解决反旋测长的一种新方案

强力旋压机床在加工工件时根据工件的不同有两种旋压方法:对于带底的筒形件采用正旋,即金属流动方向与旋压方向相同。对于不带底的筒形件采用反旋,即金属流动方向与旋压方向相反。对于正旋,旋压成形长度与进给量一致。而对于反旋,旋压成形长度等于进给量与金属反流量之和。由于金属反流量与金属变形量有关,因而对于同一旋匝参数来说,其往往也不一致。目前,大多通过理论计算和反复实践才取得一近似值,这给实际加工和提高工件精度带来了不少困难。     

强力旋压反旋自动跟踪装置

强力旋压是具有无切削、材料利用率高、表面光洁度好、尺寸精度高和能够细化晶粒、提高零件强度等优点的压力加工新工艺。强力旋压按金属轴向流动方向,又可分为正旋和反旋两种。在机械加工行业中,有大量不带底多台阶的薄壁筒形件或任意曲     

筒形件强力旋压有限元模拟研究

筒形件强力旋压是一种连续的局部复杂变形过程。采用动态显式有限元程序LS-DY-NA3D对筒形件强力旋压进行了三维有限元模拟,对有限元建模关键问题进行了研究,通过试验验证了有限元模型的合理性。以旋压力和最大等效应力为研究对象,研究了工艺参数和模型参数对模拟结果的影响。模拟结果和实验结果具有较好的一致性。     

筒形件数控旋压加工仿真的研究

在研究筒形件强力旋压变形的基础上 ,对在 Auto CAD环境中数控加工仿真的方法和步骤进行了详细的描述。运用三维图形技术实现了对旋压加工的动态模拟。这种仿真方式不同于以往的切削加工仿真 ,根据工件体积不变的原则和加工中金属的流动规律对整个加工过程进行动态模拟 ,为数控加工的仿真提出了一种新的方法     

筒形件强力旋压中扩口的防止

筒形件强力旋压中的扩口或称为“喇叭口”(如图1所示)是旋压中的主要缺陷,严重地影响旋压件良品率的提高。因此,减小扩口的长度或防止扩口段的形成是旋压工艺需解决的问题。     

镍基高温合金筒形件毛坯错距旋压工艺研究

GH4169镍基高温合金筒形件流动旋压成形的难点是在大长径比、变壁厚的情况下保证内径精度。论述了该件流动旋压成形的工艺路线的制定、试验方法。在旋压过程中采用了错距旋压,探索了错距流动旋压的工艺参数对尺寸精度的影响,为该类产品的旋压成形提供了技术支持。     

薄壁筒形件错距强力旋压成形的工艺研究

通过双旋轮错距强力旋压成形薄壁筒形件的工艺研究,对错距旋压过程中旋轮轴向错距值的选择、进给比、冷却、润滑进行了讨论,对旋压缺陷进行了分析,解决了旋压过程中出现的问题,达到了工件质量要求。     

气瓶坯料错距反旋成形的工艺研究

简述了气瓶坯料筒形件流动成形的工艺路线的制定、试验方法,旋压过程中采用反旋错距方法,探索了反旋错距流动旋压的工艺参数对尺寸精度的影响,为气瓶坯料旋压成形提供工艺支持。     

两种薄壁筒形件旋压工艺改进中的真空热处理试验

正为了提高原材料的利用率,对30CrMnSiA钢薄壁筒形件进行了旋压成形工艺改进。在试行旋压前对坯料调质、旋压后不淬火的工艺改进方案时,对坯料进行了真空调质处理的试验。在试行旋压后淬火的工艺改进方案时,又进行了薄壁筒形件旋压后的真空淬火、井式炉淬火等工艺试验。经过试验对比,最后以旋压后真空淬火的工艺方法,取得了工艺改进试验的成功。一、零件概况一种直径较大的薄壁筒形件如附图所示,材料为30CrMnSiA钢。要求力学性能满足抗拉强度Rm≥1080MPa,伸长率A≥10%。这种筒形件原先     

筒形件强力旋压中胀径问题

在旋压加工中,影响筒形工件胀径和精度的因素很多,例如工艺参数的选择;旋压机的结构型式、精度和刚度;坯料的材质、壁厚差的大小以及它与芯模的配合间隙;芯模的精度和硬度及其安装精度;加工过程中的冷却状况等。筒形件强力旋压因工艺参数选择不佳而胀径、尺寸超差,是影响成品率的主要原因。     

机械传动部件扭矩反馈效应的研究

本文以数控机床进给驱动系统为例,从理论分析、数值分析和实验分析三方面论述了机械传动部件的扭矩反馈效应,从而为机床进给驱动系统的设计、分析和控制提供了这方面的科学依据。     

