嵌入合金薄膜传感器的刀具结构优化与测力灵敏度分析

提出一种嵌入刀具的合金薄膜传应变感器切削力测量系统的模型,以提高系统的测量灵敏度为目的 ,将弹性元件刀柄作为研究对象,结合薄膜传感器受力变形与刀具强度理论,通过在刀柄合适位置加工凹槽、多层台阶槽与钻孔方式设计了多种刀柄结构.构建了含有矩形、三角形以及半椭圆形凹槽的刀柄截面的惯性矩、强度与刀具测力灵敏度之间的关系,并运用MATLAB软件得到了在刀具强度安全域内,使测力系统灵敏度达到最大的刀柄截面形状的相关参数.对比分析六种含有矩形、半圆形复合凹槽的刀柄结构的横截面积、惯性矩、以及相应测力系统的灵敏度等,结果表明:与优化前的刀柄相比较,化后的刀柄结构可以使得测力系统的测力灵敏度提高倍数在(0.46～4.07)范围,而刀柄截面面积降至(0.09～0.84)范围;其中含有台阶层凹槽结构的刀柄优化结果较好,测力灵敏度提高了1.5倍,刀柄截面面积降至0.64倍.     

用于钻铣削过程的四维切削力遥测刀柄

本文介绍了一种适用于钻，铣削加工过程刀具监控系统的测力刀柄，这种刀柄以薄壁圆筒作为感器的弹性元件，切削力信号的测量采用无线电遥测的方法，研制了较先进的感应式电源，解决了供电方式这一阻碍测力刀柄推向实用化的关键问题。     

测力刀柄结构设计与分析

介绍了适用于加工过程中切削力测量的测力刀柄的设计，测力刀柄的弹性元件采用薄壁圆筒的结构形式，成功地解决了灵敏度和刚度之间存在的矛盾。利用有限元分析软件ANSYS进行仿真计算，结果表明所设计的测力刀柄具有良好的静、动态性能。     

新型四维铣削力测量刀柄

介绍了一种用于铣削力测量的新型测力刀柄。这种应变式测力刀柄以薄壁圆筒作为弹性元件，采用无线电遥测的方法传输测量信号，配备了先进的感应式电源，解决了供电方式这一影响测力刀柄实用化的关键问题。标定结果表明，测力刀柄具有良好的静、动态特性。最后，就测力刀柄旋转特性导致的特殊测量结果进行了分析。     

用于铣削加工振动监测的智能刀柄技术研究

针对目前铣削加工自动化的需要和传统振动监测方式使用不方便、可重复性及可移植性差的缺点,开发了用于铣削加工中振动信号监测的智能刀柄系统。通过设计智能刀柄系统并基于Labview平台开发信号采集系统,实现了对铣削加工中振动信号实时监测和预警,并以实验室XS5040立式升降台铣床为例,通过试验验证了该系统的有效性和实用性。     

切削测力平台结构递进式拓扑优化设计研究

微切削加工过程中,切削力是影响加工质量的重要参数。测力仪是动态测量切削力的主要装置,其测力平台部分工作稳定性和准确性对测力仪整体性能起到决定性作用。目前使用的大部分测力平台设计均可以满足宏观较大振幅应力测量要求,但较差的灵敏度和严重的信号衰弱无法满足微切削状态下切削力的微小变化测量。因此提出了一种在满足测力平台弹性体结构强度等要求下,首先以固有频率为目标函数进行单目标优化,将优化后的固有平率作为约束条件,再以应力集中为目标函数进行二次优化的递进式拓扑优化方法;并对优化后的结构进行模态试验,从而证明采用递进式拓扑优化的结构设计方法可以极大的提高测力平台工作时的稳定性、灵敏度和测量精度等性能,同时也拓展了测力平台微切削条件下的适用性。     

用于钻、铣削过程的四维切削力测量刀柄

介绍了适用于钻、铣削加工过程刀具监控测力刀柄的设计思想,比较了几种不同结构测力刀柄的优缺点,提出了用薄壁圆筒作为传感器弹性元件的新构思和四维测力刀柄的静、动态性能。     

