外圆纵向智能磨削控制系统的研究

通过对磨削机理、专家系统、模糊神经网络和人机一体化学术思想的深入研究，本文提出了一种外圆磨削加工中人机一体化智能控制策略。其中，初始磨削加工参数由基于神经网络的专家系统决定；磨削过程中采用了大进给和超切人的优化磨削方法；由二个模糊神经网络和人组成的合作智能控制系统实时修正磨削加工参数。实验结果表明，该系统在外圆磨削加工中适应性强，可极大地提高磨削质量和效率。     

基于FNN智能型磨削参数决策系统

本文结合对磨削机理,模糊逻辑,神经网络的研究提出了一种基于ＦＮＮ的智能型磨削参数决策系统。在这个系统中,首先由上层专家系统决策出初始磨削参数,然后由两个ＦＮＮ单元对磨削参数进行修正。其中ＦＮＮ１利用磨削结果对磨削参数进行修正,ＦＮＮ２利用当前砂轮磨损状况对磨削参数进行修正。．     

磨削液的合理选择

本文论述磨削加或所产生的弊病,从而提出了对磨削液的特殊要求,才可得到一种比较理想的磨削液。     

磨削智能预测控制系统研究

建立了一种智能预测控制系统。该系统根据各磨削阶段的特点,在不同阶段分别采用不同的优化控制策略：粗磨阶段,采用在烧伤极限内大进给和变速磨削优化策略;精磨阶段,采用由神经网络预测、模糊逻辑控制的工件尺寸智能优化方法;光磨阶段,采用工件表面粗糙度模糊神经网络预测辨识控制方法。基于神经网络的专家系统,提供各阶段初始磨削加工参数。实验结果表明,该系统在外圆磨削加工中适应性强,可极大地提高磨削质量和效率。     

难磨削零件的高精度平面砂带磨削

薄片(δ?3mm)零件、有色金属及非金属零件的高精度平面磨削至今尚无一种简便易行的加工方法。本文针对这类零件的结构及工艺特点,分析了各种平面砂带磨削的工艺性能,并在此基础上提出了转台式压磨板平面砂带磨削方法及相应工艺装备,对这一工艺的特点及可行性作了较详细的分析,并进行了工艺试检。结果表明,该方法克服了常规砂轮磨削的不足,加工精度高,并可提高加工效率3倍以上(有色金属和非金属件效率更高),加工成本仅与铣削相当,加工表面质量好,表面密封效果特别好。为压缩机阀片、离合器的金属与非金属摩擦片、摩托车发动机箱体、液压阀体以及塑料、胶木、橡胶等非金属板件、垫片的高精度平面加工提供了一种经济有效的工艺方法。     

切入式磨削烧伤仿真预测与控制方法研究

基于磨削热传递模型和磨削去除率模型,提出了一种基于监控功率信号的切入式磨削烧伤仿真预测与控制方法,对砂轮在粗磨、半精磨、精磨、光磨各阶段的磨削功率信号进行监测,再利用计算机对机床数控系统各加工工艺参数进行控制,使砂轮实际磨削功率信号始终低于磨削烧伤最大功率边界的5%～15%,来避免出现工件磨削烧伤现象;同时,用轴承套圈内圆磨削试验验证了该方法的有效性和实用性。      

生物组织磨削加工研究

生物组织的磨削加工本质上是通过细小磨粒对软硬组织进行少量多次去除，保证操作的精细度和安全性。磨削加工是一种能量密集型的加工方式，加工过程中会产生较高的磨削热和磨削力并直接作用于人体，有可能造成周围组织损伤，影响手术效果。介绍了骨组织磨削、皮肤磨削、齿科磨削和血管钙化组织磨削等生物组织的固结磨料加工的研究情况，并提出后期研究主要方向。      

