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机床热变形误差及其误差补偿技术 总被引:1,自引:0,他引:1
采用误差补偿技术是提高机床加工精度的一个重要发展趋势,文中对机床的热变形误差状况和误差补偿技术进行了讨论。对误差补偿技术的研究和应用现状、关键技术、应用过程中存在的问题以及将来的发展趋势作了详细的分析和介绍。 相似文献
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数控机床的自动化表现,逐步对精度、工艺等提出较高要求,利用误差补偿技术,控制数据机床,保障数控操作的可靠性。误差补偿技术是提高数控机床误差的一种,完善数控操作,规划误差补偿关键技术中的不足之处,提高疏狂机床误差补偿的应用能力。因此,本文以数控机床为背景,分析误差补偿关键技术。 相似文献
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数控机床几何误差与热误差综合建模及其实时补偿 总被引:8,自引:1,他引:8
为提高数控机床的精度,提出一种数控机床的几何与热的复合误差综合建模方法。通过分析机床在不同温度状态下的误差数据,得到机床误差分布规律;根据几何误差和热误差的不同特性进行误差分离,采用多项式拟合与线性拟合方法建立机床几何误差与热误差的综合数学模型;利用数控(Computer numerical control,CNC)系统的外部机床坐标系偏置功能,应用自行研发的综合误差实时补偿系统进行误差在线实时补偿。该误差补偿方法综合考虑机床几何误差及其在机床不同温度下的变化,全面分析整个温升过程直至热稳态的误差及其变化规律。经检测认证表明,应用该误差补偿方法及其实时补偿系统可使机床在常温下的定位误差由44.1μm降低到3.6μm,补偿91.8%;温升之后的定位误差由26.0μm降低到5.1μm,补偿80.4%,大幅度提高机床的精度。 相似文献
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一、两个不同观点 随着新学科技术的发展,目前出现了不少尖端产品。这些产品中,有些精密零件往往用普通机床和一般方法是难以加工出来的。如何采取措施来提高机床加工精度,有两个观点: (一)分析产生加工误差的各种原因,采取相应措施来消灭或减小其影响。实际上,影响精度的主要因素往往只有少数几个,如机床本身的精度、工艺系统的热变形和弹性变形等;如千方百计提高机床本身精度,采取各种恒温技术和提高工艺系统刚度等措施来解决。这些办法通常称之谓“硬技术”。 (二)采取补偿法,即根据加工工件误差来进行实时补偿。此法可不管误差的根源是… 相似文献
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Thermo-mechanical effects due to changes in the ambient temperature on the shop floor and internal heat sources caused by the manufacturing process significantly contribute to the geometric deviations of a machine tool and therefore, the geometric deviations of the manufactured workpiece. Minimizing these thermally induced geometric deviations is worthwhile since the requested tolerances of machined workpieces become continually smaller nowadays. To investigate the overall deformations of a machine tool structure due to variations in ambient temperature the geometric errors of a five-axis machine tool at different ambient temperatures by means of a portable climate simulation chamber are systematically mapped. While positioning and squareness errors of the linear axes are significantly influenced by the ambient temperature, straightness as well as rotational errors were less sensitive to temperature effects. For the investigated machine tool errors of the two rotational axes are negligible due to an active cooling of these axes. Through numerical error compensation of the linear axes, the geometric errors of the investigated machine tool can be reduced up to 80%. Finally, an outlook how a temperature-dependent compensation could be derived from previously measured compensation fields at discrete temperatures and afterwards applied on-the-fly during manufacturing is given. 相似文献
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双转台五轴机床空间误差补偿技术研究 总被引:1,自引:0,他引:1
几何误差、热误差和切削力误差占到了机床总误差的75%,对这3项误差进行控制是提高机床加工精度的关键所在。以双转台五轴机床的空间误差作为研究对象,通过对加工位置、主要热源及电动机电流等相关因素进行分析,确定空间误差建模所需的位移变量、温度变量和切削力变量。以现有的多种误差建模方法为基础,通过对信息融合技术进行研究,提出一种机床空间误差的多模型融合预测方法,建立综合反映几何误差、热误差和切削力误差的最优空间误差模型。最后以DSP为核心,设计空间误差补偿器,实施空间误差补偿,验证补偿效果。结果显示,建立的模型预测精度较高,残差小于2μm,而实施空间误差补偿后,加工零件的轮廓误差也由15μm降到了5μm,补偿效果明显。 相似文献
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Yuxia Lu M. N. Islam 《The International Journal of Advanced Manufacturing Technology》2012,62(9-12):1071-1085
A traditional model for thermally induced volumetric error of a three-axis machine tool requires measurement of 21 geometric error components and their variation data at different temperatures. Collecting these data is difficult and time consuming. This paper describes the development of a new model for calculating thermally induced volumetric error based on the variation of three error components only. The considered error components are the three axial positioning errors of a machine tool. They are modelled as functions of ball-screw nut temperature and travel distance to predict positioning errors when the thermal condition of the machine tool has changed due to continuous usage. It is assumed that the other 18 error components remain identical to the pre-calibrated cold start values. This assumption is justified by the fact that the machine tool’s thermal status significantly affects three axial positioning errors that dominate machining errors for a machine tool after its continuous use. To demonstrate the effectiveness of the proposed model two types of machining jobs, milling and drilling, on a three-axis horizontal CNC machining centre are simulated and the machined part profiles are predicted. The results show that the thermally induced volumetric error was reduced from 115.40 to 45.37?μm for the milled surface, and the maximum distance error between drilled holes for the drilling operation was reduced from 38.69 to ?0.14?μm after compensation. 相似文献