嵌入薄膜传感器切削力测量用刀具的结构设计

设计了一种嵌入薄膜传感器切削力测量用刀具模型。对刀柄通过铣槽、钻孔等方式加以改进优化,利用磁控溅射、光刻技术、扩散焊接等方法在45钢弹性薄片基底表面制备Ni80Cr20合金薄膜电阻栅,形成测力应变传感器并安装在刀柄表面。使用ABAQUS软件对模型进行力学仿真分析,结果表明:传感器电阻栅布置在弹性基底中心位置能有效地提高其灵敏度;改进刀具测力系统的输出电压,为初始刀柄输出电压的2.42倍,可以增加传感器输出值;相同条件下,传感器输出电压随弹性基底厚度的减小而增大。     

高灵敏度测力仪及传感器布置形式研究

文中提出一种新型传感器布置形式的测力仪结构,适用铣削、钻削等过程中动态切削力的测量.基于石英晶片不同切型的特点,提出了一种新的测量方式,设计了2种传感器布置形式.对测力仪原理进行分析,建立输入与输出之间的理论输出模型.分别对2种测力仪进行静态性能标定实验,结果表明:2种布置形式的测力仪的线性度和重复性误差均小于1％,并...     

基于无线传输的测振刀柄设计及实验研究

分析了铣削加工中振动信号在线检测技术的不足,提出将无线传感器系统集成在刀柄上实现加工振动检测的方案;提出了用于解决刀柄系统刚度、动平衡问题的刀柄结构设计方案;针对测振刀柄离线供电方式续航能力差的问题,通过综合运用多种休眠方式,实现了嵌入式测振刀柄系统采集传输程序的低功耗设计。设计铣削加工振动检测方式对比实验,验证了刀柄系统振动检测的性能。     

Development of in situ system to monitor the machining process using a piezo load cell

The measurement of cutting force is one of the most frequently used techniques for monitoring machining processes. Its widespread application ranges from tool condition identification, feedback control and cutting system design to process optimization.This paper suggests another system for measuring cutting force in milling processes. Generally, tool dynamometers are taken into account for the most appropriate cutting force measuring tool in the analysis of a cutting mechanism. However, high prices and limited working space make in situ systems difficult for a controllable milling process. Although an alternative suggestion is to use an AC current from a servomotor, it is unsuitable for cutting force monitoring because of a small upper frequency limit and noise.The suggested cutting force measuring system is composed of two piezo load cells placed between the moving table bracket and the nut flange of the ball screw. It has many advantages, such as lower cost and a wider measurement range than the tool dynamometer, over using the built-in feeding system and the low-cost piezo load cell for applying a conventional machining center.This paper focuses on the performance test of a newly developed measuring system. By comparing the cutting force between the tool dynamometer and the system developed from a series of end milling experiments, the accuracy of the cutting force measurement system was verified. Linearity, transverse sensitivity and the upper frequency limit of the system were verified by experiment.     

Dynamic analysis of the 2-DOF planar parallel manipulator of a heavy duty hybrid machine tool

This paper focuses on the dynamic characteristics of the two degree-of-freedom (DOF) planar parallel manipulator of a heavy duty hybrid machine tool. The Newton-Euler approach is employed to derive the inverse dynamic equation of the parallel manipulator. According to the motion planning of the cutting tool, dynamic simulation without cutting force is performed, and the ratio of the masses of counterweights to that of moving parts (not including the counterweight) is optimized. It demonstrates that the manipulator which is designed with over constraint can improve the dynamic behaviour. Furthermore, the cutting force model for face milling is introduced and the dynamic simulation with the dynamic cutting force is carried out. Simulation shows that the oscillation of cutting force is one cause of the vibration of the machine tool in the milling process. In the detailed design, some modification in the structure of the machine tool is made to suppress the vibration.     

Development and evaluation of tool dynamometer for measuring high frequency cutting forces in micro milling

A tool dynamometer is developed for measuring the high frequency cutting forces, and evaluated in micro milling of aluminum 6061-T6 using a tungsten carbide (WC) micro end mill. To improve the accuracy and productivity of the machining process, it is essential to monitor and control the machining process by measuring cutting forces. In order to improve the precision and quality of machined parts, high-speed machining with smaller micro tools is required, causing higher frequency cutting forces. The first natural frequency of tool dynamometers is high enough to precisely measure the high cutting forces. We investigate dynamic characteristics of the tool dynamometer theoretically and experimentally. The measurable frequency range of the developed tool dynamometer was higher than the commercial tool dynamometer, and the measured cutting force signals were not distorted at high-speed of above 60,000 rpm. The results showed that the developed dynamometer is able to measure the static and dynamic force components in high-speed micro milling.     

