Electrical discharge dressing of honing stones

Honing processes require a systematic preparation and a regeneration of the honing tool to guarantee a sufficient cutting behaviour and prevent unintended wear of the tool. These dressing processes are particularly important for the regeneration of the macro- and microscopic topography of the honing stones. The established method of manual shaping subsequent to a cylindrical grinding process demands a high skill level, a great amount of non-productive time and is not reproducible.In this paper the preparation of honing stones by use of electrical discharge machining (EDM) is presented. The aim is to ensure an automatic, systematic and reproducible process of resetting the bond of honing stones. Different tool electrode materials were analysed systematically for two different bond specifications of the honing stones. EDM process parameters were studied within a design of experiments (DoE) strategy and a subsequent effect analysis to assure the identification of most appropriate EDM process parameters. After this procedure various cycles of long-stroke honing processes were carried out. As a result, the new approach makes it possible to prepare honing stones with reproducible sharpness and macroscopic topography within an automated process. The dressing time t_d was reduced by 88 % compared to the established method.     

缸套珩磨网纹模拟及流动特性分析

目的 研究缸套珩磨网纹表面计算机模拟方法,对比缸套网纹表面确定性分析流量因子与Patir & Cheng高斯分布流量因子差异。方法 采用快速傅里叶变换技术(FFT)及坐标变换,对高斯分布平台表面及具有任意方向的各向异性沟槽表面进行了计算机模拟,并叠加合成满足要求Rpq、Rvq及珩磨角度参数的双高斯缸套珩磨网纹表面。通过表面概率支承率曲线分析,验证该方法的精度。在此基础上,进行给定边界条件下网纹表面的流动分析,对比确定性分析流量因子与Patir & Cheng高斯分布流量因子差异。结果 调整表面高度标准差、珩磨角度及自相关长度,可实现不同参数珩磨网纹的建模,生成的珩磨网纹表面参数与给定输入参数偏差较小。相比Patir & Cheng高斯分布流量因子,珩磨网纹确定性分析压力流量因子能更好地反映珩磨角度对不同方向流量的影响。同时,珩磨网纹沟槽对小间隙下剪切流量的影响更加明显。结论 网纹表面的确定性分析流量因子与Patir & Cheng高斯分布流量因子存在较大差异,缸套网纹表面建模及流动特性分析可更好地反映表面粗糙度对表面润滑性能的影响,为进一步开展缸套-活塞环多尺度摩擦学分析及珩磨网纹参数优化奠定了基础。     

Non-Resonant Structure Design of Catenary Transformer in Ultrasonic Gear Honing

To solve the design problem of transformer composed of non-resonant structure in ultrasonic gear-honing,force coupling conditions for moderately thick annular plate (MTAP) and catenary horn are propose...     

基于缸孔珩磨表面微观特征的质量检测模式与提升监控水平的探索

分析了缸孔珩磨表面微观构造对汽车发动机性能产生极大影响的原因,指出对珩磨表面平台网纹形貌进行质量检测的重要性。强调了随着机动车节能和减排法律法规的日趋严苛,企业在质量监控方面也应持续完善提高,并对近年来在该领域的技术进展进行了介绍。     

超声珩齿加工工件对谐振频率影响的研究

将超声珩齿加工变幅杆和被加工齿轮组成的超声振动系统简化为变幅器,基于圆锥形变幅杆和环盘(被加工齿轮)组成变幅器的频率方程,导出齿轮半径、厚度变化对谐振频率的影响,以及变幅杆的调整规律,并运用有限元分析的方法对设计结果进行了验证,从而为变幅杆及工作频率的设计选择提供了依据。     

珩磨工具用中温钎焊材料的研制

针对目前珩磨条钎焊存在的问题,采用中温钎焊对珩磨工具进行了连接试验,对中温钎焊用钎料的化学成分进行了调整,测试了钎料的熔化温度、钎料对珩磨条的润湿性以及钎焊接头的抗拉强度,并比较了不同钎料钎焊后珩磨工具的变形量.研究表明:中温钎焊工艺变形小,强度较高,是珩磨条连接的可行方式.     

珩齿切削速度分布特性对齿面质量的影响

珩齿加工过程中接触线上切削速度分布的不同会导致齿轮工件经珩齿后齿廓表面质量差异较大,影响工件的使用性能,为了进一步提高硬珩齿加工质量,根据运动展成原理并结合坐标变换法推导出了接触点上的切削速度的向量表达式,通过实验得出切削速度与齿轮工件齿面质量之间的关系。实验结果表明,随着珩齿速度的提高,工件同一齿面粗糙度值的差异会进一步扩大,同一齿齿面质量差异会更加明显。     

Effects of honing treatment on AIP-TiN and TiAlN coated end-mill for high speed machining

The objective of this work is to compare the tool performance of TiN and TiAlN coated carbides end-mills deposited by an arc ion plating (AIP) method, using honing treatment to polish the cutting edge surface sleekly. The curve of surface roughness versus honing time showed a rapid improvement initially and thereafter became steady, manifesting a saturation effect. The optimal honing time related to surface roughness was determined to be approximately 20 s. As the surface roughness increased, the critical loads reduced. At an average surface roughness (Ra) of 0.028 μm, the highest critical loads of TiN and TiAlN coating layers were 98 and 114 N, respectively. Tool performances of uncoated and coated tools were conducted under high speed machining (HSM) of AISI D2 cold-worked die steel (62 HRC). Consequently, the TiAlN coated end-mill using honing treatment showed excellent tool life under HSM conditions.     

发动机缸孔珩磨网纹评定及常见网纹问题解析

介绍了缸孔珩磨表面品质评定的理论基础,阐述了各个评定参数和发动机性能之间的关系,同时对每个网纹参数超差的原因,进行了理论性分析和总结,并列举和分析了生产中缸孔珩磨网纹参数不符合要求的常见问题。     

发动机缸孔平台珩磨加工技术初探

发动机缸套工作表面的质量对发动机的工作性能、使用寿命以及经济性能有着重要的的影响．发动机缸孔平台网纹珩磨技术就是保证缸孔表面质量的重要手段,论文简要介绍平台网纹珩磨加工技术的优势、加工原理、评价方法及关键技术参数,并将其应用到V6、4GB发动机缸套实际加工．取得了很好的效果。