基于AMESim的首绳更换装置液压系统设计与研究

针对当前多绳摩擦式提升机首绳更换过程中存在的问题，设计了一种“旧绳带新绳悬挂，新绳带旧绳回收”的履带牵引式首绳连续更换装置。利用AMESim仿真软件对液压系统进行建模仿真，并根据仿真结果对换绳装置进行了样机试制。结果表明：该首绳更换装置换绳速度稳定在0.59 m/s，满足首绳更换的效率要求；能够提供足够的摩擦力与夹紧力保证换绳过程的安全进行；在危险工况出现时能够以毫秒级的响应速度对装置进行保护。     

多速油缸及其回路

有些液压装置,往往需要油缸在运动中变换几种速度,例如机床的刀架油缸,工作台油缸等。一般情况下用节流阀或调速阀调节油缸运动速度,用换向阀进行速度换接。这样如果需要油缸有六种不同的前进速度和一种后退速度时,它必须采用3～6只节流阀(或调速阀),4～7只换向阀,这样势必使液压元件增多,而且液压系统也很复杂。如果按差动的原理,设计出特殊结构的多速油缸,并采用极为简单的回路,只用两个换向阀,就可以完成六进一退的七种不同的运动速度。油缸的结构如图所示,在油缸的主活塞     

基于AMESim和ADAMS的BHS首绳更换装置防冲击送绳技术仿真研究

为提高换绳装置送绳的安全性和可靠性,针对现有换绳装置在送绳过程中存在的冲击振动问题,分析其产生机制,提出了防冲击送绳理想控制曲线,并对现有换绳装置送绳液压系统进行改造,利用AMESim和ADAMS联合仿真技术对防冲击送绳系统进行仿真研究。仿真结果表明:采用防冲击送绳技术后,送绳过程冲击明显减小,有效解决了换绳过程中的冲击振动问题。     

多路节流阀

多路节流阀河北机电学院丁万荣石家庄大学赵华棉有多个执行油缸的液压系统，称多缸液压系统。若每个油缸在工作中均需调速，目前广泛采用的调速方法是使用多个节流阀，分别单独控制各油缸的运动速度。这样的系统液压元件多，结构复杂。本文阐述的多路节流阀可替代多个节流...     

步进式换带装置液压系统设计与研究

针对目前矿山井下巷道带式输送机胶带更换困难,研制了步进式换带装置,其特点是体积小、质量轻、易拆卸与安装。在现场进行调研并计算其参数,利用Automation Studio软件对换带装置液压系统进行模拟研究,分别得到固定防跑带压紧回路、移动压紧回路、拉带回路的工作油缸压力与活塞杆速度,结果表明该液压系统符合工况安全性要求。试制样机之后,对其液压系统进行优化,拉带时间由38 s缩短为31 s,提高了换带装置的工作效率。     

穿孔机顶杆循环装置液压控制系统的研究

设计穿孔机区域顶杆循环装置中顶杆小车油缸控制系统,对长行程高速重载液压系统油缸的速度、加速度、两腔液压力进行分析,对该类液压控制系统的运行机制、控制策略进行研究,进行了理论计算、仿真分析和实测验证,为类似工况液压控制系统的研究提供参考。     

采用步进油缸的结晶器振动装置动态性能分析

结晶器振动装置是连铸生产线的核心设备,结晶器振动装置分为机械式和液压式两大类。文章分析了机械式和液压式结晶器振动装置的优缺点,并重点分析和介绍一种一体式结构的结晶器振动装置-步进油缸的内部组成及工作原理。围绕为实现两个方向步进油缸控制性能的一致,结晶器振动装置工作点选取所需遵循的原则展开分析,对结晶器步进油缸工作点特性、系统稳定性及正弦响应特性进行分析和仿真。结果表明,步进油缸结晶器振动装置只有在确定的工作点,才能保证稳定性好,控制性能对称,为现场合理使用步进油缸提供了有效分析结论。     

基于AMESim稳罐装置液压系统设计与仿真分析

稳罐装置是超深超大矿井提升系统安全可靠运行的重要保护装置,防止超深超大矿井提升时提升容器的大幅震荡。为保证提升容器装卸载大吨位重物过程的稳定性、安全性,设计了稳罐装置液压系统,主要依靠单边装置2个升降油缸来柔性补偿钢丝绳形变量,利用AMESim对该系统进行建模并对升降油缸工况进行仿真分析,得到升降油缸的运行速度和压力变化曲线。结果表明:整个液压系统能够安全稳定运行,稳罐装置补偿速度能够满足提升工况需求。     

基于DSHplus的五轴加工中心滑枕平衡液压系统的仿真与设计研究

针对某厂五轴加工中心的滑枕平衡液压系统进行研究,设计一种新的滑枕平衡液压系统,使平衡油缸与滑枕的随动性能更好,快速响应机床加工过程中由于滑枕上下运动而带来的平衡油缸速度的变化。同时,通过DSHplus仿真软件对该液压系统进行了分析。     

采用比例流量压力复合控制的盾构掘进机液压推进系统

本发明公开了一种采用比例流量压力复合控制的盾构掘进机液压推进系统。它包括二位二通电磁球阀、比例调速阀、比例溢流阀、三位四通电磁换向阀、液压锁、平衡阀、压力传感器及带内置式位移传感器的液压油缸。推进系统中采用比例调速阀控制推进速度，采用比例溢流阀控制推进压力，通过合适的控制策略实现推进速度和推进压力的复合控制。     

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.     

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.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

电化学噪声数据处理方法概述

综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。