大型数控落地镗铣床主轴箱的有限元分析

通过三维软件建立了大型数控落地镗铣床主轴箱的三维模型,采用有限元软件建立了有限元计算模型,并进行了主轴箱的静态刚强度分析,计算了主轴箱的应力和变形情况.通过模态分析,计算了主轴箱1至10阶的固有频率和振型.分析结果表明,现有主轴箱的设计模型刚、强度较好,主轴箱的第1阶固有频率较低,相邻阶次的固有频率差别较大.     

加工中心主轴部件及其主轴箱的热特性有限元分析

现代机械工业对机床精度提出了越来越高的要求.机床主轴部件和主轴箱的热特性是影响机床精度的主要因素之一.文章建立了加工中心主轴部件及其主轴箱的温度场模型并进行了数字模拟仿真.首先预测了机床主轴部件的热平衡时间能,并以温度曲线的形式表示出来,然后计算出主轴部件和主轴箱的热变形.依据这些我们能够得到主轴的轴向和径向误差,为主轴部件的设计计算奠定了基础.     

基于有限元的精密主轴多目标优化设计研究

随着切削速度的不断提高,对主轴的动静态特性要求也越来越高。经验设计已不适应新产品的研制开发需要。在对精密主轴进行参数化建模的基础上,利用有限元扫描,分析各设计变量对状态变量和目标函数的影响。在有限元软件中建立了该主轴的多目标优化模型,通过比较优化前后主轴的性能可知:通过优化不仅提高了主轴的动刚度和固有频率,而且减小了主轴的质量,使结构参数更合理,能满足工程实际应用需要。     

组合机床主轴箱传动设计中主轴带动主轴的合理使用

本文对在组合机床主轴箱中主轴带动主轴的问题进行了分析和讨论，指出了如果对齿轮进行合理的传动设计，就可以用主轴带动主轴，而且不会增加主动主轴的负荷。     

不同性能机床主轴箱的比较研究

以两种不同性能磨床的砂轮架为例,对不同要求的机床主轴箱在设计、制造、装配等方面进行了详细比较研究与分析,揭示了机床主轴箱中各零件之间的相互内在联系,指出了砂轮架设计中如何对各种零件性能相互进行配合,从而满足不同性能机床主轴箱的要求。     

TK6920型数控铣镗床主轴箱的计算机辅助分析及改进设计

文章研究内容针对TK6920型数控铣镗床主轴箱CAD分析及优化,运用solidworks软件建立了三维CAD设计分析模型,并采用ansys有限元软件建立了有限元模型并进行静态刚强度分析.计算分析了主轴箱的应力及应变,在此基础上构建了主体结构的优化计算模型,将主轴箱进行了优化设计,尝试了新的改变约束的方法,与初始设计进行对比分析,为主轴箱的结构设计及改造提供理论依据.     

基于B/S的组合机床设计系统开发

利用PRO/E软件、SQL2005数据库和VS.net编程软件为开发平台,采用Top-Down技术,建立了组合机床的参数化三维模型图库并开发了基于B/S的组合机床异地设计系统.用户通过浏览器在组合机床设计系统的引导下可完成对组合机床设计的动力头功率计算模块、自动匹配组合机床模块、自动装配、生成三图一卡等总体设计和主轴箱等模块的详细设计,提高了产品的开发能力,缩短了产品的设计周期,降低了生产成本.     

基于有限元的140 kN摩擦焊机主轴箱响应面优化分析

以140 kN连续驱动摩擦焊机主轴箱为研究对象,应用有限元分析软件对主轴箱进行了静、动态相关特性的分析。为提高主轴箱综合力学性能,并实现主轴箱箱体材料的合理利用,以箱体壁厚等7个结构参数为设计变量进行了中心复合实验设计。根据得到的数据结果,基于Kriging插值法建立了主轴箱的响应面模型,并对各设计变量进行了灵敏度分析。利用多目标遗传算法完成了主轴箱的优化设计,与原结构方案相比主轴箱箱体减重16.6%,实现了焊机轻量化设计。经过对主轴箱响应面模型拟合精度的校验,验证了CCD实验法与Kriging插值法相结合可高效精准地完成主轴箱响应面模型的建立。因此这一优化方法同样适用于其他类型的机床零部件的设计。     

