渐开线螺旋花键的滚压加工

阐述了渐开线螺旋花键的滚压原理、坯料计算、工装设计及材料的选择，对滚压加工进行了很好的研究。实践表明，采用滚压技术加工的渐开线螺旋花健，不仅极大地提高了生产效率，且制件的质量也大为提高。     

Prediction of flank wear by using back propagation neural network modeling when cutting hardened H-13 steel with chamfered and honed CBN tools

Productivity and quality in the finish turning of hardened steels can be improved by utilizing predicted performance of the cutting tools. This paper combines predictive machining approach with neural network modeling of tool flank wear in order to estimate performance of chamfered and honed Cubic Boron Nitride (CBN) tools for a variety of cutting conditions. Experimental work has been performed in orthogonal cutting of hardened H-13 type tool steel using CBN tools. At the selected cutting conditions the forces have been measured using a piezoelectric dynamometer and data acquisition system. Simultaneously flank wear at the cutting edge has been monitored by using a tool makers microscope. The experimental force and wear data were utilized to train the developed simulation environment based on back propagation neural network modeling. A trained neural network system was used in predicting flank wear for various different cutting conditions. The developed prediction system was found to be capable of accurate tool wear classification for the range it had been trained.     

渐开线花键轴无屑加工研究

介绍了渐开线花键轴无屑加工(冷挤压工艺),对冷挤压的成形原理、工艺分析、毛坯设计、模具及重要型腔的设计进行了阐述.结果表明:渐开线花键轴采用冷挤工艺可行,产品质量好,生产效率高,产品成本低.这能为类似零件的加工工艺提供参考.     

High-speed five-axis milling of hardened tool steel

This paper investigates critical issues related to high-speed five-axis milling of hardened D2 tool steel (hardness HRc 63). A forging die cavity was designed to represent the typical features in dies and molds and to simulate several effects resulting from complex tool path generation. Cutting tool materials used were coated carbide for the roughing and semi-finishing processes and polycrystalline cubic boron nitride (PCBN) for the finishing process. The effects of complex tool paths on several critical machining issues such as chip morphology, cutting forces, tool wear mechanisms, tool life and surface integrity were also investigated. The main tool failure mode was chipping due to the machine tool dynamics. A five-axis analytical force model that includes the cutter location (CL) data file for computing the chip load has been developed. The effect of instantaneous tilt angle variation on the forces was also included. Verification of the force model has been performed and adopted as a basis for explaining the difficulties involved with high-speed five-axis milling of D2 tool steel.     

基于ANSYS Workbench的冷敲机花键轴模态分析

花键轴是花键冷敲机分度机构与滚打机构的连接轴,是冷敲机微量进给系统的重要部件。以花键冷敲机的花键轴作为研究对象,采用SolidWorks对其进行建模,并利用ANSYS Workbench对其进行模态分析。提取前5阶固有频率以及与之相对应的振型,通过对振型图进行分析,发现了花键轴振幅较大的问题,并设计出减小花键轴振幅的装置。对花键轴的不同位置施加约束,并进行模拟分析,得出其固有频率的变化规律,说明采用浮动的约束装置对花键轴有振动补偿控制作用,改善了花键轴的刚性和设备运转的稳定性,大大提高了生产效率和花键的机械性能。     

六面顶压机冷却功率控制系统的设计

提出一种通过控制六面顶压机冷却水的冷却功率来提高金刚石合成块温度控制精度的方法,设计了精度达0.5%的三线制热电阻温度采集电路、脉冲型涡轮流量计的信号采集电路和步进电机驱动电路。在STM32平台上,实现了步进电机的加减速控制和高精度脉冲频率的测量。结合带死区的增量式PID控制算法,获得了良好的冷却功率控制效果。     

圆筒形部件变形评价模型及方法

圆筒形部件变形是工程实践中经常碰到的问题,定量地评估其变形程度对于指导工业生产具有重要的意义。提出了圆筒形部件变形评价指标,引入三次样条插值方法建立了工程化的指标计算方法,计算了飞机进气道/发动机之间圆筒形过渡段在三种不同状态时变形评价指标,并实际装机验证对比。结果表明:指标的评价结果与实际装机验证结果相一致,表明圆筒形部件变形评价模型、指标及方法准确可行、具有实用价值;样本数据量越多,指标计算结果越准确,但影响越小;不建议在圆筒形部件上焊接,以避免出现严重变形。     

基于MATLAB Robotics Toolbox的UR5机器人轨迹规划与仿真

为了解UR5机器人实时轨迹变化情况,根据Denavit-Hartenberg参数法在MATLAB Robotics Toolbox中利用Link函数建立了UR机器人的三维数学模型,对UR5机器人进行了正、逆运动学求解与理论分析,推导出各个关节角之间的变化关系;利用三次多项式插值法对任意PTP (点到点)之间的空间轨迹规划进行理论分析,并结合MATLAB Robotics工具箱对UR5机器人数学模型进行了空间轨迹规划和仿真,得到了连续变化的轨迹曲线。仿真结果验证了机器人运动学模型的正确性和合理性,为UR系列机器人的进一步研究和应用提供了理论依据。     

花键轴断裂原因分析

通过对断裂花键轴断口的宏微观形貌、材料化学成分、金相显微组织、硬度及形状尺寸进行了测试与分析,并应用理论计算和有限元模拟分析,确定了花键轴的断裂性质及断裂原因。结果表明：该花键轴的断裂性质为扭转疲劳断裂,花键轴发生扭转疲劳断裂可能与共振有关;另外,花键轴花键与机匣内花键啮合间隙不当和断裂处轴径尺寸偏小均为促进其扭转疲劳断裂的影响因素。     

Experimental calibration of density-dependent modified Drucker-Prager/Cap model using an instrumented cubic die for powder compact

Theory and experimental calibration of density dependent modified Drucker-Prager/Cap (DPC) model are presented by using a novel instrumented cubic die in powder compaction tests. The cubic die is designed for directly determining the loading and unloading forces and displacements of powder compact inside the die in compaction and transverse directions without any additional calibration. The cap surface parameters and elastic properties are characterized by fitting stress and strain curves recorded during loading and unloading at different green density values and the plastic material parameters for failure surface are obtained by additional radial and axial compressive tests. The experimental data is subsequently used in the simulation of cubic die compaction to verify the results from the density dependent modified DPC model.