测力型快速刀具伺服系统的理论与实验研究

发布时间：2018-06-19 06:06

本文选题：金刚石车削 + 快速刀具伺服　；参考：《吉林大学》2017年硕士论文

【摘要】：快速刀具伺服(Fast Tool Servo,简称FTS)机构可实现刀具相对旋转工件的快速高频往复运动,在非回转对称光学自由曲面的精密超精密加工和机床加工误差补偿中具有较为广泛的应用需求。切削力对于机械加工质量有着至关重要的影响,无论是利用FTS实现误差补偿还是用于自由曲面加工,测量切削力都是十分必要的。准确测量切削力有助于揭示FTS切削加工机理,因此在基于FTS的单点金刚石车削机构中集成切削力的测量功能是十分必要的。现有的车削切削力测量主要有两种:一种是将测力装置安装在主轴上,另一种是将测力装置安装在刀座上。FTS是一种柔性加工机构,切削厚度始终在高频变化,对于利用FTS的车削,无论将测力装置安装在FTS的底座还是靠近刀具端,现有的技术方案都不能有效地进行切削力测量。如何准确测量FTS切削力已成为目前急待解决的问题。论文系统评述了国际上针对FTS开展的系列研究,主要涉及FTS的工作原理、结构、种类、发展历程和应用前景等,重点分析了国外现有的测力型FTS的研究现状,并指出了存在的问题。为解决FTS切削力的测量问题,本文基于一种具有Y向和Z向切削力测量功能的FTS进行了切削力测量误差分析,总结出了测力型FTS的设计经验,分析了各参数与切削力测量误差的关系。设计出了一种具有三向切削力测量功能的FTS,建立了切削力真值与测量值的关系,通过静态标定测试验证了测力准确性,并通过在线切削测试测得其切削力。本文的研究内容主要包括如下。1.对比分析了压力传感器前置型和后置型两种测力FTS的切削力测量的准确性,设计了一种具有两向切削力测量功能的压力传感器前置型FTS,并基于该FTS进行了切削力测量误差分析。2.研制了一种三向测力型FTS,提出了一种等腰三角形T型布置的三向切削力测量方案,通过对切削力测量系统的动力学分析,分别建立了三向切削力测量模型。基于频率响应函数,提出了一种误差补偿方法。3.设计并研制了一种四自由度龙门型压电激振器,可以对空间各个方向实现不同频率的激振力的施加,可有效满足静态标定实验的需求。进行了一系列的机下试验,验证了三向测力型FTS的工作性能。4.搭建了三向模拟切削力静态标定系统,实施了模拟切削力激振实验,测出了各项切削力的测量误差。应用所述的三向测力型FTS,加工出了一系列的平面和自由曲面,并测出了相应的切削力。本文的贡献在于:提出了一种针对测力型FTS的切削力测量误差分析方法,设计并制作出了一种具有三向切削力测量功能的FTS机构,提出了一种三向切削力误差补偿方法。
[Abstract]:Fast tool Servo (FTS) mechanism can realize the rapid high frequency reciprocating motion of the tool relative to the rotating workpiece. It has more extensive application requirements in the precision ultra-precision machining of the non-rotational symmetric optical free-form surface and the error compensation of the machine tool. Cutting force plays an important role in machining quality. It is necessary to measure cutting force for error compensation by FTS and for free-form surface machining. Accurate measurement of cutting force is helpful to reveal the mechanism of FTS cutting, so it is necessary to integrate the measuring function of cutting force in single point diamond turning mechanism based on FTS. There are two kinds of cutting force measurement: one is to install the force measuring device on the spindle, the other is to install the force measuring device on the tool holder. FTS is a kind of flexible machining mechanism, and the cutting thickness always changes at high frequency. For turning with FTS, the existing technical scheme can not effectively measure the cutting force, whether it is installed in the base of FTS or near the tool end. How to accurately measure the cutting force of FTS has become an urgent problem to be solved. This paper systematically reviews the series of studies on FTS in the world, which mainly involve the working principle, structure, category, development and application prospect of FTS, and analyzes the current research situation of the force-based FTS abroad. The existing problems are pointed out. In order to solve the problem of measuring cutting force of FTS, this paper analyzes the error of cutting force measurement based on a kind of FTS which has the function of measuring cutting force in Y direction and Z direction, and summarizes the design experience of force measuring type FTS. The relationship between the parameters and the measuring error of cutting force is analyzed. A kind of FTS with the function of three direction cutting force measurement is designed, and the relationship between the true value of cutting force and the measured value is established. The accuracy of force measurement is verified by static calibration test, and the cutting force is measured by on-line cutting test. The main contents of this paper are as follows. 1. This paper compares and analyzes the accuracy of cutting force measurement of pressure-sensor and post-type FTS, designs a pressure-sensor front-end FTS with the function of two-direction cutting force measurement, and analyzes the error of cutting force measurement based on the FTS. In this paper, a kind of three direction force measurement model FTS is developed, and a measuring scheme of three direction cutting force with T shape arrangement of isosceles triangle is put forward. Based on the dynamic analysis of the cutting force measurement system, the three direction cutting force measurement model is established respectively. Based on the frequency response function, an error compensation method. A kind of four-degree-of-freedom gantry piezoelectric vibration exciter is designed and developed, which can apply the exciting force of different frequencies in different directions of space, and can meet the demand of static calibration experiment. A series of machine-down tests were carried out to verify the performance of three-direction force-measuring FTS. 4. The static calibration system of three direction simulated cutting force is built, and the experiment of simulating cutting force exciting vibration is carried out, and the measuring error of each cutting force is measured. A series of plane and free surface are machined by using the three direction force measurement type FTS, and the corresponding cutting forces are measured. The contributions of this paper are as follows: a method for error analysis of cutting force measurement for force-measuring FTS is proposed, a FTS mechanism with the function of three-direction cutting force measurement is designed and fabricated, and a method for compensating the error of three-direction cutting force is proposed.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG659

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