钢球制造工艺(5)

第六章 锉削与光球 一、加工原理及加工规范 1.锉削加工 将有环带的冷镦球坯或除去环带后的热镦球坯放在两块带有锉齿的锉盘之间加工,称锉削,如图6-1所示。锉削时,下锉盘转动,上锉盘不转动;球坯一方面受到下锉盘旋转离心力的作用,向外径方向移动,另一方面在工作压力P以及下锉盘的转动作用下,既滚动又作微量自转,从而使其表面反复受到锉齿的挤压和锉削。锉削过程大致如下:首先,在球坯表面上挤压出错综复杂的锉齿牙痕,接     

凸凹骑缝孔零件钳工锉削加工方案研究

以一个典型的凸凹骑缝孔零件锉削复杂加工为例,分析其加工工艺特征,制定加工工艺过程,充分利用基准互换,准确测量工件尺寸精度,按技术要求完成零件的加工,旨在探讨以孔为检测和加工基准的零件的锉削方法和技巧,充分利用百分表、量块、正弦规等量具进行科学测量,使锉削精度达到更高的层次。     

超声振动锉削加工C_f/SiC复合材料试验研究

碳纤维增强碳化硅陶瓷基(Cf/Si C)复合材料是一种应用普遍的纤维增强陶瓷基复合材料。针对Cf/Si C复合材料复杂曲面难加工问题提出了超声振动锉削加工方法,建立数学模型分析其加工机理,设计可行性试验验证表明超声振动锉削相对于传统锉削加工方法,可以降低锉削力,提高加工表面质量。利用单因素试验研究了刀具粒度、超声功率、径向锉削深度及水平进给速度对锉削力和被加工件表面粗糙度的影响。结果表明:锉削力随超声振动功率的增大而减小,随锉削深度和进给速度的增加而增大,与理论模型推导结论吻合;超声振动功率的增加可以提高工件表面质量,而锉削深度和进给速度的增加则会降低表面质量。     

平面锉削姿势教法创新

在现代工业生产的条件下,仍有一些不便于机械加工或条件不允许的零件,需要用手工锉削加工。例如：装配过程中对个别零件的修整、修理,小批量生产条件下某些复杂形状的零件加工,以及样板、模具加工等,所以锉削仍是钳工的一项重要的基本操作。作为锉削的人门技能—平面锉削姿势,是锉削操作的基础技能。平面锉削姿势正确与否,     

电解锉削研磨装置

该装置利用电解锉削与电解研磨的原理,用于钳工锉削与研磨硬质合金、淬火钢、模具钢、不锈钢等难以加工材料,去除率为0.04～0.05mm/mm~2·min,表面粗糙度可达Ra0.8。该装置的操作方法符合钳工锉削研磨的     

加工软金属的锉刀

用普通锉刀加工紫铜、铝等软材料时,往往会因锉刀积屑而破坏工件表面,使锉刀失去锉削能力。为了适应铜件和铝件的加工需要,     

钳工挫削工艺问题研究

锉削是钳工的一项重要的基本操作,主要考核钳工控制尺寸、形位公差等技能。从加工工艺角度探讨如何提高工件的锉削质量。首先探讨了锉削工艺的重要性,然后从钳工锉削过程中主要存在的问题及原因论述了钳工锉削工艺制定的基本方法。     

浅析钳工锉削面不平现象的原因与预防措施

锉削是操作者用锉刀把零部件表面多余的金属给处理掉,使零件达到图纸上要求的尺寸、形状及各表面粗糙度的操作方法。这一操作技术在一定程度上反映了钳工操作技能水平的高低,本文就钳工锉削技能操作中,对锉削面不平现象的原因进行了理论分析,并提出了几种预防锉削平面不平的措施。     

