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1.
将常规的坐标测量设备通过增加转动的数控分度头,实现了鞋楦的全部断层图测量,为使楦的上下测量数据能按断层面合并,设计了基于共同断层面深度坐标的鞋楦上下面路径测量和断层扫描方法。 相似文献
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三坐标测量机是一种近些年发展起来的精密测量仪器,广泛应用于机械、电子和国防等各个领域,是现代机械产品质量控制与检测的重要测量设备。三坐标测量机检测同轴度具有高效率和高精度的特点,然而,在实际测量中,测量方法是影响测量结果的重要因素之一。结合实际情况分析比较了3种测量方法,分别为建立公共轴线法、改测直线度法及增大截面间距离法,指出了每种方法的测量特点及适合的测量环境,并通过实例简单分析了如何选取合适的测量方法,进而说明合理、有针对性的测量方法对获得准确、可靠的测量结果至关重要。 相似文献
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同轴度是机械加工中常见的一种形位公差,使用三坐标测量机进行同轴度测量时,有多种方法。部分同轴度在使用不同的测量方法进行测量时,测量结果之间存在较大的差别。文中通过对同轴度与其他形位公差的对比,提出多种测量方法,并对各类测量方法进行误差分析,明确应用范围,可以有效指导同轴度的三坐标测量。 相似文献
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同轴度是机械加工中常见的一种形位公差,使用三坐标测量机进行同轴度测量时,有多种方法。部分同轴度在使用不同的测量方法进行测量时,测量结果之间存在较大的差别。文中通过对同轴度与其他形位公差的对比,提出多种测量方法,并对各类测量方法进行误差分析,明确应用范围,可以有效指导同轴度的三坐标测量。 相似文献
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1问题的提出
加工中心和数控镗铣床与工具系统主要靠锥形刀柄来实现连接,其接口锥度是7:24。锥形刀柄作为一种精密加工工具,在整个切削过程中承担着将主轴的旋转运动及转矩传递给切削刀具的任务。即使是很微小的误差,也将直接影响到被加工工件的最终质量。由于铣床加工的刀柄尺寸多数是一次加工完成的,所以对这些尺寸的测量也就尤为重要。由此,精密刀柄的生产不仅要有先进的加工设备、娴熟的加工经验,更要有成熟的检验方法和测量手段。 相似文献
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随着世界范围内工业进程的不断深化,现代工业对机械装置等形状的要求日渐复杂,对测量的效率水平及精准程度要求也不断提高。本文主要介绍三坐标测量机测量叶型的方法,对三坐标测量机测量叶型的步骤作了介绍,对测量中各个环节相对需要关注的问题展开探讨。 相似文献
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正发动机缸盖气门阀座的加工是整个缸盖切削加工的关键工序,其加工精度的高低直接影响发动机的输出功率、油耗等重要指标,因此,缸盖作为汽车发动机核心的零部件之一,几乎是所有的发动机厂家必选的自制零件。产品对缸盖阀座加工过程中的阀座的角 相似文献
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王文书 《机械工人(冷加工)》2010,(12):60-61
同轴度检测是我们在测量工作中经常遇到的问题。实际使用三坐标测量同轴度公差工作中,由于测量方法不当,有时会出现测量结果误差大,重复性差的现象。 相似文献
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Bayesian approach for measuring EEPROM process capability based on the one-sided indices CPU and CPL
Chien-Wei Wu W. L. Pearn 《The International Journal of Advanced Manufacturing Technology》2006,31(1-2):135-144
The purpose of process capability analysis is to provide numerical measures on whether a process is capable of reproducing items meeting the manufacturing specifications. Capability analyses have received considerable recent research attention and increased usage in process assessments and purchasing decisions. Most existing research works on capability analysis focus on estimating and testing process capability based on the traditional distribution frequency approach. In this paper, we propose a Bayesian approach based on the indices CPU and CPL to measure EEPROM process capability, in which the specifications are one-sided rather than two-sided. We obtain the credible intervals of CPU and CPL and develop a Bayesian procedure for capability testing. The posterior probability p, for which the process under investigation is capable, is derived. The credible interval is a Bayesian analog of the classical lower confidence interval. A process satisfies the manufacturing capability requirements if all the points in the credible interval are greater than the pre-specified capability level w. To make this Bayesian procedure practical for in-plant applications, a real example of an EEPROM manufacturing process is investigated, demonstrating how the Bayesian procedure can be applied to actual data collected in the factories. 相似文献
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为了提高三坐标测量机(CMM)研发和整机精度设计水平,提出了一种基于区间层次分析法的CMM精度分配方法。首先建立CMM准刚体模型;基于CMM目标精度和行程范围,利用套索算法(LASSO)和正交三角分解对准刚体模型进行全参数、高精度求解,得到CMM的21项几何误差。然后根据CMM结构和运动方式,划分CMM整机的精度层次结构;利用区间层次分析法确定CMM关键零部件相对于几何误差的精度分配权重向量。利用CMM 21项几何误差和精度分配权重向量得到CMM关键零部件的精度分配结果。结果表明,针对目标精度为(4.5+L/400)μm的CMM,利用精度分配方法组装的样机精度达到(2.7+L/400)μm。因此所提出的CMM精度分配方法能够更精确的对CMM关键零部件的精度选取提供依据,提高整机精度,节约整机设计效率,降低研发成本。 相似文献
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Dr Chiu-Chi Wei Yu-Cheng Lee 《The International Journal of Advanced Manufacturing Technology》1995,10(6):416-421
