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数控机床作为现代制造业的核心装备之一,直接反映国家的整体技术和经济水平。分别讨论了数控机床满负荷切削、曲线切削、标准件切削和刚性攻丝实验,用于考核评价机床的负荷能力、动态性能、切削精度和螺纹加工能力,对于企业优化机床的切削性能、提高机械产品的加工质量具有实际参考价值。 相似文献
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《组合机床与自动化加工技术》2017,(5)
在重型数控机床产业,伺服惯量匹配对进给伺服系统的动态性能有着非常重要的影响,文章搭建了数控机床进给伺服系统通用的全闭环仿真模型,以GMC1600H/2五坐标横梁移动龙门加工中心Y、Z轴为研究对象,分析了时域和频域下惯量比对单轴系统性能的影响以及Y、Z轴联动时不同惯量比对直线轨迹和圆形轨迹轮廓误差的影响,给出了直线加工和圆弧加工两种加工形式下较优的惯量比范围,并说明了在超过一定惯量比范围后,系统轮廓误差会呈现明显的波动,为数控机床伺服驱动中的惯量匹配提供了理论依据。 相似文献
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热误差作为影响机床加工精度的重要因素之一,严重制约着机床加工精度的提高。而主轴是数控机床的关键功能部件,对其进行热特性研究对提高机床的加工精度具有重要的意义。将同一类型、不同使用年限的机床主轴温度值和热变形值作为评价指标,建立数控机床主轴的神经网络热评价模型;针对BP神经网络易陷入局部最优值、收敛速度慢等问题,采用粒子群优化(PSO)算法优化加权朴素贝叶斯(WNB)的初始权值,获取权值全局最优解,构建了粒子群优化加权朴素贝叶斯机床主轴热评价模型,实现对机床主轴热特性的评价。MATLAB仿真结果表明:PSO-WNB模型精度为941%,收敛速度快,预测精度高,优于BP神经网络,为数控机床热特性评价提供了新思路。 相似文献
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《组合机床与自动化加工技术》2021,(8)
刀尖跟随轨迹精度作为评价五轴联动数控机床RTCP功能重要的动态性能指标之一,直接影响零件加工精度。为了准确评价五轴机床动态性能,进行刀尖跟随轨迹测量方法的研究,在测量的基础上,建立测量误差模型,分析其测量误差影响因素,进行测量不确定度评定,并以一台商用转台加摆头式(RTTTR型)五轴联动数控机床为实验对象开展刀尖跟随轨迹精度动态测量试验,确定了各不确定度因素对测量结果的影响关系。试验结果表明,该方法可有效地评价五轴联动数控机床刀尖轨迹精度,并为提高测量精度提供方向指导意见。 相似文献
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影响经济型数控机床加工精度的因素分析 总被引:6,自引:0,他引:6
如何提高经济型数控机床加工精度是机床数控改造的关键问题之一。本文分析了步进电机驱动的经济型数控机床加工精度影响因素,提出了提高加工精度的途径及补偿方法。 相似文献
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介绍了“一次过加工”技术的概念,分析了超高速切削、磨削,电解、电火花、精锻、精铸的“一次过加工”技术特点,对其适用场合、相互关系和应用前景做了较为详细的阐述。 相似文献
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Analytical model to determine the critical feed per edge for ductile-brittle transition in milling process of brittle materials 总被引:2,自引:0,他引:2
Muhammad Arif 《International Journal of Machine Tools and Manufacture》2011,51(3):170-181
Brittle materials like glass are considered difficult-to-machine because of their high tendency towards brittle fracture during machining. The technological challenge in machining such brittle materials is to achieve material removal by plastic deformation rather than characteristic brittle fracture. In ductile mode machining, the material is removed predominantly by plastic deformation and any cracks produced due to possible fracture in the cutting zone are prevented from extending into the machined surface. This is achieved by selecting an appropriate cutting tool and suitable machining parameters. In ductile machining by milling process, fracture induced cracks are diverted away from final machined surface by selecting a suitable feed per edge less than a critical threshold value. Hence determination of critical feed per edge is of paramount importance to achieve ductile mode machining by milling process. This paper presents an analytical model based on fracture mechanics principles to predict the critical feed per edge in milling process of glass. The size and orientation of cracks originating from brittle fracture during machining have been quantified by using indentation test results and the critical value of feed per edge has been determined analytically as a function of intrinsic materials properties governing brittle fracture and plastic deformation. Furthermore, an equivalent tool included angle has been suggested for machining operation as against the indenter included angle to correlate the indentation and machining test results with improved degree of accuracy. Experimental results validated the proposed model fairly accurately. It has been established that if the longest cracks oriented in radial direction to the cutting edge trajectory are prevented from reaching the final machined surface by selecting a feed per edge less than or equal to a critical value, a crack-free machined surface can be achieved. 相似文献
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