高速立铣切削刀具温度场建模与实时在线温度测量技术研究

发布时间：2018-01-23 23:18

本文关键词： 高速铣削刀具温度场建模实时在线测温热电偶无线传输　出处：《哈尔滨理工大学》2015年博士论文　论文类型：学位论文

【摘要】：在机械加工切削过程中,切削热及其产生的切削温度直接影响刀具的磨损和寿命,同时也影响工件的加工质量和表面质量。其中,切削温度的在线测量对于研究由切削热导致的刀具磨损和寿命减少具有重要意义。尤其是对于正处在切削过程中的刀具,采用刀具温度实时在线测量技术能监控其切削温度变化,为加工安全提供有力保障,为加工质量提供技术支撑。目前,切削过程中的在线测量方法还不能解决高速切削中刀具定点温度实时在线连续测量的问题。因此,研究一种既可以进行连续单点温度测量,又不改变主轴结构,同时能够实时获得温度数据的方法是非常必要的。这对研究切削热导致的刀具磨损和寿命减少、监控切削过程刀具切削温度变化以保证加工安全和加工质量等具有重要意义。针对高速切削过程,本文采用热电偶测温方法,以熔焊方式在刀具后刀面切削温度场最高温度点位置固定热电偶结球,将热电偶尾线引入放置于改进后的刀柄内的下位机,采用无线传输方式发送温度测量数据,利用无线路由器将温度测量数据送至上位机进行处理,实现高速切削中刀具定点温度实时在线连续测量。本文在提出系统总体方案的基础上,通过系统分析提出具体性能指标要求,展开了深入的理论和实验研究。针对高速立铣刀的特点,采用热源法建立温度场的数学模型,利用有限元软件仿真立铣刀的温度场分布。再根据数学模型和仿真结果,分析切削热的产生及其导致的刀具升温,从而判断温度最高点的位置,为确定立铣刀固定测温点位置提供依据,还可为立铣刀的结构优化设计、切削实验设计等,提供理论依据。针对成熟可靠的热电偶测温方法,研究并实现热电偶与被测刀具的安装方法,通过电容焊机将热电偶结球焊接在位于刀具后刀面上邻近主切削刃的预埋槽内,在不破坏原有刀具强度和温度场的前提下,实现刀具温度场定点温度的实时在线连续感知;研究并实现热电偶尾线引出和下位机安装方法,将热电偶尾线通过刀具内冷孔引出至刀柄内,改进刀柄结构提供下位机安置空间,同时符合其原有技术标准,实现热电偶与下位机相对位置固定的安装连线;研究并实现高速数据采样方法,将热电偶输出热电势同时引入两片微小型模拟数字转换器,通过双通道并行时间交替采样方法将采样率提高一倍,实现高速数据采样;研究并实现高速高可靠无线数据传输方法,采用现有UDP协议,有针对性地引入监督位和监督矩阵,由下位机对温度测量数据进行分组、打包和发送,由上位机对接收数据进行纠错、组合和处理,形成改进的UDP协议,消除原有的数据乱序和错包现象,实现高速高可靠无线数据传输。针对测温系统中,由RC网络、模拟数字转换和冷端补偿所构成的环节,建立其数学模型并进行静态特性和动态特性分析;利用仿真软件进行特性仿真,给出系统时间常数和幅值损耗0.1%时的最高频率;根据所建立的数学模型,按照温度信号传递路径,进行不确定度分析,给出系统量程和测量精度。针对所研制的高速立铣切削刀具定点温度实时在线连续测量装置,进行无线数据传输测试实验,验证在经过改进UDP协议处理之后,上位机接收到的数据无错包无乱序,具有高速传输特性;通过精密温度校验炉完成测温系统标定,给出测温系统静态测量误差;采用本文测温系统进行高速立铣刀具定点切削温度实时在线连续测量实验,对测温系统进行实验验证。
[Abstract]:In the machining process, cutting temperature and cutting heat generated directly affects the tool wear and life, but also affects the machining quality and the surface quality of the workpiece. The on-line measurement of cutting temperature has important significance for the study of less reduction caused by cutting heat cutting tool wear and life. Especially for the cutting tool in the process of using real-time online measurement technology can monitor the temperature of the cutting tool temperature changes, providing a powerful guarantee for the safety in production, to provide technical support for the quality of products. At present, in the process of cutting the online measurement method can not solve real-time high-speed cutting tool point temperature continuous measurement. Therefore, the research of both can be a continuous single point temperature measurement, but also can not change the spindle structure, and method can obtain the temperature data in real time. It is very necessary to research cutting To reduce the heat caused by cutting tool wear, cutting temperature monitoring cutting process has important significance to ensure the safety and quality of processing processing for high speed cutting process, this paper adopted thermocouple temperature measurement method, the welding methods tool face the maximum temperature point fixed thermocouple in the tool after heading, the thermocouple tail line introduction the machine is placed on the improved handle in the temperature measurement data sent by the wireless transmission mode, the router will use wireless temperature measurement data is sent to the host computer for processing, high speed cutting tool point temperature real-time online continuous measurement. In this paper, the overall design of the system, through the analysis of the system put forward specific performance requirements the index, carried out in-depth theoretical and experimental research. According to the characteristics of high speed milling cutter, temperature field is established by the mathematical method of heat source The model, the temperature field distribution of mills using finite element simulation software. According to the mathematical model and simulation results, and cause analysis of heating heat cutting tool, in order to determine the highest temperature point position, provide a basis to determine the vertical temperature fixed point cutter, also for structure optimization design of the cutter, cutting experiment design, provide a theoretical basis for thermocouple is mature and reliable, the research and implementation of the installation method and tool thermocouple measured by capacitance, welding thermocouple will be heading weld adjacent the main cutting edge in the flank of the embedded groove, the tool does not destroy the original strength and temperature field under the premise the tool temperature field point temperature real-time continuous perception; the research and implementation of thermocouple tail line extraction and machine installation method, the thermocouple tail line through the tool cooling hole leads to The knife handle, provide machine tool structure and improve the placement space, with its original technical standards, implementation of thermocouple and lower machine fixed position relative to the mounting line; the research and implementation of high speed data sampling method, the thermocouple output thermal potential while introducing two small analog to digital converter through dual channel parallel time interleaved sampling method sampling the rate doubled, to achieve high-speed data sampling; research and implementation of high speed and high reliable wireless data transmission method, using the existing UDP protocol, the introduction of targeted supervision and supervision of the matrix, temperature measurement data are grouped by machine, packing and delivery, to receive data for error correction by the host computer, and combined treatment a modified UDP protocol, eliminating the original data reordering and packet error phenomenon, high speed and high reliability of wireless data transmission. In this system, the RC network model A quasi digital conversion and cold end compensation links, establish its mathematical model and analysis of static and dynamic characteristics; the characteristics of simulation using simulation software, the highest frequency gives the system time constant and amplitude loss at 0.1%; according to the established mathematical model, according to the temperature signal transmission path of uncertainty analysis this system range and measurement precision for high speed milling cutting tool developed by the fixed-point temperature real-time online continuous measurement device, wireless data transmission test, verification in the improved UDP protocol after receiving PC data without error packets without reordering, with high-speed transmission characteristics; the precise temperature calibration furnace complete calibration of temperature measurement system, temperature measurement system are static measurement error; the temperature measurement system of high speed milling cutter cutting temperature in real-time fixed line continuous measurement Experiments are carried out to verify the temperature measurement system.

【学位授予单位】：哈尔滨理工大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TG71

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