共查询到18条相似文献,搜索用时 171 毫秒
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介绍了机械零件刚度模糊可靠性设计变形分布参数和刚度隶属函数的确定,导出了零件刚度模糊可靠度的计算公式,并通过机床主轴模糊可靠性设计实例说明机械零件模糊可靠性的计算方法. 相似文献
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机床主轴的公差建模很少同时考虑切削力与摩擦热耦合变形的影响,导致公差模型与工程实际存在较大差异,难以保证机床主轴加工精度的问题。为此,研究一种基于热力耦合变形的机床主轴公差建模方法。根据机床主轴的实际工况,运用小位移旋量理论表达特征的几何变动,建立主轴原始几何误差的Jacobian-Torsor公差模型;根据几何变动修正Jacobian-Torsor公差建模,增加典型配合特征的公差变动表示模型;利用ANSYS计算主轴在切削力与摩擦热耦合作用下的变形量;将结果引入修正的Jacobian-Torsor模型,得到热力耦合变形下的机床主轴公差模型。结果表明:主轴与轴承的装配间隙在径向y方向上的平动量减少0.009 mm,沿着径向的转动量减少0.000 8 mm,过盈增大,加快了主轴的磨损,影响主轴的回转精度。所设计的模型可为机床主轴的公差设计提供参考,并可预测和改善主轴的工作性能。 相似文献
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机床主轴的模糊优化设计 总被引:1,自引:0,他引:1
机床主轴在传动过程中,具有速度波动,为减少速度波动引起的动载荷影响,设计时要在传递转矩一定的情况下,使质量最小,本文讨论了主轴设计过程中的模糊因素,建立了以截面积最小的模糊优化设计模型,运用模糊理论和方法获得最优解。 相似文献
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现有技术中的机床主轴质量比过大、惯性矩大,不适用于高速加工。而碳纤维主轴轻质高强,有利于减小芯轴的转动惯量,在确保主轴高速加工中快速响应的同时还可以很好地控制精度。以碳纤维主轴上的T300碳纤维环氧树脂复合材料层合壳为研究对象,首先应用拉格朗日方程建立线性动力学模型,通过瑞利-里茨法计算得到刚度矩阵和质量矩阵,求出模型的低阶固有频率值。再应用有限元软件ABAQUS,将数值模拟与理论计算所得到的固有频率进行对比,研究不同几何参数对固有频率和主振型等振动特性的影响。结果表明:不同几何参数对T300碳纤维环氧树脂复合材料层合壳固有频率和主振型均有较大影响,对实现机床主轴轻量化、保证刚度均有重要的指导意义。 相似文献
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基于模块化设计技术,开发了一种由直线电机驱动的高性能混联数控机床,主要由2-DOF并联主轴头和XY工作台两大功能模块组成。以该机床并联主轴模块为研究对象,基于边界元和刚度矩阵组集方法,建立了机床静刚度模型,并编制了刚度计算软件,由此计算得到机床主轴在整个工作空间内位置刚度和旋转刚度的分布。数值仿真表明:该机床具有较好的刚度特性,满足轻切削加工静刚度设计要求。 相似文献
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Meso车床是加工Meso量级(10-2-101mm)零件的机床,它是组成桌面式微型工厂的基础,它在设计上不同于一般的车床.文章介绍了一种Meso车床主轴系统的结构设计方案.并以此为例,对主轴部件的结构参数进行了计算,重点介绍了一种机床新主轴支承跨距理论值的数值计算方法.该方法代替了原来的查线图的方法,首先,构造主轴满足一定条件的挠度函数;然后,用主轴挠度函数的三次样条插值多项式近似代替原函数,进行数值微分,并编制、调试通过了相应的程序.该方法在工程上有一定实际应用价值. 相似文献
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《组合机床与自动化加工技术》2017,(8)
为了提高精密数控机床的加工精度,减少精密机床的热误差,文章提出了模糊神经网络径向热误差的建模方法。以数控加工中心关键点的温度和主轴径向的热变形量的关系为基础,应用模糊神经网络建模法,采用精密卧式加工中心主轴径向热误差的数据,对机床主轴热误差进行建模与预报。从数控机床主轴建模试验结果分析表明,模糊神经网络预测模型能够较为精准的对机床主轴径向热误差的做出预测,在实际应用中有利于提高机床的补偿精度,对数控机床热误差补偿提供参照。 相似文献
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CA6140机床主轴有限元分析 总被引:4,自引:0,他引:4
在机械加工中,CA6140机床的主轴在转动情况下,变形十分复杂,是造成工件尺寸误差和形状误差的主要原因之一,论文通过建立CA6140机床主轴的几何模型,采用有限元分析方法,分析了机床主轴在加工过程中的变形和应力,依据有限元分析结果,提出了减小机床加工误差的方法。 相似文献
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The thermal behavior of a machine tool is an important indicator for the grade of production accuracy and indirectly for the
market success. The load-dependent temperature distribution and the resulting deformation of the machine tool are influenced
by a variety of design and thermo-technical parameters. The main spindle of a machine tool is, without any doubt, the major
heat source within the machine structure. The object of the scientific investigation presented in this article is the development
of an approach to robust compensation of thermo-dependent machine tool deformations due to spindle load in consideration of
rough machining. The focus of the work concentrates on the identification of the model with the highest compensation performance.
The underlying concept for the compensation of thermo-dependent machine tool deformations is the indirect approach by using