An efficient approach has been developed for determining the process tolerances. This approach simplifies the traditional procedures of tolerance chart balancing and takes into account the capability of the process producing the workpiece. A mathematical model, based on the modified rooted tree chart, has been established. By using the model, the process tolerance can be obtained effectively and accurately without the effort of finding the additional tolerances. The work done previously by Ngoi is examined and several drawbacks are identified. A comparison between the results generated by the proposed method and by Ngoi is also made.Notation
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additional tolerance to be added
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jth functional relationship betweent
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andd
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the number of blueprint specifications
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the number of operations
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the failure rate
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estimated standard deviation ofith operation
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initial tolerance
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blueprint tolerance
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upper limit of process tolerance
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process tolerance for operationi
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standardised process tolerance
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weighting value
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the minimum value amongx
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基于高斯光学齐次坐标变换的光机装调 总被引:1,自引:1,他引:0
高性能光学系统装调的调整量与光机结构设计相关,而装调所用参考坐标系往往与光学设计所用的坐标系不同。为了精确描述调整量对高斯像位置的影响,本文在基准坐标系下建立了引入装调误差量的高斯光学齐次坐标变换模型。针对具体的光机结构,建立了高斯像像旋和离焦对调整变量的函数,据此计算小的结构变化导致的离轴三反望远物镜高斯像面的移动,结果显示其与光学设计软件对最佳像面位置优化结果的相对差小于4%。利用方差合成方法建立线性规划模型,对17个装调变量做了最宽松的误差分配方案。用Monte Carlo法验证了分配方案,结果表明,该方案在±300μm调焦能力下满足各视场±10μm的焦深要求。本文的方法忽略了复杂、微小像差的影响,适用于含多个已做内部精装的光学组件或平面反射镜的复杂成像光学系统的装调。 相似文献
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介绍了一种在坐标测量机CAI系统中确定机械零件表面上测量点和测量路径自动生成的方法,该方法提高了测量的自动化,有利于测量、设计和制造过程的相集成。 相似文献
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虚拟装配操作中基于语义的推理方法研究 总被引:1,自引:1,他引:0
在虚拟装配中,基于几何约束的交互装配操作与实际的工程约束不完全相符,导致与设计装配操作意图不完全一致,且装配操作不够自然、效率不高.为此,提出基于装配任务层次和装配语义识别的虚拟装配操作方法.通过装配语义的生成、识别、确认和解算,将虚拟装配系统对装配关系的识别,从约束层次提高到装配任务层次.在汽车发动机零部件的虚拟装配中的应用表明:该方法能够很好地捕捉虚拟装配过程中的用户交互意图,通过用户能够在虚拟环境中方便、准确地进行装配,使装配效率得到明显提升. 相似文献
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Accredited laboratories are required to perform measurements in accordance with the highest standards of quality and reliability. The pursuit of this is associated with considerable effort and commitment on the part of each laboratory that wants to find recognition in the measurement services market. Undoubtedly, the laboratory needs to possess outstanding technical capability, participate in proficiency testing and inter-laboratory comparisons, and follow reliable and validated calibration methods. This paper presents a validation procedure using the specially developed universal algorithm which offers specific, step-by-step validation of coordinate measurement methods. The paper first discusses the selection of validation methods, and then proceeds to discuss the choice of a sophisticated multi-feature check and calibration measurements performed in chosen laboratory. The final part of this publication is devoted to the development of a validation model used for verifying measurement methods. 相似文献