双离合自动变速器电液控制系统油路间的相互影响及液压源参数的选择

为提高双离合自动变速器的工作性能,在分析自主研发的七速对置双离合自动变速器电液控制系统工作原理的基础上,利用AMESim软件,研究换挡过程中同时工作的液压缸间的相互影响及其影响因素,并通过选用合适的液压源参数的方法来降低相互影响程度。仿真结果表明:双离合自动变速器的电液控制系统中,两离合器作动油缸间的相互影响程度最大,并且两作动缸活塞截面积(活塞行程不变)、泵的排量、电机转速、蓄能器容积、油道水力直径等都会影响两缸相互影响的程度。     

基于逻辑分析法的本田自动变速器电液控制策略分析

运用逻辑分析法分析油路的走向和电磁阀的控制状态,将错综复杂的换挡油路过程简化为基本的逻辑表达过程,使得换挡过程更清晰,并用逻辑法表达自动变速器的油路走向过程.     

自动变速器换挡电磁阀设计及仿真研究

在分析自动变速器先导式换挡电磁阀工作特性、工作原理的基础上,对电磁阀的具体结构参数进行了设计计算,并建立了换挡电磁阀的AMESim仿真模型。仿真结果表明,根据所设计的换挡电磁阀得到的离合器压力变化曲线符合离合器接合过程压力变化规律,研究结果为自动变速器换挡控制奠定了基础。     

基于故障树的DCT故障诊断专家系统的研究

介绍双离合自动变速器常见故障模式。以"挂挡不能行驶"故障为例建立故障树并进行定性分析,求出全部最小割集。研究了双离合自动变速器故障诊断专家系统知识库构建和推理机实现等核心问题,如基于故障树的知识获取、知识表示方法、采用关系数据模型的数据库设计、基于规则的正反向混合推理过程等。研究表明:基于故障树的双离合自动变速器故障诊断专家系统设计合理,实用可行。     

基于故障树的DCT故障诊断专家系统的研究

介绍双离合自动变速器常见故障模式。以“挂挡不能行驶”故障为例建立故障树并进行定性分析,求出全部最小割集。研究了双离合自动变速器故障诊断专家系统知识库构建和推理机实现等核心问题,如基于故障树的知识获取、知识表示方法、采用关系数据模型的数据库设计、基于规则的正反向混合推理过程等。研究表明：基于故障树的双离合自动变速器故障诊断专家系统设计合理,实用可行。     

基于AMESim工程车辆变速器电液控制系统的仿真与试验研究

为了改善工程车辆变速器的换挡品质,对变速器电液换挡控制系统进行研究,利用AMESim软件建立仿真模型,分析主调压系统和离合器调压系统对油压的调节作用。以换挡过程中换挡离合器的充放油特性为切入点,采用遗传算法对换挡离合器主要结构参数进行优化,通过改善离合器充放油特性达到改善换挡品质的目的。设计和完成了变速器换挡油压特性试验进行了验证。结果表明:经过油压的调节及离合器结构参数的优化,换挡离合器的充放油特性明显改善,达到提高换挡品质的目的。     

自动变速器电液控制系统设计

对电控机械式自动变速器(AMT)的电液控制系统进行设计.电控机械式自动变速器是在原有机械变速器基本结构不变的情况下,通过加装电液控制换挡机构,取代原来由驾驶员人工完成的离合器分离与接合、摘挡与挂挡操作.最终实现换挡过程的操纵自动化.电液控制是自动换挡ECU通过控制电磁换向阀进而控制液压缸使换挡拉杆动作,实现换挡.     

柳州上汽获2000台变速器订单

柳州市重点项目——柳州上汽汽车变速器有限公司七速双离合自动变速器项目已复工,其中DCT380项目产线正在进行调试。首款DCT七速双离合自动变速器将为北京汽车配套,目前已获得首批2000台订单。据了解,此次建设的七速双离合自动变速器项目位于柳州阳和工业新区,投资3亿元,主要为上汽通用五菱配套生产汽车变速器,年产能可达30万台产能。据悉,柳州上汽基地厂房建筑面积18144m2,汽车变速器总成装配线3条,年设计装配能力为80万台,主要为上汽通用五菱以及扩展到西南地区的整车生产企业配套汽车变速器系列产品,同时还是上汽B系列发动机唯一配套的变速器总成供应商。     

装载机变速器液压系统分析

变速器液压系统对于变速器的性能有着重要影响。分析某装载机变速器的液压系统,包括主油压调压系统、换挡离合器,利用AMESim液压仿真软件建立了主油压调压系统、换挡离合器及整个液压系统控制模型,仿真结果表明该系统能够满足压力要求。并针对变速器液压系统分析了离合器结合、分离时序对换挡的影响,从而找到最佳的离合器结合、分离时序。     

电控机械式自动变速器液压换挡执行机构设计

在电控机械式自动变速器的设计中,换挡执行机构的设计是重点和难点,其性能的优劣,将直接影响整车的平顺性、舒适性和安全性。以某5挡手动变速箱为基础,根据换挡执行机构的设计要求,开发设计了一款电控液压式换挡执行机构。对液压系统进行了分析,设计了该换挡执行机构的液压系统,并对液压系统的主要元件进行了计算和选型;根据该换挡执行机构、液压原理图和选换挡液压缸分析了该换挡执行机构的工作过程;实际制作了该选换挡执行机构,并对对应的5挡MT变速器进行了AMT改造。试验表明：该选换挡执行机构能够实现该5挡变速箱的选挡和换挡,并且结构简单、定位准确、反应灵敏,换挡品质安全可靠,具有较好的推广应用价值。     

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.     

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.     

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.