基于ADAMS的多级液压油缸建模与仿真

介绍了多级液压油缸的结构和工作原理,利用ADAMS软件,通过将多级液压油缸分解成多个单级液压油缸,建立了多级液压油缸机械-液压耦合动力学仿真模型。以某型号矿用自卸汽车为例,进行了液压举升系统的仿真,并进行了现场试验,试验结果验证了仿真模型。仿真和试验结果表明,多级液压油缸工作中,在各级缸筒伸出瞬时,液压油缸无杆腔内会出现较大的液压冲击。     

大型矿用自卸车举升液压系统设计与仿真

针对大型矿用自卸车举升液压系统高压、大流量的特点,借鉴国外同类车型举升液压系统原理,设计了由6个盖板式插装阀和2个螺纹插装阀组成的新型举升液压系统原理图,实现举升、停止、下降和浮动4个动作。以某大型矿用自卸车为例,利用Automation Studio仿真软件,对举升液压系统进行建模和仿真,得到该车在货厢举升过程中,举升油缸位移、无杆腔和有杆腔油液压力随时间的变化曲线。由仿真结果可知:各级油缸伸出时、由举升转换至停止和停止转换至下降时均存在压力冲击,最大冲击峰值为29.0 MPa。     

变转速闭式泵控系统在纯电动专用车中的应用研究

电动化是专用车辆的发展趋势,但是动力电池体积大、充电时间长以及成本高等缺点也是制约纯电动专用车发展的因素。目前专用车作业装置中液压驱动大多采用阀控系统,造成系统能耗较高,电池能量利用率也低,不利于整车的降本增效。针对此种问题,提出一种VSCPC（变转速闭式泵控）系统并将其应用在自卸车举升机构。仿真结果表明：该泵控系统运行正常,液控单向阀和蓄能器能够实现非对称的流量匹配,有效减少节流能耗。此外,车厢势能通过VSCPC系统反馈至电池,降低举升能耗约3168%,进一步提升纯电动专用车的节能优势。     

基于AMESim的自卸汽车举升机构的建模与仿真

以前置直推式自卸汽车举升机构为研究对象,利用AMESim软件建立举升机构液压系统模型。根据整个机构的几何关系计算举升过程中负载的变化;设置一些主要的参数,对整个举升机构进行仿真。根据仿真结果得出液压回路压力对举升缸的影响。这种方法较以往的编程建模方法和软件协同建模方法更加简便和有效,具有一定的推广价值。     

基于AMESim的泵车水泵液压系统流量匹配装置设计与研究

清洗水泵是泵车上必不可少的装备,水泵实际须配的功率很低(约3 k W),而泵车发动机功率很大(287 k W),现所有泵车水泵的液压系统,均采用定量泵-定量马达系统,在发动机高速运转、定量齿轮泵系统流量很大时,水泵将泵出高压水,而发动机怠速、系统流量低时,系统基本没法正常泵水工作。针对此问题,提出了一种定量泵-定量马达系统流量匹配的设计方法,该方法能保证水泵系统在泵车发动机从怠速到全速各工况下,均能正常工作、泵出高压水,并且利用AMESim软件,建立流量匹配装置的仿真模型,对流量匹配装置工作的动态特性进行仿真分析。仿真结果表明,该系统的动态工作性能完全满足设计的要求。     

升系统平衡阀定阻尼孔设计研究

针对于一种车载举升系统平衡回路中平衡阀的阻尼孔参数对液压系统回路的影响进行了研究,分析了平衡回路和平衡阀的工作原理,采用AMESim仿真软件建立举升系统液压平衡回路模型,仿真分析了平衡阀在不同内部定阻尼孔直径下液压平衡回路的动态特性,由仿真结果得到定阻尼孔设计原则,为此类平衡阀的设计与改进提供一定参考。     

举升系统平衡阀定阻尼孔设计研究

针对于一种车载举升系统平衡回路中平衡阀的阻尼孔参数对液压系统回路的影响进行了研究,分析了平衡回路和平衡阀的工作原理,采用AMESim仿真软件建立举升系统液压平衡回路模型,仿真分析了平衡阀在不同内部定阻尼孔直径下液压平衡回路的动态特性,由仿真结果得到定阻尼孔设计原则,为此类平衡阀的设计与改进提供一定参考。     

新型液压系统分析仪在矿用自卸车故障诊断方面的应用

介绍新型液压系统分析仪在线快速检测矿用自卸车液压举升系统故障的方法。通过T型接头将分析仪接入所测液压系统,封闭相关的液压系统油路,进行加载可测试液压系统中的液压泵、控制阀及液压缸的性能参数,从而诊断出系统故障。该方法也可应用于其他类型的液压系统。     

串联式液压混合动力车辆能量管理策略的设计与分析

以重型串联式液压混合动力汽车为研究对象,提出了基于规则的能量管理策略,并对整车设计了4种工作模式。搭建了其Matlab／Simulink整车仿真模型,对液压混合动力车辆总需求功率、发动机功率、液压系统回收功率、蓄能器流量、 SOC （ State of Charge）等参数进行了仿真,分析对比了传统汽车和液压混合动力汽车发动机扭矩工作点。仿真结果表明：液压混合动力汽车发动机和液压系统提供的功率可以满足总需求功率要求,其燃油经济性显著提高, SOC保持在合理范围内,发动机工作平稳,所设计的能量管理策略可靠有效。     

某型装备液压快速顶升及试验装置优化设计与仿真

针对某型装备维修空间小、应急维修功能缺失等特点,设计一种可移动式的液压快速顶升及试验装置;建立液压顶升装置AMESim仿真模型,通过9种运行工况下的模拟仿真,优化了液压快速顶升及试验装置的设计参数;考虑到流量阀调节作用以及系统沿程损失,设备设计溢流阀压力22 MPa、泵流量3 L/min、电机功率1. 5 k W。优化后的液压快速顶升及试验装置能良好地完成装备顶升及液压部组件的试验任务。     

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.     

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.     

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。     

A STUDY OF TEMPERATURE-DEPENDENT VALENCE BOND STRUCTURE OF TITANIUM

On the basis of energy and shape method for the determination of the valence bond (VB) structures of crystal, the valence bond structure of titanium is redetermined at room temperature and calculated in the whole temperature range of 0-1943K. The outer shell electronic distribution of Ti is e_c~(2.9907) · (s_c~(0.4980) d_c~(2.4927)) ef1.0093 in crystal. The temperature dependences of the VB structures of hcp and bcc phases are the same. The VB structures of hcp and bcc phases monotonically increase or decrease with the increase in temperature, but show discontinuous changes at the phase-transformation temperature 1155K.