共查询到20条相似文献,搜索用时 62 毫秒
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显微注射过程中,细胞的变形量和受力大小对注射成功率有直接影响,为提高自动化注射系统的可靠性,需对细胞力学特性进行研究。基于膜理论建立了细胞的接触模型,针对静态膜理论模型无法描述细胞的受力和变形关系随穿刺速度及加速度变化的问题,提出动态修正细胞膜材料参数的方法。采用不同的穿刺速度和加速度对分形期的斑马鱼卵进行穿刺实验,导出了细胞膜的动态接触经验模型,较好地表征不同穿刺条件下细胞膜的变刚度现象,为控制系统的设计提供参考。 相似文献
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为实现细胞工程中细胞显微注射的要求,提出了一种用X—Y—Z三坐标微位移台来完成细胞微量注射微动平台定位和注射的装置,X—Y—Z三坐标微位移台微量注射装置的定位和注射动作全部由直流步进电机驱动,步进电机在高细分驱动器驱动下,步进精度达0.004μm,滑台的定位精度达0.3μm,而生殖细胞尺寸通常处于1~100μm范围,基本满足细胞显微操作精度要求,普通国产三轴控制器即可实现所需控制功能,和目前国内外的其他细胞微量注射装置相比,其主要特点是定位精度和注射精度都比较高、成本低。 相似文献
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根据显微注射流程要求,介绍一种基于单片机89S52的微注射器控制系统的设计.论述了控制系统气路工作原理、硬件电路设计和软件的设计思想.该系统可以完成微注射所需各种工作,并通过上下微机通信传送注射压力、补偿压力、注射时间,用于实验分析比较. 相似文献
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提出了利用压电陶瓷的逆压电特性进行显微注射的设计方法,完成了显微注射仪的结构设计。利用计算机编制交替的驱动信号程序,通过压电陶瓷驱动器驱动电源对压电陶瓷进行驱动,压电陶瓷驱动器通过电致伸缩及对导杆的交替箝握实现显微注射仪的微米级步进运动,可精确控制显微注射时注射针的穿刺位置,有效提高显微注射成功率。 相似文献
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穿孔机出口台二段是热轧穿孔机组的重要辅助设备,直接影响到穿孔后毛管的质量及其生产效率。简要介绍了韩国Φ180mm穿孔机出口台二段的结构及其特点等。 相似文献
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采用PLC控制,步进电机分度,实现自动分度、自动冲孔、送料及退料的轴承保持架自动冲孔机,解决了传统的轴承保持架侧孔冲孔模机械方式分度,分度精度低及生产效率低等问题. 相似文献
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分析了圆筒类零件的冲裁工艺特性,论述了筒类零件侧向孔自动分度冲孔模结构特点和工作原理。通过棘轮棘爪机构带动主轴转过一个分度值,然后依靠分度盘、棘轮机构使主轴准确定位后再进行冲孔。结果使得所冲侧孔分度均匀。累积误差小,且模具结构简单、操作方便,保证了产品的品质,提高了生产效率。 相似文献
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通过对冲压制件修边工艺参数和修边模具结构设计两方面的总结讨论,阐述了汽车冲压制件修边工艺及模具设计的基本要点及在设计过程中采用的经验方法,为冲压制件修边工艺的排布及修边模的设计提供参考。 相似文献
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通过对筐形保持架冲孔模花键杆、花键套的改进,使保持架等分孔质量稳定,延长工装寿命,降低生产成本。 相似文献
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Finite element simulation of the punchless piercing process with Lemaitre damage model 总被引:1,自引:0,他引:1
Sang Wook Lee Farhang Pourboghrat 《International Journal of Mechanical Sciences》2005,47(11):1756-1768
The punchless piercing is a process that uses highly pressurized fluid instead of the conventional punch to make holes into the sheet metal. This process has many advantages over the conventional method for piercing various shaped holes into very thin strips of metal, composite, etc. An important cost advantage comes from not having to use a punch. Another important advantage comes from the top quality of pierced holes produced by punchless piercing, as no secondary finishing process will be needed for removing burrs typically found in conventional cutting processes.The ABAQUS/Explicit FEM code coupled with Lemaitre damage model has been used to more precisely characterize the punchless piercing process of a copper sheet. The formulation adopted for this purpose uses an established and efficient stress integration algorithm and development of a user material subroutine (VUMAT).For verification, the computed results have been compared with those of the experimental results in the literature and shown to be in good agreement with each other.The results obtained from this work are expected to be of significant interest to automotive and aerospace industries interested in using the punchless piercing process. 相似文献
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J.C. Choi C. Kim J. H. Yoon 《The International Journal of Advanced Manufacturing Technology》2000,16(9):624-634
This paper describes the development of computer-aided design of irregular-shaped sheet metal products and 32LD PLCC lead
frames and semiconductors, requiring very precise piercing operations for progressive working. The approach to the CAD system
is based on knowledge-based rules. Knowledge for the CAD system is formulated from plasticity theories, experimental results,
and the empirical knowledge of field experts. This system has been written in AutoLISP using AutoCAD on a personal computer
and the I-DEAS drafting programming language on the I-DEAS master series drafting with an HP 9000/715(64) workstation. Transference
of data between Auto-CAD and I-DEAS master series drafting is accomplished using DXF and IGES methods. This system is composed
of five main modules, which are input and shape treatment, production feasibility check, strip-layout, data-conversion, and
die-layout modules. Based on knowledge-based rules, the system is designed by considering several factors, such as V-notches,
dimple, pad chamfer, spank, cavity punch, camber, coined area, cross bow, material and thickness of product, complexities
of blank geometry and punch profile, and availability of presses. As forming processes and the die design system using 2D
geometry recognition are integrated with the technology of process planning, die design, and CAE analysis, the standardisation
of die parts for lead frames requiring a high precision piercing process is possible. The die-layout drawing generated by
the die-layout module is displayed in graphic form. Results obtained for each module provide help to the designer and the
manufacturer of lead frames for semiconductors. 相似文献
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三辊联合穿轧机是一种新型斜轧机,采用组合孔型轧辊和顶头,在一个道次内完成钢管的穿孔、轧制和均整。基于某厂现有轧机,经过多次工艺试验,将液压同步缸应用于无缝钢管三辊穿轧机同步压下系统,并对该同步压下系统的可行性进行了仿真分析。该项研究对轧机液压控制系统设计,以及提高最终产品的质量和钢材成材率具有重要意义。 相似文献