立轴平面磨削方式对磨削效果的影响

分析比较了垂直磨削、倾斜磨削和逆倾斜磨削三种方式下的磨削比、功率消耗和砂瓦磨损等指标。提出了合理选择立轴平面磨削方式的依据,以利于提高磨削效率,降低砂瓦磨损。     

ELID磨削加工参数专家系统的开发

介绍了作者开发的ELID磨削加工参数专家系统。本软件利用Visual Basic进行界面设计,以Ac-cess实现数据库的管理和维护,以混合推理为原则建立专家系统。用户可以输入被加工材料机械加工性能参数和预期加工精度值要求,推测出针对该种材料的ELID磨削工艺参数和电解参数的可选范围。该系统对优化ELID磨削工艺过程、降低加工成本、提高加工效率等方面有实用价值。     

钢结硬质合金的超精密磨削

本文提出了一种用机械化学磨削实现钢结硬质合金ＧＴ３５超精密磨削的方法，研究了机械化学磨削机理。研制出一种适合于ＧＴ３５超精磨密削用的磨削液，用这种磨削液要吧实现用带有石墨填充的树脂结合剂刚石砂轮进行超精密磨削硬质材料ＧＴ３５。磨削后表面粗糙度Ｒａ，Ｒｚ值低（Ｒａ＝０．０１７μｍ，Ｒｚ＝０．０８５μｍ），表面质量好。本文比较了用不同磨削液冷却时磨削后的表质量，确定了新研制磨削液的磨削效果。同时还研究     

Simulation based optimization of the NC-shape grinding process with toroid grinding wheels

For achieving high material removal rates while grinding free formed surfaces, shape grinding with toroid grinding wheels is favored. The material removal is carried out line by line. The contact area between grinding wheel and workpiece is therefore complex and varying. Without detailed knowledge about the contact area, which is influenced by many factors, the shape grinding process can only be performed sub-optimally. To improve this flexible production process and in order to ensure a suitable process strategy a simulation-tool is being developed. The simulation comprises a geometric-kinematic process simulation and a finite elements simulation. This paper presents basic parts of the investigation, modelling and simulation of the NC-shape grinding process with toroid grinding wheels.     

Basics for In-Process Roundness Error Improvement by a Functional Workrest Blade

A centerless plunge feed grinding process can be conducted “below center” in order to increase process productivity. This statement results from the fact that the workpiece, in such a set up of the grinding gap, is fixed between grinding wheel, control wheel and workpiece rest blade, thus allowing higher feed rates of the grinding wheel support. But when grinding “below center”, the advantage of a higher productivity is accompanied by a negative effect, the arise of a polygonal workpiece form. Regarding only the geometrical rounding effect as one reason for this process characteristic phenomenon, different workpiece center displacements are examined and analytically described. The knowledge of relevant workpiece center movements within a centerless grinding application allows a quantified analysis of the influence of these displacements on the geometrical rounding effect. Deriving from such an analysis, a functional workrest blade is discussed, which influences the stability of the geometrical rounding effect.     

Dressing process model for vitrified bonded grinding wheels

A holistic dressing process model for vitrified bonded grinding wheels was designed. It regards the dressing process as a tribological system subjected to a complex load collective. The intensive analysis of the input variables and their impact on the system function led to new knowledge about the acting mechanisms. The model enables a qualitative prognosis of the grinding wheel topography, the dressing forces and the thermal dressing process load.     

安全阀关闭件研磨修复粗糙度预测与实验研究

目的优化安全阀关闭件研磨工艺参数,提高安全阀密封面研磨质量。方法采用Al2O3砂纸为磨具,通过正交试验研究了磨粒细度、研磨时间、研磨转速、研磨压力对阀座和阀瓣表面粗糙度的影响规律。采用粗糙度测量仪对阀座和阀瓣的表面粗糙度进行检测,初步获得了较好的研磨工艺参数。采用MATLAB中BP神经网络解决非线性映射逼近问题,建立表面粗糙度预测模型,分析安全阀研磨工艺实验得来的16组真实样本数据,并对不同工艺参数下的粗糙度进行预测。结果通过正交试验可以初步获得较好的研磨工艺参数,分别是:磨粒细度1500目、研磨压力100 N、研磨转速100 r/min、研磨时间10 min。进一步设计更全面的正交试验,验证粗糙度模型的预测结果,得到最好的研磨方案是:砂纸细度1500目、研磨压力120 N、研磨转速80 r/min、研磨时间12 min。结论粗糙度预测模型能够很好地预测表面粗糙度,并得到最佳工艺参数,表面粗糙度可以降低到0.074μm,有效地提高了研磨质量。     