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针对由几何误差与热误差引起的数控机床工作台与主轴之间相对位置变动的问题,通过试验分析其在不同温度状态下的误差数据,得到机床工作台平面度误差随热变形保持不变的规律,并提出了一种数控机床工作台平面度误差与主轴热误差的综合补偿方法。该方法通过分别建立工作台平面度误差模型和热误差模型,并运用叠加原理建立综合误差补偿模型,对传统固定单位置点建模补偿方法的原理性缺陷进行了改进。结合机床关键部件的实时温度值和刀具位置的实时坐标值,计算出了全工作台各区域各温度阶段的误差补偿值,进而实现了全工作台主轴轴向综合误差的实时补偿。检验及分析结果表明,相比于传统固定单位置点热误差建模补偿方法,该方法所建模型残余标准差减小约7μm,精度提高比例达到50%;单次最大补偿残差减小约11μm,精度提高比例达到60%,大幅度提高了机床的加工精度。 相似文献
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Hui Jiang Kaiguo Fan Jianguo Yang 《The International Journal of Advanced Manufacturing Technology》2014,75(9-12):1279-1289
In order to accurately identify the thermally induced positioning errors, an improved measurement method is proposed based on the repeatability of a machine tool’s temperature rise process. Using this improved measurement method, the mismatches between the thermally induced positioning errors and the machine temperatures can effectively be avoided. To improve the modeling accuracy and efficiency, the least-square fitting of orthogonal polynomial method is used in this research. Using this error modeling method, the thermally induced positioning errors are fitted by 96.7 %. To realize the thermally induced positioning error compensation, a new error compensation method is proposed based on the network. Experimental results show that the thermally induced positioning errors are compensated by 92.6 % compared with no compensation. 相似文献
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本文提出了一种基于自组织原理的主轴热误差补偿策略,它只需根据对主轴热倾斜状态的定性测量结果即可进行定量误差补偿,从而可以大大降低对误差测量精度的要求及测量成本,同时各补偿力间的协调关系根据自组织原则自动建立,简化了补偿算法。经过对某型卧式加工中心主轴热误差进行的自组织仿真补偿,其主轴热倾斜误差减小了92%以上,热偏移误差减小了46%以上。 相似文献
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机床误差是导致圆弧齿线圆柱齿轮齿面误差的主要原因,研究机床误差与齿面误差之间的关系将为机床加工参数反求、齿面误差修正等提供理论依据。基于圆弧齿线圆柱齿轮成型原理建立了齿轮机床结构模型,建立了机床坐标系体系。通过齿坯和刀盘位置误差、刀具形状误差对机床整体误差进行描述,基于啮合原理推导了理想情况下和包含机床误差的齿面方程。研究了齿轮误差曲面计算方法,采用二阶近似曲面和齿面平均误差影响系数分析不同机床误差下误差曲面,研究机床误差对齿面误差的影响规律。通过实例分析了被加工齿轮几何参数不变时和变化时,机床误差对圆弧齿线圆柱齿轮凹齿面误差影响规律。 相似文献
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Mark A. V. Chapman 《Precision Engineering》2003,27(4):516-406
The introduction of B5.54 and ISO230-6 machine tool performance measurement standards is increasing the popularity of laser interferometer diagonal, step diagonal and vector methods for the evaluation and compensation of machine tool errors. This is due to the potential reduction in calibration time, these methods can provide over the more conventional laser interferometer-based linear, angle and straightness measurements taken along lines parallel to the machine’s X, Y and Z axes.
This paper highlights limitations in the results produced by diagonal-based measurements and by the more recently introduced vector or step diagonal methods. The purpose of this paper is to alert potential users of these methods to their limitations so they can make informed decisions as to whether the reduction in calibration time they can provide outweighs the loss of accuracy and detail in the results. It also indicates some of the dangers in using laser diagonal data alone for the compensation of machine tool errors. 相似文献
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螺纹磨床传动链误差的测量与分析 总被引:2,自引:1,他引:1
介绍了螺纹磨床传动链误差测量和分析的方法。由激光测量仪和微机数据采集与处理系统可以精确测量和分析螺纹磨床传动链的误差,为机床校正尺的精密加工和误差在线实时校正提供了依据 相似文献
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为研究数控机床热变形规律,实现数控机床误差在机实时补偿,进行数控机床主轴热变形理论及试验分析,结果表明,数控机床主轴热变形与主轴温变在距热源约1/3位置存在近似线性关系,即主轴热变形存在伪滞后现象,这一结果为数控机床测温点优化布置及热误差鲁棒建模提供理论依据。为验证机床热变形伪滞后现象,对VM850加工中心主轴热漂移误差在机实时检测并建模,通过自主研发数控机床误差在线实时补偿系统对主轴热漂移误差进行实时补偿,经补偿,机床主轴热漂移误差减少90%以上,有效提高了数控机床主轴精度。 相似文献