法国Renault公司多品种加工用组合机床

Renault 公司设计制造了几种适应中小批加工用的可调组合机床。图1为用于中小批生产的自动更换主轴箱的立式组合机床。该机床是采取自动更换主轴箱和分度回转工     

CAD技术在主轴箱设计中的应用

本文介绍了“组合机床BOK主轴箱CAD系统”的设计方法和功能特点。该系统在结构上,采用模块式结构设计;在程序算法上,采用自动优化设计和人机交互设计相结合的方法,可完成主轴箱的设计、校核、绘图和制表等。     

Prospects of the Use of Synergetic Approach to Solution of Problems of the Science of Nanomaterials

A synergetic approach to solution of problems of self-controlled synthesis of nanostructures and creation of self-organizing nanotechnologies is considered in connection with the superproblem of creation of materials with functional properties resembling those of biosystems. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 7, pp. 55 – 61, July, 2005.     

Kinetics of the oxidation of metals — Influence of self-diffusion of metal

The importance of the self-diffusion of a metal during its oxidation by a gas is treated for the cases of nonstoichiometric oxides having either interstitial cation or cation vacancies. We have established a general relationship for the reaction rate when a mixed diffusion process occurs. From this relationship, we have shown that the pressure dependence can be different, according to whether the rate-determining process is the self-diffusion through the metal or through the product.     

胫骨生物陶瓷复合材料的微结构增韧机理

扫描电镜观察显示胫骨是一种由羟基磷灰石和胶原蛋白组成的自然生物陶瓷复合材料.羟基磷灰石具有层状的微结构并且平行于骨的表面排列.观察也显示这些羟基磷灰石层又是由许多羟基磷灰石片所组成,这些羟基磷灰石片具有长而薄的形状,也以平行的方式整齐排列.基于在胫骨中观察到的羟基磷灰石片的微结构特征,通过微结构模型分析及实验,研究了羟基磷灰石片平行排列微结构的最大拔出能.结果表明,羟基磷灰石片长而薄的形状以及平行排列方式增加了其最大拔出能,进而提高了骨的断裂韧性.     

Features of formation of the structure in production of blanks of disks of heat-resistant nickel alloys

Conclusions To provide a high level of mechanical properties in wrought blanks of cast ÉP741NP and ÉP962 alloys it is necessary to form controlled structures. A necklace-type structure formed in homogenizing isostatic treatment, subsequent thermomechanical working including alternation of the operations of deformation in the (+)-area and recrystallization anneals, and final heat treatment is preferable. The temperature conditions of all stages of thermomechanical working are strictly controlled, especially the final operation of deformation and heating for hardening. To eliminate hardening cracks and distortions it is necessary to use molten salts at t=600°C as quenchants. The use of multiple production operations makes it possible to significantly reduce the structural inhomogeneity related to inhertance of the original dendritic structure. However, the structure of the final semifinished product is nevertheless characterized by a difference in occurrence of the processes of polygonization and recrystallization between the former dendritic cells and the interdendritic spaces in deformation and heat treatment.To obtain structurally homogeneous blanks for gas turbine engine parts it is necessary to use basically new methods of remelting such as vacuum double electrode remelting and electron beam remelting with an intermediate vessel.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 12, pp. 25–29, December, 1991.     

Ab-initio calculation of enthalpies of formation of intermetallic compounds and enthalpies of mixing of solid solutions

A large number of ab-initio calculations of energies of formation of intermetallic compounds have been performed in the last 15 years. The currently used methods are listed. The paper presents a review of the aluminium based compounds which have been studied. Comparisons of calculated and experimental enthalpies of formation are provided for aluminim-3d and-4d transition metal alloys at equiatomic composition. The modelling of the enthalpies of mixing of solid solutions based on a given lattice is described.     

试论洋务派教师聘任的思想

洋务派在洋务学堂的办学活动中,为了解决西学专业学科的教学困难,采用了聘请外籍教师的应急措施.他们以真才实学,合同制管理作为主导思想,并认为这种解决师资的途径只是权宜之计,并非久远.从客观上看,洋务派的教师聘任思想有深刻的历史影响.     

Mechanism of Nucleation of Precipitates of Carbides of Refractory Metals Under Hot Rolling of Automotive Sheet Steel

Metal Science and Heat Treatment - The problem of formation of properties in microalloyed sheet steels is considered. The cause and the possible mechanism of precipitation of carbides of refractory...