金属切削中如何选择切削液

概述了切削液的种类和性能,介绍了目前切削液的使用情况,重点探讨了在不同的材料、不同的切削方法、各种常见刀具及良好的经济效益下选择切削液的基本原则.     

动态切削力对切削颤振的影响

以外圆车削实验为依据,建立加工过程中刀具振动的非线性动力学模型,并采用数值分析方法,研究切削力中的动态分量对切削颤振的影响.结果表明,随速度变化的切削力分量对颤振幅值影响较小,而且会在短时间内被系统内的结构阻尼所衰减.而与加速度成非线性关系的切削力分量对颤振的影响却很显著,而且加速度系数有临界值存在,当超过这个临界值后,颤振的理论幅度将急剧增大.     

干切削的刀具和切削条件选择

介绍适用于干切削的刀具设计和切削加工参数的选择。     

Wear mechanisms of cutting tools in high-speed cutting processes

Contemporary cutting tools used for High Speed Cutting (HSC), made on the basis of micro-grained cemented carbides with multi-layer protective coating, allow for effective machining of hardened and tempered steels of hardness over 50 HRc. The characteristic wear of such tools is affected by the fact that the cutting speed is no longer the main influential factor on wear; the wear can also be the consequence of the high-speed tool movements in the feed direction. The paper presents some original research into the wear types, as well as the phenomena in the cutting zone and their relationships to the causes and main wear mechanisms (adhesion, abrasion and diffusion) for the tools used in HSC.     

高速切削中切削温度研究方法

切削热与切削温度的产生和影响是高速切削技术研究的重要内容。高速切削过程中的温度检测技术与研究方法是在传统切削速度加工相关技术基础上的发展与创新。归纳了高速切削中切削温度实验测定方法和数值计算方法,指出了各种方法的优缺点及适用性。     

高速切削过程测温方法综述

切削温度与加工精度和刀具磨损密切相关,高速切削过程中切削温度随着材料,刀具,切削用量的选择不同而呈现出与普通切削过程不同的变化规律.本文归纳了高速切削当中切削温度的测定方法,并指出了各种方法的优缺点及适用性.     

超声处理乳化液在金属切削中的应用

为了减少机械加工中乳化液的使用量,达到节能减排的目的,对乳化液进行了超声波处理,并用它做切削液进行了正交切削试验,研究了乳化液流量、处理时间、水质、乳化液浓度等参数对主切削力的影响,给出了正交试验优化后的各因素取值为:流量2.0L/min,处理时间1.5h/L,水质用自来水,浓度10%.     

一种等离子切割机切割机构的设计

针对等离子切割在不锈钢板材下料方面的应用讨论,通过对目前下料方式的优缺点分析,阐述了等离子切割在该领域应用的重大意义,设计出了一种等离子切割机的整体结构方案,详细说明了切割工艺过程。同时,对机器切割机构部分进行了深入的探讨,通过对该机构的功能和运动分析、对各种实现方案的比较以及对关键部件的设计计算,提出了一种经济适用的结构方案。该切割机构结构简单,调整方便,能较好地满足切割生产要求。     

Thermofrictional pipe cutting

Russian Engineering Research -     

一种用于半干切削的微量冷却润滑系统

在金属切削过程中,大量使用冷却润滑液很难满足人们对环保的要求。因此,干切削、半干切削就成为当前金属切削研究中的一个热点。在很多情况下,完全干切削几乎是不可能的,那么如何在最少冷却润滑液用量的情况下满足切削要求呢?德国bielomatik Leuze公司(www.bielomatik.com)在EMO2001展出了专门满足这一要求的微量润滑系统,适用于刀具的内部和外部润滑。     

The optimal cutting times of multipass abrasive water jet cutting

Cutting is one of the most important applications of abrasive water jet. However, there are always some quality defects in the cross section cut by abrasive water jet. It is found that multipass abrasive water jet cutting can effectively improve the cutting quality. In this paper, two types of multipass water jet cutting were summarized and redefined clearly first. Then, taking AISI 304 stainless steel as the workpiece, the cross sections after cutting with different cutting times were analyzed and compared with that after single cutting. The overall roughness and the overall taper of the section were obtained by a reasonable method. Besides, in order to give consideration to both the cutting quality and the processing time, the concept of quality improvement rate was put forward. On this basis, with the improvement rate as the index, the optimal cutting times for cutting AISI 304 stainless steel with multipass abrasive water jet were analyzed from two aspects of surface quality and kerf taper, and the optimal cutting times of cutting other materials by multipass abrasive water jet can be studied according to the same idea. The study of this paper provides important reference for the application of multipass abrasive water jet cutting.     

Modeling of the minimum cutting thickness in micro cutting with consideration of the friction around the cutting zone

Friction modeling between the tool and the workpiece plays an important role in predicting the minimum cutting thickness during TC4 micro machining and finite element method (FEM) cutting simulation. In this study, a new three-region friction modeling is proposed to illustrate the material flow mechanism around the friction zone in micro cutting; estimate the stress distributions on the rake, edge, and clearance faces of the tool; and predict the stagnation point location and the minimum cutting thickness. The friction modeling is established by determining the distribution of normal and shear stress. Then, it is applied to calculate the stagnation point location on the edge face and predict the minimum cutting thickness. The stagnation point and the minimum cutting thickness are also observed and illustrated in the FEM simulation. Micro cutting experiments are conducted to validate the accuracy of the friction and the minimum cutting thickness modeling. Comparison results show that the proposed friction model illustrates the relationship between the normal and sheer stress on the tool surface, thereby validating the modeling method of the minimum cutting thickness in micro cutting.     

Modeling and experimental verification of cutting forces in gear tooth cutting

Due to complex cutting edge profile of an involute cutter, calculations of chip width and consequently cutting force are quite problematical. This article presents a mechanistic approach in the prediction of cutting force components arising in the course of gear tooth cutting by an involute form cutter. To permit calculation of chip width (and so cutting forces), a discrete model is utilized and cutting force components are then derived using Kienzle approach. Moreover, several experiments are performed under different cutting conditions to prove the effectiveness and accuracy of the used method. The results have revealed that cutting force components can be predicted in form gear tooth cutting with a significant accuracy.     

基于切削力的刀具故障诊断

提出和实现了一种基于切削力状态参量判别刀具故障的方法。利用LabVIEW软件平台采集和分析切削力信号。调用MatLAB中的小波包工具将信号分解,并计算各频段的能量谱,输入BP神经网络进行训练。将经过训练后的BP网络用于对刀具故障进行诊断,并给出了应用实例。     

采用接刀方法线切割加工大长度齿条刀具

线切割加工是制造齿条刀具的关键工序 ,齿条刀具的全部齿形参数———齿距、齿厚、全齿高、螺旋角、后角、齿形角等均通过该工序一次成形。由于我厂所用ＣＨＡＲＭＩＬＬＥＳ 2 90型线切割机床的行程限制 ,只能加工长度≤ 35 0ｍｍ的齿条刀具 ,而用户订货的齿条刀具最大长度达 4 80ｍｍ ,为了利用现有设备加工出超行程的大长度齿条刀具 ,只能采用接刀方法进行加工。接刀加工是将一把齿条刀具分为两段分别加工。线切割机床的上、下喷嘴是按程序编制的加工轨迹移动 ,喷嘴周围有较大空间 ,因此可根据程序的加工方向将齿条刀具的一端固定在加工…