基于主轴电流的铣削力间接监测方法

实时准确地监测铣削状态对于提高加工质量与加工效率具有重要意义,切削力作为重要的加工状态监测对象,因其监测设备昂贵且安装不便而受到限制,为此提出一种考虑刀具磨损的基于主轴电流的铣削力监测方法.首先基于切削微元理论建立了考虑后刀面磨损的铣削力模型,并通过铣削实验进行铣削力模型系数标定;然后对主轴电流与铣削力的关系进行理论建...     

高速加工热缩加长刀杆与刀具配合铣削力预测

根据热缩加长刀杆与刀具配合精加工与半精加工的特点,利用反向传播神经网络(BPNN)建立高速加工热缩加长刀杆与刀具配合的铣削力模型。模型除了考虑6个主要影响铣削力的加工条件外,还将时间参量引入输入向量,实现了三向铣削力的瞬态预测。通过大量的加工实验获得网络所需的训练和检验样本,并通过编制Matlab程序实现了网络性能评价和网络参数优化。检验结果表明,铣削力预测结果与实际测量结果之间具有很好的一致性,三向分力的平均预测误差均小于0.18,在预测效率和精度上均优于通常所用的解析模型,并具有很好的扩展性能。     

In-Process Tool Fracture monitoring in Face Milling Using Spindle Motor Current and Tool Fracture Index

A new algorithm for tool fracture detection using spindle motor current is suggested for face milling. A tool fracture index (TFI) is suggested to represent the magnitude of tool fracture. Dynamic cutting force variation in the face milling process is measured indirectly using spindle motor current. Even though the dynamic sensitivity of the spindle motor current is low, the cutting force can be correctly represented by the spindle r.m.s current in rough face milling. In rough milling, tool fracture is distinguished well from cutter run-out and transient cutting. The magnitude of tool fracture can be predicted by the proposed tool fracture index using the spindle motor current.     

高速切削刀具的发展现状

对国内外高速切削刀具的发展现状进行了综合评述 ,重点介绍了高速切削刀具材料和高速切削刀具技术 (包括刀具动平衡技术、刀柄系统、刀具安全性、可转位面铣刀结构、刀具监测技术等 )的开发及应用     

螺纹铣削切削力有限元分析及试验

为了研究螺纹铣削法加工钛合金螺纹时切削力随切削参数的变化规律,通过对材料本构关系、刀—屑接触及切屑分离准则进行分析,建立了能反映刀具自转、公转及轴向进给运动的三维螺纹铣削模型。利用该模型对每齿进给量和切削速度对切削力的影响进行分析,结果表明:切削力随每齿进给量的增大而增大,随切削速度增加而减小,且每齿进给量对切削力的影响较为显著。通过螺纹铣削试验对所建立的三维铣削模型进行验证,表明所建立模型的误差最大为14%,可满足实际加工需要。     

Development of a dynamometer for measuring individual cutting edge forces in face milling

Cutting force information may be used for several tasks, such as tool design and trajectory optimization, tool condition monitoring, machinability testing and many others. Accordingly, cutting force measuring has become a crucial activity aimed at enhancing process performance. In this work, the development of an innovative rotating dynamometer for cutting force measurement in milling is illustrated. The device is capable of providing independent triaxial cutting force information from each cutting edge with a good dynamic response. Static and dynamic behavior of a simplified single-edge device was first investigated through the static calibration procedure, pulse tests and preliminary cutting tests. Afterwards, the dynamic properties of the final prototype clamped on the spindle of a high speed milling machine were assessed by means of standard and rotating pulse tests – i.e. pulse tests performed during spindle rotation. Eventually, cutting tests were performed on a benchmark workpiece. The experimental tests highlighted the superior features of the new device.     

面向铣削加工过程在线监测的智能测振刀柄系统

智能化的切削过程监测技术已逐渐成为提升生产效率和产品质量的重要手段。为克服传统有线式振动采集系统振动衰减、安装不便和移植性差等缺陷,开发了面向铣削加工过程在线监测的智能测振刀柄系统,并开展了锤击法模态试验和不同刀具状态下的铣削加工试验,验证了该系统的实用性、可靠性和有效性。