锉削操作技法

根据笔者多年的锉削加工实践和实训教学经验 ,对锉削操作方法及其应用范围进行了系统总结。本文对锉削操作方法中的基本锉法、平面锉法和曲面锉法作一介绍。　　1　基本锉法(1)粗加工锉削 (粗锉 ) :当加工余量大于 0 5ｍｍ时 ,一般选用 30 0ｍｍ、35 0ｍｍ的粗齿、中齿锉刀进行大切削量加工 ,以去除工件余量较多部分。(2 )细加工锉削 (细锉 ) :当加工余量介于 0 5～0 1ｍｍ时 ,一般选用 2 5 0ｍｍ、30 0ｍｍ的细齿锉刀进行小切削量加工 ,以接近工件的要求尺寸。(3)精加工锉削 (精锉 ) :当加工余量小于 0 1ｍｍ时 ,一般选用 2 0 0ｍｍ、2…     

加工软金属的锉刀

用普通锉刀加工紫铜、铝等软材料时,往往会因锉刀积屑而破坏工件表面,使锉刀失去锉削能力。为了适应铜件和铝件的加工需要,我厂制造并使用了一种单纹锉刀(附图1、2)。经生产实践证明,效果很好。该锉刀的特点为: (1)锉齿如同刨     

对钳工锉削面不平现象的探讨

本文就钳工锉销技能操作中，对锉削面不平面的现象的原因，从操作资势，锉削用车，锉削速度，锉削方法等方面进行了理论分析，并指出了锉削方法，速度，压力等选择对锉削平面质量的影响。     

激光焦点自动跟踪系统

在激光切割中,激光聚焦头必须实时跟随工件表面的随机误差,使焦点始终落在工件上。本文根据激光切割的特性和要求,提出用电容传感器检测、由单片机控制的激光焦点非接触式自动跟踪系统,应用于国家“七五”攻关项目——大型数控五坐标联动激光切割划线机上,获得满意的效果.     

Workpiece Surface Integrity and Tool Life Issues When Turning Inconel 718™ Nickel Based Superalloy

Inconel 718 is one of a family of nickel-based superalloys which are used extensively in the aerospace industry in the hot sections of gas turbine engines. The literature detailing the effects of varying operating parameters on tool life when machining nickel based superalloys is comprehensive, however, relatively little of this data refers to their effects on machined workpiece surface integrity. Greater knowledge of the effects of operating parameters on surface integrity is critical to the acceptance of new cutting tool materials, tool geometries, and strategies, especially by the aerospace industry. The article initially reviews prior work on the machinability and surface integrity achieved when turning Inconel 718. Following on from this a series of experiments evaluating the effects of varying cutting tool material, geometry, and operating parameters are detailed.     

Evaluation of machinability according to the changes in machine tools and cooling lubrication environments and optimization of cutting conditions using Taguchi method

This study analyze the effect of machine tools, cooling lubrication environments and cutting conditions on surface roughness and cutting force, and propose the combination of cutting conditions which minimizes the effect of machine tool variables on the dispersion of cutting force and surface roughness by treating the changes in machine tool itself and the installation environments as a noise factors. To do so, the Taguchi method is used to establish an experiment plan, and flat end milling is carried out to measure cutting force and surface roughness. The research results show that in the case of cutting force, the effect of cutting conditions is dominant, and changes in machine tools and cooling lubrication environments barely have effect on cutting force. However, in the case of surface roughness, all of the cutting conditions, machine tool and cooling lubrication environment variables have impact. In order to select a combination of cutting conditions insensible to changes in machine tools, considerations for feed per revolution and axial depth of cut turn out most important in the aspect of cutting force, and considerations for feed per revolution is most important in the surface roughness.     

一种多功能新型画规及其在容器制造中的应用

目前的板样方法普遍采用普通画规近似作图法进行划线板样,此种方法存在着一定的理论误差,且操作繁琐,效率低。针对这一情况,设计了一种新式多功能画规,此画规在具有普通画规功能的基础之上,可有效地解决上述问题。文中对此种多功能画规的结构、原理及其在容器制造中的应用进行了介绍,并将其与普通板样方法进行了比较。     

