和系统实际运行效果表明:免疫PID控制性能要优于传统PID控制,具有较高的控制精度和较强的鲁棒性,且满足等温锻造液压机滑块速度的控制要求。该技术已成功应用于大型数控薄板冲压液压机的控制系统中。     

PLC和触摸屏在龙门式液压机组控制系统中的应用

根据球罐弧形板片成形冲压工艺要求,构建了龙门式液压机组控制系统主站PLC与远程站ET200S和工业监控设定触摸屏HMITECH TPC-150TC之间的网络架构,设计了主站PLC与触摸屏的软件程序,重点阐述了主泵电机软起动和数据处理与整定程序设计过程,同时对触摸屏画面组态设计进行说明。系统主站PLC通过对现场数据的采集分析处理,实现了压机快下、加压、停止、回程、快回控制执行功能。经现场调试与实际应用,程序各功能块运行准确,能完成预期的控制功能。     

350 MN多向双动挤压液压机活动横梁纠偏调平策略

为满足大型精密模锻件的成形工艺需要,须在大型模锻液压机上装备纠偏装置或调平系统,使活动横梁在偏心载荷下达到一定的水平精度。结合一台具有模锻功能的350 MN多向双动挤压液压机研制、创新液压机结构和控制系统设计,从技术可靠、简单、适用和低成本角度,探讨了活动横梁基于对偏心载荷响应的纠偏调平策略。将回程缸与主缸一起构成一个纠偏力自适应调平系统。按偏心力矩产生的方位,使其中的1个或2个回程缸升压、使相对应的主缸旁路卸压,组成闭环调节回路,可使活动横梁的动态水平度控制在允许范围内,系统简单可靠、装机功率低、运行效率高。     

24MN玻璃钢制品液压机控制系统的研制

24MN玻璃钢制品液压机有其特殊的工艺要求,需要对液压机的压力、速度和平度进行控制.为此设计了液压系统的结构,采用八缸框架式结构,并提出PLC与Trio控制器相结合的控制方案.PLC主要负责系统运行、维护与模式切换.Trio控制器依靠设计的控制算法,调节比例伺服阀,以控制压力、速度和平度.通过调试,系统运行良好并实现了要求的控制目标.     

具有双移动工作台的汽车车门折边液压机

近日，合肥锻压机床股份有限公司３台YH２５－２００E型汽车车门折边液压机安装调试完毕，并通过用户现场验收。该型号液压机突出的标志就是机床两侧各有一个移动工作台。当一个工作台工作时，另一个可以进行下一副模具的安装，大大节省了换模时间，提高了生产效率。该型号液压机外观为立式四柱结构，由机身、主油缸、侧缸、提升夹紧缸、双移动工作台、锁紧机构、行程限位装置、液压动力系统及电气控制系统等部件组成。机身由上横梁、滑块、下横梁用四根立柱相连，液压系统采用了先进的二通插装阀系统，电气控制系统选用了国际上先进的PL…     

PLC在液压机控制系统改造中的应用

将YA32—315型四柱式液压机由继电器控制改为可编程控制器（PLC）控制,对原有下顶出缸的液压油路控制系统进行改进,通过高精度比例溢流阀和PLC的模拟输入输出模块对顶出缸的油压进行控制,并结合板材变压边力成形工艺,在单动液压机上实现变压边力控制。在板材成形过程中通过可编程控制终端对成形力、压边力及凸模行程进行实时监视和控制。     

两种2000kN液压机故障分析及改进

液压机是锻压、冲压、冷挤、校正、弯曲、粉末冶金成型等工艺中被广泛应用的压力加工机械，是最早应用液压传动的机械之一。它一般要求液压系统完成的基本动作为：滑块快速下行、慢速接近工件、保压、卸压、快速回程及在任意位置停止；如果液压机具有顶出油缸，则另有顶出...     

120MN超大台面玻璃钢液压机的研制

本文针对玻璃钢成形工艺的特点,结合客户需求开发了120MN超大台面7000mm×5000mm玻璃钢液压机。结合现有的重型液压机各种机架结构形式进行分析综合评估,最终选择工艺性较好、便于生产制造的预应力拉杆框架结构作为主体机架结构。机身经过有限元分析优化设计,保证刚度和强度。采用多缸均布结构,上横梁滑块等受力部件受力均匀,非常适合玻璃钢缓速成形工艺。液压控制系统集成了开模缸控制系统动态调平技术、蓄能装置恒压控制技术、多泵合流控制技术、泵保压控制技术、吨位分级控制技术等多项核心技术。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

THERMODYNAMICS STUDY ON THE DECOMPOSITION OF CHROMITE WITH KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

INFLUENCE OF HEAT TREATMENT ON DAMPING BEHAVIOUR OF THE MAGNESIUM WROUGHT ALLOY AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

An Easy Way to Quantify the Adhesion Energy of Nanostructured Cu/X(X=Cr,Ta,Mo,Nb,Zr) Multilayer Films Adherent to Polyimide Substrates

An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.     

High-Speed Friction Stir Welding of SiC_p/Al–Mg–Si–Cu Composite

A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.