华中HED-21S数控实验台螺距误差补偿的研究

螺距误差是造成数控机床加工精度下降的重要原因之一.针对华中HED-21S数控实验台产生的螺距误差,通过分析螺距误差补偿原理,对z轴误差进行了补偿.实验结果表明:利用螺距误差补偿消除传动部件间隙,能够提高数控机床的定位精度和重复定位精度.     

基于HNC-818B数控转台螺距误差补偿的研究

介绍了数控转台的螺距误差补偿原理和自准直仪误差测量系统,对配备HNC-818B系统的数控转台进行了定位精度检测,并对数控转台进行了螺距误差补偿。结果表明:螺距误差补偿可以提高数控转台的定位精度和重复定位精度。     

SINUMERIK 810D／840D数控系统螺距误差补偿技术研究

分析了数控机床螺距误差产生的原因及误差补偿原理,针对SINUMERIK 810D/840D数控系统,详细介绍了螺距误差补偿相关的机床参数、系统变量、补偿方法与步骤.最后,介绍了螺距误差补偿应用的范围.     

普及型数控系统直线误差的研究与应用

通过分析普及型半闭环数控系统的直线误差,指出传动系统的反向间隙和螺距误差是影响定位精度和重复定位精度的主要原因.阐述了数控系统反向间隙补偿和螺距误差补偿的原理,提出了发挥数控系统软件功能,控制直线误差,是提高行业加工精度的经济而有效的方法.研究了反向间隙测量方法和螺距误差补偿原点设置的原则.以GSK数控系统为例,详细介绍了反向间隙补偿、螺距误差补偿相关的误差测量方法、数控系统参数设置、变量设置等内容,并列举了具体操作实例.     

LNC-M510i螺距误差补偿功能的应用研究

螺距误差的大小会影响机床的定位精度,通过数控系统提供的螺距误差补偿功能可以对机床的螺距误差进行修正,从而提高机床的定位精度。基于LNC-M510i数控系统进行螺距误差补偿技术的研究,为实际中进行螺距误差补偿的使用者提供一定的参考。     

XK714/1数控铣床螺距误差补偿

数控机床的定位精度是影响其高精度性能的一个重要方面,因而也是数控机床验收和检测的重要指标之一。螺距误差是影响定位精度的重要因素,通过螺距误差补偿能够有效改善机床的定位精度和加工精度,对数控机床的使用和维护具有重要意义。对数控机床反向间隙补偿和螺距误差补偿的原理及测量方法进行深入研究,并针对XK714/1数控铣床FANUC 0M系统的螺距误差进行补偿,取得了良好的补偿效果,说明对滚珠丝杆传动机构的反向偏差与螺距误差进行补偿是恢复和提高机床精度的一种重要手段。     

微机自适应控制提高丝杠螺纹加工精度

通过对车床加工丝杠螺距误差的分析,提出了应用自适应控制原理,在数控车床上不另设误差补偿机构,利用微机实现螺距误差在线动态测量和实时补偿校正。实践证明,这是一种有效的误差补偿校正方法,具有较高的性能价格比和推广使用价值。     

三米数控车床实现螺补功能的原理及方法

在数控车削长丝杠时，采用螺距误差补偿的方法来补偿后面淬火工序所引起的螺距误差。文章介绍了该方法的补偿原理以及实际操作方法。     

微机自适应控制提高丝械螺纹加工精度

通过对车床加工丝杠螺距误差的分析，提出了应用自适应控制原理，在数控车床上不别设误差补偿机构，利用微机实现螺距误差在线动态测量和实时补偿校正，实践证明，这是一种有效的误差补偿校正方法，具有较高的性能价格比和推广和价值。     

基于FANUC系统的螺纹误差测量与补偿

螺距误差是影响数控机床加工精度的重要因素.根据误差产生原因,介绍数控机床螺距误差补偿的依据和原理;以某一型号数控车床为例,详细说明了利用激光干涉仪实现误差测量及补偿的具体方法.结果表明,该补偿方法能较大程度提高数控机床的加工精度.     

基于跨齿分度法的大型齿轮齿距误差分析及补偿研究

针对成形法加工大型圆柱齿轮中的齿距误差，根据大型齿轮齿距精度的评定方法，分析机床热变形误差、刀具磨损误差及回转台分度误差对齿轮齿距误差的影响，研究齿距分度、连续分度对齿轮齿距误差的影响规律。基于跨齿分度，优化齿轮精加工工序，以降低齿距误差，并对优化效果进行试验验证。结果表明：跨齿分度法可有效降低因机床热变形、刀具磨损、回转工作台分度分辨率导致的齿轮齿距误差，较大幅度提高大型圆柱齿轮齿距的加工精度。     

Identification of two different geometric error definitions for the rotary axis of the 5-axis machine tools

Geometric errors are clearly among the critical error sources in 5-axis machine tools and directly contribute to the machining inaccuracies. According to the definition of geometric errors of the rotary axis, different understandings have been exist in published studies. It is extremely dangerous as it makes the comprehension of the geometric errors ambiguous and may make the geometric error identification and compensation less effective. This phenomenon has not been noticed so far. In this paper, two different commonly used geometric error definition and modeling methods are firstly identified and analyzed, named as “Rotary axis component shift” and “Rotary axis line shift”. The features and relationships of these two error modeling methods are analyzed. After a detailed comparison, “Rotary axis component shift” is more suitable to definite the geometric errors of rotary axis. An experiment has been conducted on a 5-axis machine tool to show the correctness of our work. The results show that the identified geometric errors of rotary axis based on the two error models are greatly different and need to be concerned.     