Numerical and physical simulation of new SPD method combining extrusion and equal channel angular pressing for AZ31 magnesium alloy

A new serve plastic deformation(SPD) including initial forward extrusion and subsequent shearing process(ES) was proposed.The influence of the ES forming on the grain refinement of the microstructure was researched.The components of ES forming die were manufactured and installed to Gleeble1500D thermo-mechanical simulator.The microstructure observations were carried out on the as-extruded rods(as-received) and ES formed rods.From the simulation results,ES forming can increase the cumulative strain enormousl...     

航空轴承内圈滚道磨削残余应力的工艺优化及试验研究

对国内外8Cr4Mo4V钢制航空轴承套圈滚道磨削残余应力进行了对比试验,根据航空轴承内套圈滚道磨削工艺特点,基于ABAQUS建立轴承内套圈滚道磨削残余应力的有限元分析模型并进行了数值计算,对内套圈滚道的残余应力进行了检测、分析及验证,进而优化了轴承内套圈滚道磨削工艺。结果表明：通过增加喷丸工序、适当提高进给速度和终磨采用220目白刚玉砂轮替代石墨砂轮可有效提高轴承内圈滚道残余压应力。     

新型镁合金大变形技术的研究与验证

研究了一种正挤压与等通道挤压相结合的新的Extrusion-Shearing(ES)变形方法。应用有限元法对ES变形过程进行了计算机模拟,表明ES技术可以大大提高累积应变和动态再结晶晶粒的体积分数。在Gleeble1500热模拟机上安装ES成形模具,对ES成形挤出的棒料进行微观组织观察,并对热模拟的数据进行处理。结果表明,ES成形可以细化晶粒并提高成形的均匀性。计算机模拟和热模拟实验表明,ES成形是一种新型的镁合金大塑性变形方法,可以有效细化晶粒、提高组织的均匀性     

GCr15钢的ELID磨削性能实验研究

为了探讨GCr15钢的ELID（Electrolytic In-process Dressing）磨削性能，在基于大量实验的基础上，对GCr15钢采用ELID磨削时磨削力的变化规律进行了详细分析，并将磨削力、磨削表面粗糙度与普通磨削进行了比较。结果表明，采用铸铁结合剂CBN砂轮进行ELID磨削时磨削力几乎不随时间的变化而变化，而采用白刚玉砂轮进行磨削时的磨削力随时间的变化不断增大，在线电解修整使CBN砂轮在磨削过程中始终保持良好的磨削性能，有利于节省砂轮修整时间，提高加工效率。在ELID磨削中，采用微细砂轮进行磨削可以获得很低的表面粗糙度，实现对GCr15钢的超精密镜面磨削。     

Determination of waviness decrease rate by measuring the frequency characteristics of the grinding force in centerless grinding

In centerless grinding, it is difficult to optimize the grinding conditions for minimizing the workpiece roundness error because of the high number of process parameters such as center height angle, blade angle, and stock removal rate. We had previously proposed a function for evaluating grinding conditions, i.e., the waviness decrease rate, in order to automatically select the optimum process parameters. In order to build a closed-loop control system for the process parameters, however, it is necessary to find a practical way to determine the waviness decrease rate. In this paper, the relationship between the waviness decrease rate and the dynamic components of the grinding force was investigated analytically. It was found that the frequency characteristics of the waviness decrease rate show a similar tendency to those of the grinding force. A grinding force measurement system was built and experiments for measuring the frequency characteristics of the grinding force were carried out. As a result, it was confirmed that the waviness decrease rate can be determined by measuring the frequency characteristics of the grinding force.     

基于UG的叶片数控砂带磨削刀位数据的计算

介绍了一种在UG环境下使用Open API编程计算叶片砂带磨削刀位点的方法,并开发了磨削加工仿真模块,对计算结果进行了仿真验证。该方法可省略编程建模的复杂过程,计算结果精度高,为叶片数控砂带磨削的后置处理奠定了基础。