EFFECT OF CRYSTALLOGRAPHIC ORIENTATION ON CUTTING FORCES AND SURFACE FINISH IN DUCTILE CUTTING OF KDP CRYSTALS

In order to investigate the influence of material anisotropy in ductile cutting of Potassium Dihydrogen Phosphate (KDP) crystals, experiments of face cutting of (001) plane of KDP crystals are carried out by using an ultra-precision lathe with a single point diamond tool. The cutting forces, surface finish, and surface roughness in all crystallographic orientations of the machined surface are measured, and a power spectrum analysis method is used to reveal the cutting force patterns. The experimental results show that the cutting forces and surface roughness vary greatly with different crystallographic orientations of KDP crystal, and that amplitude variation of cutting forces and surface finish is closely related with the cutting parameter of the maximum undeformed chip thickness. With the maximum undeformed chip thickness below 30 nm, the amplitude variation of cutting force and surface finish is minimized, and a super-smooth surface with consistent surface finish in all the crystallographic orientations can be achieved. The surface roughness is 2.698 nm (Ra) measured by Atomic Force Microscope (AFM). These findings provide criteria for achieving a large-scale KDP crystal with consistent super-smooth surface using ductile cutting technology.     

硬切削表层残余应力特征预测研究

结合精密硬切削加工表层残余应力曲线的勺形分布特征,提出了以表面应力值、最大应力值、最大深度值和有效深度值4个变量作为表达残余应力曲线的特征参数,并作为BP网络的输出量,以刀具几何参数和切削参数等影响硬切削加工最为显著的变量为输入量,建立了硬切削加工表层残余应力特征BP网络预测模型。最后,通过实验验证了模型的准确性,实现了对精密硬切削加工表面残余应力较高精度的预测。     

高精刀剪专用数控磨床设计

为提高刀剪的表面质量及形位精度,设计一款刀剪专用数控磨床。该款磨床包括3种机型,都是由980T数控系统及机械两部分组成。主要针对数控指令的二次开发,主轴的径、轴向间隙调整,进给消隙及机床润滑等技术关键点进行重点研究。该产品经国内多家生产刀剪的企业使用,磨刀效果为:刀剪的表面粗糙度达到Ra0.4～Ra0.2,且刀刃口厚薄均匀,刀圆弧外表面美观,刀纹路细腻,不留刀痕,剪刀工作上下刃口在工作长度内始终保持圆弧线相切的点接触,刃口锋利耐用。磨头可在2 800～3 200 r/min高转速的条件下连续工作,达到了高效、高精度的目的。     

Cutting characteristics of porcine tenderloin tissue along tangential direction of surface

In some special surgeries, e.g., burnt necrotic tissue removing process and skin grafting process, the cutting edge of scalpel moves along the tangential direction of tissue surface to achieve the cutting of biological tissue. This cutting pattern, which is similar with the turning process of metal material, is essential different from the vertical cutting presented in literatures. As a first endeavor, the cutting characteristics along tangential direction of porcine tenderloin surface are investigated experimentally, where the bottom surface of tissue is fixed and the top surface is free. A set of advanced devices especially for ex vivo porcine tenderloin cutting, which can easily adjust the variable under different operating conditions, are designed and manufactured. The real-time device records quantitatively the cutting forces and tissue deformations, which is for evaluating the cutting energies and the fracture toughness, and analyzing the whole cutting process in detail. Additionally, a compression test device is designed for performing a standard component compression experiment, which is used to evaluate the tensile yield stress and the pain degree. A novel quantitative metric is proposed for predicting the pain degree (PDI) with a typical compression test. The relationship between the stress and the pain feeling is presented by the compression test of the particular sample.     

Comparative Analysis of Conventional and Non-Conventional Optimisation Techniques for CNC Turning Process

This paper describes various optimisation procedures for solving the CNC turning problem to find the optimum operating parameters such as cutting speed and feedrate. Total production time is considered as the objective function, subject to constraints such as cutting force, power, tool–chip interface temperature and surface roughness of the product. Conventional optimisation techniques such as the Nelder Mead simplex method and the boundary search procedure, and non-conventional techniques such as genetic algorithms and simulated annealing are employed in this work. An example is given to illustrate the working procedures for determining the optimum operating parameters. Results are compared and their performances are analysed.