基于单片机的丝杠螺距误差测量应用

在分析丝杠螺距误差测量基本原理的基础上,简述了由单片微机组成的滚珠丝杠螺距误差动态测试系统,并开发了计算机辅助自动分析测控软件。该软件具有良好的人机操作界面,实现了丝杠的自动测量、自动分析、自动精度验收评定。经实际应用,检测效率高,操作性强,性能稳定可靠。     

模拟工况下滚珠丝杠副精度检测方法研究

滚珠丝杠副是机械传动中重要的传动部件,滚珠丝杠副精度的检测有着极其重要意义。设计了以长光栅作为长度基准,圆光栅作为角度基准的滚珠丝杠精度动态检测装置。检测装置可模拟实际加载情况下对丝杠精度的测量。根据行业相关标准,采用最小二乘法原理建立数学模型简化了行程变动量的求解过程。提出了模拟工况下对滚珠丝杠副传动精度检测的方法,并在自行研制的精度检测装置上实现滚珠丝杠副数据采集处理,实验所得误差值与要求的误差值相对比。结果表明,该方法简单且易于计算机数据处理,能满足滚珠丝杠副动态精度的检测,具有较高的实际应用价值。     

滚珠丝杠副直驱加载位置精度测试研究

为实现滚珠丝杠副精度寿命测量,设计了直驱加载加速衰退测试系统。研究了滚珠丝杠副位置精度测量原理及计算方法;基于开放式数控系统,开发了测控一体系统。由直线电机模拟滚珠丝杠副动态载荷,进行了加速跑和测试实验,对测量结果进行了拟合分析。结果表明,文中采用的方法能够快速实现滚珠丝杠副的加速跑和测试,丝杠位置精度寿命退化符合偏移指数规律。     

滚珠丝杠的智能化研究进展

数控机床进给系统的智能化的状态检测、故障诊断以及自修复的能力可以提高数控机床工作的稳定性和可靠性,减少数控机床加工过程中出现的问题。滚珠丝杠是数控机床进给系统的重要组成部分,其精度与性能直接影响着数控机床的加工质量,滚珠丝杠的智能化发展也对数控机床的智能化发展有着非常重要的作用。综述了滚珠丝杠智能化的研究现状,分析了滚珠丝杠的动态测量和静态测量区别及优缺点;概述了基于数学模型和基于人工智能两个方面的故障诊断技术在滚珠丝杠中的应用;阐述了滚珠丝杠弹流润滑的机制以及通过润滑剂添加剂进行自修复的方法,阐明了滚珠丝杠的状态检测与故障诊断技术及自修复技术所存在的问题,展望了滚珠丝杠智能化的发展方向。     

数字刀具测量系统的研究

刀具的几何参数是影响数控机床加工精度和生产效率的重要因素。研究了基于计算机视觉检测技术的高精度刀具测量系统,分析了运行原理和功能模块,并对关键技术做了论述。系统实现了对刀具的刀尖切削特征点、圆弧半径和切削角参数的自动精确测量,并将数值反馈到数控机床刀具数据库,具有较高的效率、精度和自动化程度。实验结果证明,系统测量重复性精度可达3μm。     

激光丝杠动态检查仪简介

本文介绍了一种双频激光、圆光栅高精度测量滚动丝杠（副）螺旋线误关的仪器仪器测量过程实现了动态采样和自动数据处理。     

一种能定量测量自动评级的电脑评片系统

本文提出了一种将计算机图像处理、模式识别、数据库技术和射线照相检测技术相结合的,只需要少量人工介入即可实现精确定量测量和自动分析评级的电脑评片系统。     

精密滚珠丝杠螺旋线误差动态测量方法的研究

介绍了“精密滚珠丝杠螺旋线误差动态测量仪”的总体结构设计和测量系统的软、硬件实现方法。通过对测量结果的多次试验,并对丝杠螺旋线误差曲线进行了温度修正和滤波处理,为用户提供了可靠的检测报告。     