利用螺纹副驱动脱内螺纹的注射模设计

以螺旋传动可将旋转运动转变为直线运动为设计依据,采用与内螺纹相等螺距的梯形螺纹副为主要机构,使螺纹型芯在转动的同时往轴向方向直线运动,实现螺纹型芯的顺利抽芯和复位,同时对抽芯行程和复位行程的控制方法以及模具零件的设计作了介绍。实践证明:模具结构设计合理,动作可靠。     

Error map construction for rotary axes on five-axis machine tools by on-the-machine measurement using a touch-trigger probe

Position-dependent geometric errors, or “error map,” of a rotary axis represent how position and orientation of the axis of rotation change with its rotation. This paper proposes a scheme to calibrate the error map of rotary axes by on-the-machine measurement of test pieces by using a contact-type touch-trigger probe installed on the machine's spindle. The present scheme enables more efficient and automated error calibration, which is crucial to implement periodic check of rotary axes error map or periodic update of its numerical compensation for five-axis machine tools. The uncertainty analysis of the error calibration is also presented with a particular interest in the influence of error motions of linear axes. The experimental demonstration is presented.     

精密加工中心直线轴复合误差建模研究北大核心

为提高精密机床加工精度,针对直线轴几何误差与热误差两类重要误差项进行分析,并提出一种复合定位误差建模方法。首先对两端固定式丝杠进给系统的热误差机制进行分析,建立正弦函数误差表达式,利用有限元法提取丝杠表面温度并作为输入量代入到热误差模型中。利用切比雪夫多项式建立静态几何误差预测模型。将两模型叠加,得到复合定位误差模型。对精密加工中心直线轴进行检测实验,实验值与预测模型对比后发现预测精度达到85%以上,验证了复合误差模型具有较高的预测精度,为直线轴定位误差补偿提供了参考。     

基于西门子828D数控系统的直驱转台设计及误差补偿

设计一套直驱转台,在828D数控系统下进行调试,分析转台分度误差产生的原因,并使用828D数控系统的螺距补偿功能对转台进行了分度精度补偿。     

NC data generation for 4-axis machine tools equipped with rotary angle head attachments to produce variable pitch screws

A kinematic model to generate the NC data for 4-axis machine tools equipped with rotary angle head attachments has been developed in order to produce a double threaded variable pitch screw. The 4 × 4 homogeneous transformation matrix is employed in the derivation of the ability functions of the machine tool and in the generation of the desired cutter locations. NC data equations are obtained by equating the corresponding elements of the ability function of the machine tool and the desired tool location matrices. The machine tool settings for a screw are investigated and then this screw is machined as an illustrative example. This general methodology is applicable to various types of cams possessing conical or cylindrical meshing element(s). It also combines the activities of design and manufacturing, thus making the production process more flexible, automatic, and controllable.     

A machining test to calibrate rotary axis error motions of five-axis machine tools and its application to thermal deformation test

This paper proposes a machining test to parameterize error motions, or position-dependent geometric errors, of rotary axes in a five-axis machine tool. At the given set of angular positions of rotary axes, a square-shaped step is machined by a straight end mill. By measuring geometric errors of the finished test piece, the position and the orientation of rotary axis average lines (location errors), as well as position-dependent geometric errors of rotary axes, can be numerically identified based on the machine׳s kinematic model. Furthermore, by consequently performing the proposed machining test, one can quantitatively observe how error motions of rotary axes change due to thermal deformation induced mainly by spindle rotation. Experimental demonstration is presented.     

Construction of an error map of rotary axes on a five-axis machining center by static R-test

This paper proposes an efficient and automated scheme to calibrate error motions of rotary axes on a five-axis machining center by using the R-test. During a five-axis measurement cycle, the R-test probing system measures the three-dimensional displacement of a sphere attached to the spindle in relative to the machine table. Location errors, defined in ISO 230-7, of rotary axes are the most fundamental error factors in the five-axis kinematics. A larger class of error motions can be modeled as geometric errors that vary depending on the angular position of a rotary axis. The objective of this paper is to present an algorithm to identify not only location errors, but also such position-dependent geometric errors, or “error map,” of rotary axes. Its experimental demonstration is presented.