the speed and the effective power of the main spindle for the calculation of the Tool Center Point (TCP) displacement. The
presented modeling approach requires the knowledge of the TCP displacement in X-, Y- and Z-direction depending on the speed
and the effective power of the main spindle. As a tool for modeling the thermo-dependent behavior of a milling machine, a
load test rig for repeatable, defined long-term loading of the main spindle has been developed. It simulates the cutting force
depending on the spindle speed and the torque and applies load to the main spindle. The spindle speed and the spindle effective
power can be taken directly from the numerical control of the machine tool. An important advantage of the presented compensation
method is the fact that it does not require any external sensors. The displacement of the TCP has to be measured, but only
during modeling. The relationship between the speed/power of the main spindle as a cause and the displacement of the TCP in
X-, Y- and Z-direction as an effect can be determined by a transfer function. This paper compares the compensation results
depending on the transfer function and identifies the model with the best compensation performance. The validation of the
compensation method is executed by using the example of two different speed and power spectra of the main spindle. 相似文献
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将模糊理论运用于再制造机床滑动导轨耐磨可靠性预测中,介绍了模糊可靠性分析过程,包括可靠度模型的建立、隶属函数的选择、磨损量分布参数的确定.通过实例阐述了可靠性预测过程和结果,以及与常规可靠性分析方法的不同.计算结果表明:在可靠性数据缺乏的情况下,运用此方法使计算结果更加符合实际,具有较好的工程应用价值. 相似文献
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M. Liang T. Yeap A. Hermansyah S. Rahmati 《International Journal of Machine Tools and Manufacture》2003,43(14):260
Developing a dedicated control system for each and every machining process or machine is costly and time-consuming. Such a practice has obviously undermined the usefulness of many current systems. This paper presents a fuzzy control system that can be used for different machining processes. This system consists of a basic fuzzy logic controller, a fuzzy rule base, and a tuning mechanism used to enhance the adaptability of the system. Industrial tests have been carried out for both end milling and turning processes. The control signal is spindle torque, readily available on many CNC machines. The test results show that the system performs well on both end milling and turning operations and can easily adapt to tool changes as well as workpiece material changes. 相似文献
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In view of the supposition that the modes of vibration of machine tool structure are separable, this paper discusses the mathematical expression of fuzzy dynamic response of a machine tool structure system that is under fuzzy parametric excitation and fuzzy external excitation using fuzzy mathematics analysis methods. It gives a pictorial diagram resolution of the fuzzy dynamic response of a machine tool structure that is under fuzzy parametric excitation and an explicit expression of the fuzzy dynamic response possibility distribution of a machine tool structure that is under fuzzy external excitation. 相似文献