预紧力对滚珠丝杠副精度影响的研究

为了更好的研究滚珠丝杠副的精度损失规律,提出了一种滚珠丝杠副精度损失的计算方法。该计算方法是在改进的运动学基础上结合滚珠与滚道间滑动特性与接触特性建立的。由于滚珠丝杠副的预紧力无法通过普通方法直接测量且运行过程中预紧力是不断变化的,计算过程中也考虑了预紧力的变化并使用摩擦力矩的测量值计算预紧力。此外,在专为滚珠丝杠副精度损失测量而设计的试验台上进行了滚珠丝杠副精度损失试验。将试验数据与计算数据进行对比与分析,结果表明该计算方法可以计算滚珠丝杠副的精度损失并预测其精度变化趋势。     

移动切削力激励下的大型丝杠硬旋铣系统动态响应分析

以六米大型丝杠硬旋铣系统为研究对象,运用全局假设模态法,建立了丝杠工件在断续周期性移动切削力激励和卡盘、浮动支撑、抱紧装置,尾架约束下的动力学模型,分析了丝杠工件在移动切削力激励下切削全程的动态响应特性,以及抱紧及支撑装置对丝杠工件切削全程中各切削点动态响应幅值均值的影响.结果表明:抱紧装置的移动对丝杠工件的动态响应影响较小,而浮动支撑的升降显著影响工件系统的动态特性;丝杠工件的动态响应不是随抱紧刚度的增大而单调减小,选择合理的抱紧刚度可以减小工件的装夹变形,同时工件的动态特性也能满足加工精度的要求.     

Investigation into effect of thermal expansion on thermally induced error of ball screw feed drive system of precision machine tools

In order to investigate the effect of thermal expansion on the ball screw feed drive system of a precision boring machine tool, theoretical modeling of and experimental study on thermally induced error along with heat generation characteristics are focused in this paper. A series of thermal experiments are conducted on the machine tool to measure and collect the thermodynamic data with the feed drive system operating at different speeds. Based on the heat generation and transfer analysis of ball screw system, thermal expansion of screw shaft in the axial direction is modeled mathematically. Relationships between the thermal error and axial elongation are established to characterize the thermal error distribution considering the thermal expansion coefficient as a temperature-variant parameter. It turns out that the thermal error varies with different working positions through the ball screw length and working time nonlinearly, and there definitely exists certain transform from the thermal expansion to the thermal error obtained by measurement. In addition, regression analysis is employed to carry out the theoretical modeling of thermal error with the temperature data of the critical heat generation points. The relations between temperature rise and thermal error are formulated directly while taking the thermal expansion as an implicit variable. Experiments under a different condition are preformed and the proposed methods for thermal error modeling prove to be effective and accurate enough to be used in the machining process as well.     

The development of a high-speed spindle measurement system using a laser diode and a quadrants sensor

Reducing the manufacturing time is the trend of precision manufacturing, and the precision of a work-piece is very important for manufacturing industry. High-speed cutting is becoming more widely used and the high-speed spindle is a very important element, whose precision may affect the overall performance of high-speed cutting. Most of the studies on high-speed cutting are focused on the cutting force, the vibration of the spindle and the effects of the spindle's thermal expansion; however, the measurement of the high-speed spindle continues to use the conventional spindle measurement method.As with the measurement of the high-speed spindle, more strict demands are set on the dynamic balance of cutting tools and the bandwidth of the measurement systems when compared with common spindles. The capacitance displacement sensor has been employed for the spindle error test. The precision of the measurement system is limited by the reference (such as a master ball or a master cylinder). Also the capacitance sensor and the reference must be grounded together. This paper presents a simple spindle measurement system using a laser diode and a quadrants sensor, with accuracy up to 1 μm, within 300,000 rpm for various spindles. The system does not need any reference and it is easy to set up. This system can be applied to measure the spindle errors, the spindle speed and the spindle indexing.     