三维非轴对称零件旋压成形机理研究

提出采用旋压技术直接加工各部分轴线间相互平行或成一定夹角的三维非轴对称薄壁空心零件的工艺方法,探讨了该成形技术的工作原理、成形过程的特点及变形机理,并预测了其推广应用前景。提出的旋压成形装置可使旋轮在随机床主轴作回转运动的同时,沿垂直于机床轴线方向作径向进给运动。     

通道锥度对透平导向叶片绕流性能的影响及这种大锥度叶片设计方法的改进

本文对透平常用的锥形通道中的三元流动进行了初步探索,文中第一部分研究大锥度扩张（收缩）型透平导叶通道中、在上下游都没有动叶的条件下,锥度对叶栅性能的影响。结果表明：在设计中需要考虑由于实际流面偏离圆柱面所引起的出气角的变化,为此,本文给出了近似计算出气角变化的方法。文中第二部分对上述透平导叶提出了考虑三元流动的近似设计方法。     

ANALYSIS OF MECHANICS IN BALL SPINNING OF THIN-WALLED TUBE

Ball spinning is applied to manufacturing thin-walled tube with high precision and high mechanical properties. On the basis of plastic mechanics, by simplifying ball spinning of thin-walled tube as plane strain problem, slab method is used for the purpose of calculating the contact deformation pressure. The spinning force components, the torsional moment, the deformation power and the deformation work are calculated further as well. The influence of the two important process parameters such as the feed ratio and the ball diameter on the spinning force components is analyzed in order to further control the spinning force components by regulating the two process variables during the ball spinning process. The stress and strain state in deformable zone as well as mechanics boundary conditions in ball spinning are obtained. The effect of the three spinning force components on the formability of the spun part is analyzed and validated through the ball spinning experiments. The theoretical and experimental results show that the radial spinning component plays a significant role in ball spinning of thin-walled tube, and the mechanics situation in backward ball spinning contributes to enhancing the plasticity of the metal material, but that in forward ball spinning contributes to advancing the axial flow of the metal material.     

ANALYSIS ON THE SPINNING FORCESN IN FLEXIBLE SPINNING OF CONES

Flexible spinning is a new type of spinning process where spin-forming is performed without using a mandrel. Combining shearing and rolling processes, the calculation formulas of the spinning forces in flexible spinning of cones is presented. The effects of the main processing parameters, such as gripping force G applied to the blank by the inner roller, the feed rate of rollers f and theroundness radius of outer roller ro, on the spinning forces are analyzed experimentally and theorelically.     

ANALYSIS ON THE SPINNING FORCES IN FLEXIBLE SPINNING OF CONES

Flexible spinning is a new type of spinning process where spin-forming is performedwithout using a mandrel. Combining shearing and rolling processes, the calculation formulas of thespinning forces in flexible spinning of cones is presented. The effects of the main processing parame-ters, such as gripping force G applied to the blank by the inner roller, the feed rate of rollers f and theroundness radius of outer roller r_o, on the spinning forces are analyzed experimentally and theoreti-cally.     

后曲叶片抛丸器运动学参数和叶片所承受正压力的计算

本文提出了后曲叶片抛片丸器在考虑摩擦情况下的运动学参数和弹丸作用于叶片上正压力的计算方法。     

超声波振动修整砂轮的耐用度研究

本文就平面磨削,外圆磨削及内孔磨削时超声波振动修整砂轮的耐用度问题进行了深入地研究。     

60Si2Mn钢曲母线形件强力热旋压成形技术研究

针对60Si2Mn钢曲母线形件材料利用率低的问题,研究了该类工件的成形工艺。采用旋压工艺替代切削工艺,直接成形曲母线形件,能够提高原材料的利用率,并获得良好的组织性能。分析了高碳钢热旋压工艺难点,开展了旋压试验研究,确定了加热强力旋压的工艺方案,试验分析了旋压温度、变形量和上下料时间等工艺参数,掌握了旋压规律,并旋压出了合格产品。对旋压样件进行了性能及金相分析,试验结果达到了产品设计要求,材料利用率由50%提高到了70%。     

COMPUTER SIMULATION OF BELOW-CENTER AND ABOVE-CENTER CENTERLESS GRINDING

Centerless grinding of ceramic components in the conventional above-center mode under aggressive conditions often results in workpiece spinning. One way to avoid workpiece spinning is to use below-center grinding, but this can lead to problems with part rounding and lobing. The present investigation was undertaken to develop a practical simulation to assist in the selection of acceptable set-up conditions for centerless grinding. From the initial workpiece profile and set-up conditions as input, the simulation predicts workpiece spinning and the progressive change in the workpiece profile for both above-center and below-center grinding. Simulation results for workpiece lobing were found to be consistent with experimental results obtained for below-center grinding of zirconia specimens.