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本文对异型薄壁弯折件冲切进行了可行性分析,在此基础上,设计了切断模,并对模具做了多组间隙值试验,获得了模具冲切间隙z与薄壁弯折件冲切时立筋刚度之间的相关性及用聚氨酯橡胶在结构上防止立筋失稳的措施。异型薄壁弯折件冲切是一种新的加工方法,它比铣削、砂轮切割提高工效5倍,本工艺对类似冲压件的切断有参考价值。 相似文献
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在汽车冲模中,冲切元件多属于易损件,给实际生产带来诸多不便和困难,造成生产周期长,生产成本高。为了解决这一问题,对冲切元件进行标准化是惟一可行的方法。我所根据多年经验和实践,采用国际标准优先数和优先数系,对冲切元件进行标准化,形成一系列多品种、多规格的冲切元件标准件。下面介绍几种常用的汽车冲模冲切元件的标准化概况。 相似文献
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正圆形垫圈是置于螺栓、螺钉或螺母的支撑面与联接零件表面之间,起着增大被联接零件接触表面面积、降低单位面积压力和保护被联接零件表面不被损坏作用的零件。飞机零部件间存在大量不同规格的钣金垫圈,其常规方法主要通过冲切模具,采用冲切方式加工获得。而在研制生产阶段,为满足飞机零部件各种改型设计,需要大量规格各异的垫圈,若采用常规的冲切工艺加工,需增加大量的垫圈冲切模具加工成本,模具的研制和生产周期也影 相似文献
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Balderas-López JA 《The Review of scientific instruments》2011,82(7):074905
The analytical solution for the one-dimensional heat diffusion problem for a two-layer system, in the Beer-Lambert model for light absorption, is shown to be useful for the implementation of a novel photopyroelectric (PPE) methodology, for the measurement of thermal and optical properties for pigments in liquid solution. The PPE signal, as a function of the sample's thickness, is used for this goal. Exponential decay for the PPE amplitude, followed by a constant PPE phase, for solutions at low dye concentration and an exponential decay for the PPE amplitude but a linear PPE phase behavior for the higher concentrated ones are shown and are, respectively, used for the measurement of the optical absorption coefficient and thermal diffusivity for liquid samples. These PPE phase behaviors also provide a criterion to decide on the corresponding limit for optical and thermal properties measurement. This PPE methodology was tested by measuring the optical absorption coefficient (at 658 nm) and thermal diffusivity for solution of methylene blue and copper sulfate in distilled water at various concentrations. Independent measurements of optical properties, using a commercial spectrometer, were done to compare with the corresponding ones obtained with this PPE methodology, finding very good agreement to each other. 相似文献
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D. H. Park S. S. Kang S. B. Park 《The International Journal of Advanced Manufacturing Technology》2002,20(1):31-38
In this paper a surface area calculation for non-axisymmetric deep drawing products of elliptical shape was constructed for
the design of blank shapes of deep drawing products by using an AutoLISP function in AutoCAD software. A computer-aided process
planning (CAPP) system for rotationally symmetric deep drawing products has been developed. In this study, a CAPP system for
non-axisymmetric deep drawing products of elliptical shape was constructed using process sequence design. The system developed
consists of four modules. The first is the recognition of shape module for recognising non-axisymmetric products. The second
is a 3D modelling module for calculating the surface area for non-axisymmetric products. The third is a blank design module
for creating an oval-shaped blank with an identical surface area. The fourth is a process planning module based on production
rules that play the most important role in an expert system for manufacturing. The production rules are generated and upgraded
by interviewing field engineers. The drawing coefficient, the punch and die radii for elliptical shape products are considered
as the main design parameters. The suitability of this system was verified by applying it to a real deep drawing product.
This surface area calculation and CAPP system should be very useful for reducing the lead-time for manufacturing and for improving
the accuracy of products. 相似文献
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A finite element formulation for the natural vibration analysis of tapered and pretwisted rotors has been presented. Numerical results for natural frequencies for various values of the geometric parameters and rotational speeds, have been computed for the case of rotors with and without pretwist. A Galerkin solution for the fundamental has also been worked out and has been used to provide a comparison for the finite element results. Charts for rapid estimation of the fundamental frequency parameter of tapered rotors, have been included. 相似文献
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本文讨论了机器人多手指抓取和适应性夹具设计的共同特点和理论基础。提出了刚体点接触下的约束锥和自由锥的概念,研究了两者的对偶性;推导了定位确定性条件,抓取封闭性条件,可达性和可分离性条件;严格定义了刚体点接触的约束度和自由度;建立了刚体在点接触约束下瞬时运动分析的几何理论,给出了封闭性和可达性的代数判别准则和计算机自动判别方法。为机器人抓取规划,适应性夹具设计提供了理论依据和实现方法。 相似文献
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基于MIC理论构建嵌入式装备控制领域建模语言的研究 总被引:1,自引:0,他引:1
现有的嵌入式系统开发成本高,采用通用的开发环境,应用领域的工程人员难以开发。由此,研究嵌入式系统面向装备控制的领域扩展技术。基于模型集成计算理论搭建嵌入式装备控制系统的元模型,解释成面向领域的图形化建模语言,使装备控制领域的工程人员能够对不同的嵌入式装备控制系统快速搭建模型。通过建立模型解释器,实现从应用系统模型到代码的映射。通过面向该领域软件构架的研究,探索面向系统的嵌入式组件设计方法。 相似文献
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亚临界和超临界汽轮机强度振动与寿命设计判据的研究 总被引:6,自引:0,他引:6
根据多年的科研成果提出了亚临界和超临界汽轮机部件的强度、振动与寿命的20个设计判据。给出了汽轮机的部件静强度、结构有限元分析、隔板刚度、低压缸刚度、汽轮机胀差、叶片动强度、整体围带叶片动强度、长叶片颤振、第一种调频叶片振动、第二种调频叶片振动、整圈连接叶片组振动、轴系临界转速、轴系油膜涡动的稳定性、不平衡响应、轴系扭振频率、轴系扭振应力、汽流激振、低周疲劳寿命、蠕变寿命和蠕变与低周疲劳交互作用下寿命等20个设计判据和这些设计判据的应用范围。使用这些设计判据,可以在设计阶段校核和分析汽轮机部件的强度、振动和寿命设计的安全性与可靠性,为大型汽轮机的研制和生产提供了科学的依据。 相似文献
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本文对PK制齿形作了扼要介绍,并阐述了PK制齿形的基准曲面的设计要点和替代曲面的共轭曲率值的修正量的确定原则。文中叙述了PK制齿形的各种切制方式以及PK制齿形计算卡的组成。文中还介绍了编写PK制齿形计算程序的源程序中所使用的标准过程的代码的含意,并列出了各种类型PK制齿形的计算程序的编组表。 相似文献
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