Autonomous form measurement on machining centers for free-form surfaces

This research aims at developing a measurement technique on machining centers for 3D free-form contours. An autonomous measuring principle is proposed and a prototype measuring device applicable to a machining center has been produced. In the measuring device, a laser displacement detector in a narrow range, which directly detects the distance from a point on the measured surface to the reference position of the detector output, is put together with the movable part of a linear encoder on the nut of a ball screw. A stepping motor controls the laser detector position to keep the output at the central value of the detector measuring range by driving the ball screw. Both the motor and the fixed part of the linear encoder are placed on the device base. The linear encoder detects the moving displacement of the screw nut, i.e. the position change of the laser detector. By installing the base on the spindle of a machining center and moving the table along a plane perpendicular to the spindle, the laser detector can automatically follow the contour of a work piece set on the table and measure its form along a scanning line, simultaneously. The displacement of a measured point relative to the reference position of the linear encoder output on the spindle side is just equal to the sum of the outputs of the two sensors, i.e. the laser detector and the linear encoder. Moreover, a simple experimental approach to identifying the sensing direction errors for an assembled measuring device is developed. The results of some experiments are also shown, which sufficiently demonstrate the effectiveness of the proposed inspection method and error identification approach.     

基于复合直梁型柔性铰链的导轨直线度测量研究

刚度是影响柔性铰链机械性能的重要参数指标,建立复合型柔性铰链拉伸刚度模型,在不同参数、不同尺寸条件下计算其解析解,通过ANSYS Workbench对其进行静力学仿真,分析各个结构参数对其刚度的影响,同时得出该种复合柔性铰链在同等尺寸及力的作用下比传统双边平行铰链有较大的输出位移。在解析解与仿真结果误差较小的情况下,设计出一种参数最优化的复合柔性铰链并搭建了测量平台,对滚珠丝杆驱动的导轨进行了直线度误差测量,将其结果和激光干涉仪测量结果对比,验证了基于该柔性铰链搭建的测量平台满足直线度的测量需求。     

线阵电荷耦合器技术在自动测长系统中的应用

介绍用线阵电荷耦合器件(CCD)技术设计的型材在线实时测量系统。采用粗测和精测相结合的方法，解决了较大长度范围内精确测量问题。详细介绍动态在线非接触式测控系统的基本工作原理及软硬件组成。实测结果表明其测量精度高、效果好，能满足快速流水线的现场检测。     

龙门加工中心滚珠丝杠传动系统的温度场和热变形分析

龙门加工中心滚珠丝杠热变形是机床误差的重要原因之一.根据企业龙门加工中心丝杠传动系统的实际工作状态,建立了丝杠支座温度场和热变形的ANSYS分析模型.通过施加移动热载荷,在ANSYS中求解了丝杠的温度场和热变形,获得丝杠表面温度场分布趋势以及丝杠进给方向的热变形变化情况,在此基础上提出相应的改进建议,为机床优化设计和提高机床的加工精度提供了依据.     

Compensation of Axial Vibrations in Ball Screw Drives

This paper presents a precision control strategy for ball screw drives. Axial vibrations are modeled and actively compensated in the control law, which enables the realization of high positioning bandwidth. Lead errors, arising from imperfections of the screw, are modeled and removed from the loop by offsetting their effect from the command trajectory and position feedback signals. Effectiveness of the proposed strategy is demonstrated in high speed tracking experiments conducted on a ball screw drive, where a linear positioning accuracy of 2.6 um has been maintained while traversing the axis at 1000 mm/s feed with 0.5 g acceleration.     

滚珠丝杆进给系统的多自由度柔体建模研究

考虑滚珠丝杠进给系统的机电耦合特性,对系统结构进行分块细化,降低系统的耦合复杂度,提出了丝杠进给系统的分-总式建模方法。将滚珠丝杆系统作多自由度柔体处理,综合考虑系统的弯曲、扭转及沿丝杠轴向的变形,基于动力学理论,采用瞬时变分法,推导出滚珠丝杠进给系统动力学模型,分析得出基于系统结构柔性影响与丝杠轴弯曲剪切综合变形而引起的耦合影响,不同于以往滚珠丝杠进给系统集中质量模型(混合模型)下各向振动之间的耦合影响及振动方程。通过振动实验,借助主分量分析法验证了所建立的动力学模型的正确性,为后续的丝杠进给驱动系统的动力学分析提供研究依据。