基于华中数控系统宏程序的凸轮轴数控加工

云南省第四届数控大赛实操试题中有一种凸轮轴的零件,主要构成要素包括椭圆面、双曲面、阿基米德螺旋面、圆锥面、圆环面以及半球面等,利用自动编程软件编程,造型复杂、费时,生成的程序长,优化困难,不易检查、修改.在分析零件图纸和相关计算的基础上,利用华中世纪星HNC-21M数控系统提供的宏程序功能,快速、便捷地完成了加工编程,...     

HBF-01液数控制专用车床的设计

HBF-01液数控制专用车床具有液压控制机床的高效及大切削力,又具有数控机床的加工高精度和可进行多工序加工的优点。主轴结合齿轮变速与变频器调节,可自动调速,夹紧系统油压可自动二次调压。这些特点使得该机床可实现粗、精加工工序集中完成,达到批量生产的高质高效。     

热压罐成型复合材料构件的变形预测与应用研究

综述了热压罐成型复合材料变形的种类、具体影响因素、各种预测变形方法、研究的典型构件类型、变形预测应用的现状,最后对进一步研究变形预测及应用的方向进行了展望。     

基于振动信号的冷挤压内螺纹加工状态研究

研究了内螺纹冷挤压加工过程不同加工状态下的丝锥振动信号,分析了产生这些变化的原因,以深入研究振动信号变化规律与挤压丝锥磨损状态之间的关系,为内螺纹冷挤压工艺参数的进一步优化提供依据。试验分析结果表明,在不同加工状态下,振动信号变化趋势相同,信号频率主要分布在100Hz-1000Hz之间,主频分布稳定,丝锥的磨损只影响到各主频的幅值。在正常加工条件下,振动情况随着丝锥的磨损而加剧;出现加工异常情况,丝锥振动情况有所减缓。     

Fundamental investigations on the material flow at combined sheet and bulk metal forming processes

The class of combined sheet and bulk metal forming (SBMF) processes denotes the forming of sheet metals with typical bulk forming operations. As a consequence, simultaneous 2D and 3D stress and strain states are present. Furthermore the local shape elements formed out of the sheet plane are in the magnitude of the sheet thickness. This paper deals with process combinations upsetting/lateral extrusion and deep drawing/upsetting. It has been shown that an insufficient mould filling is nearly inevitable using conventional tooling systems. Hence, the prospect of newly developed forming approaches will be discussed.     

Hot deformation behaviour of 7075 alloy

The hot deformation behaviour of Stir cast 7075 alloy was studied using processing map technique. The map has been interpreted in terms of the microstructural processes occurring in situ with deformation, based on the values of a dimensionless parameter η which is an efficiency index of energy dissipation through microstructural processes. An instability criterion has also been applied to demarcate the flow instability regions in the processing map using another parameter (ξ). Both the parameters (η and ξ) were computed from the experimental data generated by compression tests conducted at various temperatures and strain rate combinations over the hot working range (300-500 °C and 0.001-1.0 s⁻¹) of the present material. The processing map exhibits one distinct η domains without any unstable flow conditions under the investigated temperature and strain rate conditions. The dynamic recrystallization zone and instable zones, i.e. adiabatic shear band formation, interface crack, and wedge cracking, were identified in the processing map. Microstructural examination was performed for validation. The processing maps can be used to select optimum strain rates and temperatures for effective hot deformation of 7075 alloy.     

基于Hadoop的分布式视频车辆检索方法*

针对传统单机视频检索效率低下的问题,设计了一种基于Hadoop的分布式视频车辆检索方法。该方法首先将视频切割成多个分块,然后利用MapReduce和FFMPEG在分布式环境下提取视频帧,再通过车牌识别算法检索其中出现的车牌号码,最后计算出车辆在视频中出现的时间。实验结果表明,与单机检索方式相比,该方式具有更强的数据处理能力和更高的检索效率。     

一种基于指令域示波器的数控加工工艺参数优化方法

针对当前国内外数控加工工艺参数优化只能离线操作的问题,进行了基于华中数控8型高档数控系统二次开发,完成了一套实时采集的指令域示波器模块,实现机床数据挖掘、分析、工艺参数优化等功能与数控系统的集成,完成机床加工状态心电图实时监测。通过指令域分析加工负载电流优化进给速率,可以大大提高加工效率。该方法操作方便,已经在航空航天复杂零件加工等领域得到了验证应用,加工效率提高了30%~40%。     

Advances in macro-scale laser processing

Laser material processing is a technology with an increasing number of industrial applications, especially for aviation and automotive. The present keynote paper focusses on the advances in macro-scale laser processing, meaning that the laser generated structures are large enough to be visible with the naked eye. Next to that, also the reasons for the advances, especially the improvements regarding the power and the beam quality of the laser sources, the higher capabilities of the systems technologies and an increasing process understanding are shown. Nevertheless, challenges like a holistic understanding of the physical phenomena and the evolution of defects in some processing methods remain to be solved in future.     

注射压缩工艺参数对厚壁塑件成形质量的影响

为探究注射压缩工艺参数对厚壁塑件成形质量影响,以表面缩痕指数为指标,选择注射压缩工艺中的熔体温度、模具温度、压力机打开距离、等待时间、压缩时间、压缩力和压机速度7个工艺参数作为分析因素,运用Moldflow软件进行正交实验,得到各工艺参数对指标的影响程度;然后对前5个主要参数作单因素实验研究,获得各参数对塑件表面缩痕指数、翘曲变形及体积收缩率等指标的影响趋势,并结合实际对该厚壁模型的成形工艺参数进行了合理的优化,使各指标值大大降低。