锥罩车头部圆弧夹具的改进

原锥罩车小端圆弧夹具采用螺纹夹紧,尽管具有结构简单、装卸工件方便、压紧力易于控制,但生产效率较低的特点,不适合大批量的生产要求。通过采用快速夹紧机构,对锥罩车小端圆弧夹具进行了改进。改进后的夹具不仅具有结构简单、装卸工件方便等特点,而且生产效率较高,满足了大批量生产的要求。     

抽油烟机油杯的激光焊接机构设计

针对抽油烟机油杯组件的激光焊,设计了焊接夹具,主要由顶紧组件、夹紧组件和旋转组件等三部分组成。其中,顶紧组件中的凹形台阶对工件进行精确定位,夹紧机构在焊接前对工件进行固定,减小焊接过程中工件的变形,旋转机构起到驱动工件运动的作用,实现激光焊。文中设计的夹具系统在抽油烟机油杯焊接的实际生产中得到应用,焊接件满足使用要求,取得了良好的焊接效果。     

一种多点浮动夹紧可自锁夹具

介绍了一个机构紧凑、新颖,带自锁的10点浮动夹紧的夹具结构,实践表明该夹具成功的解决了一个整体毛坯,切开成5个零件,在切开过程中及分离后,每个零件仍保持了牢固的定位和夹紧,该机构对有类似夹紧要求的夹具设计有一定的指导意义。     

液压夹紧的随行夹具

目前常见的带随行夹具的自动线,工件在随行夹具中的夹紧大多为机械夹紧方式。 1966年,我院为上海跃进电机厂设计了一条JO_3系列电机座加工自动线。根据工艺要求,在自动线上采用了一种液压夹紧的随行夹具。经几年来的生产运行考验,此随行夹具基本上满足了工艺要求。     

四千马力柴油机主轴承盖两端面铣削夹具

该夹具满足了如下要求:1)自动定位夹紧;2)夹具可在两铣刀间通过;3)便于机械手装卸;4)自锁。为保证对工件有足够的夹紧力,采用了杠杆增力机构。图1幅。     

弹力锁紧式气动夹紧装置的研究

详细介绍一种弹力锁紧式气动夹紧装置。该装置中,将传统气动夹具的充放气功能对调,采用夹紧弹簧代替气压作用力夹紧工件。阐述该装置的结构原理、设计要点及特点。与传统气动夹具对比可知,该新型气动夹紧装置具有可靠性高、安全性好等优点,特别适合一般生产条件的机械加工厂改制。     

钻削类组合机床夹具夹紧机构的计算机辅助设计

本文针对加工箱体类零件钻削类组合机床,论述了夹具CAD与机床三图一卡CAD的数据接口,提出夹具结构模型与工件受力模型,并分析归纳了典型受力情况下工件所需夹紧力的计算公式,最后提供了几种常用夹紧机构的选择.其特色在于将夹具设计的原始数据、夹紧力计算、夹紧机构的选择程序化,形成钻削类组合机床夹具夹紧机构CAD的软件包。     

下芯夹具在缸体组合芯上的优化设计

简述了缸体砂型铸造流水线下芯夹具应用现状,以及使用中存在的不足之处.经过多次试验、设计,运用动态仿生学对下芯夹具的结构做出局部调整,即平移机构代替杠杆机构.阐述了采用多层式下芯夹具的齿条带动齿轮平移运动机构以及夹紧机构同步性等的优化设计.在实际生产中,取得了良好的效果.在一定尺寸的铸件成型中,具有通用性.     

汽车发动机缸体自动清洗专用机床设计

针对某发动机缸体机械加工后清洁度存在的问题及控制要求,在分析机器人清洗及专用机床清洗工艺及应用特点之后,选择"专用机床+旋转变位机+可换定位机构"的工艺及设备方案;根据确定的工艺方案,在充分考虑加工及上下料方便、自动化程度及密封等因素的基础上,确定了采用"十字"数控滑台拖动清洗水枪、旋转变位机自动定位夹紧工件并对工件清洗过程进行准确变位及采用上下料机构进行自动上下料的立式专用机床整体布局方案;设计了设备专用夹具、上下料机构等的结构。实际生产表明:单台设备实际年生产纲领达到13万件左右,生产效率及清洁度均达到设计要求。     

一种三腔液压油缸夹紧机构

一种三腔液压油缸夹紧机构大连机床厂靳玉伟在组合机床夹具设计中，经常要进行夹紧机构的设计。为提高生产率，我们设计了多腔夹紧机构，以适应不同工件的夹紧要求。针对有的工件需要夹紧力大且压杆行程大的特点，设计了一种三腔液压油缸夹紧机构，如图所示。夹紧力Ｑ的计...     

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.     

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。     

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.     

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.     

Structural Optimization of Electromagnetic Swirling Flow in Nozzle of Slab Continuous Casting

During the slab continuous casting process, the flow field of molten steel in the mold plays a decisive role in the quality of the slab. In this paper, electromagnetic swirling flow in nozzle technology is proposed to control the flow field in mold.This technology can drive molten steel to rotate inside the submerged entry nozzle by electromagnetic force, thereby controlling the flow field. This research shows that it can reduce the impact of molten steel on the bottom of nozzle and partly reduce the negative pressure at the upper part of nozzle outlet which is even eliminated by optimizing the structure and angle of nozzle. The area of heat flux of the mold wall becomes larger, and the crest value of heat flux gets lower than that without swirling in nozzle and any nozzle optimization. The meniscus fluctuates smoothly, and the flow velocity at the top surface is within a reasonable range. The temperature field distribution in the mold is uniform which was beneficial to the growth of equiaxed crystal and decreased element segregation.