共查询到13条相似文献,搜索用时 93 毫秒
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阐述分段注射/雕刻快速原型制造工艺的基本原理,论证该工艺的可行性.在此基础上,提出实现该工艺过程的技术需求,对实现该工艺的若干关键问题,包括材料选择、支撑去除、专用实验设备的设计制造及雕刻刀具的选择进行理论分析与实验研究. 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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Seung-hwan Choi Chunghwan Jeon Young June Chang 《Journal of Mechanical Science and Technology》2002,16(7):986-998
Flow and spray characteristics are critical factors that affect the performance and exhaust emissions of a direct injection
diesel engine. It is well known that the swirl control system is one of the useful ways to improve the fuel consumption and
emission reduction rate in a diesel engine. However, until now there have only been a few studies on the effect of flow on
spray. Because of this, the relationship between the flow pattern in the cylinder and its influence on the behavior of the
spray is in need of investigation. First, in-cylinder flow distributions for 4-valve cylinder head of Dl (Direct Injection)
Diesel engine were investigated under steady-state conditions for different SCV (Swirl Control Valve) opening angles using
a steady flow rig and 2-D LDV (Laser Doppler Velocimetry). It was found that swirl flow was more dominant than that of tumble
in the experimented engine. In addition, the in-cylinder flow was quantified in terms of swirl/tumble ratio and mean flow
coefficient. As the SCV opening angle was increased, high swirl ratios more than 3.0 were obtained in the case of SCV -70ΰ
and 90ΰ. Second, spray characteristics of the intermittent injection were investigated by a PDA (Phase Doppler Anemometer)
system. A Time Dividing Method (TDM) was used to analyze the microscopic spray characteristics. It was found that the atomization
characteristics such as velocity and SMD (Sauter Mean Diameter) of the spray were affected by the in-cylinder swirl ratio.
As a result, it was concluded that the swirl ratio improves atomization characteristics uniformly. 相似文献
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利用Moldflow分析软件,采用数值模拟的方法分析了料温、模具温度、注射时间、冷却时间和保压压力等工艺参数的变化对塑件产品翘曲的影响趋势及其原因。结果表明:对所选参数,保压压力对塑件翘曲的影响最为显著,且保压压力取注射压力的95%左右可使产品的翘曲量达到较小的程度;产品翘曲量随料温升高,注射时间减短而减小;冷却时间对翘曲量的影响甚微;模具温度对翘曲影响较为复杂。根据分析结果,优化了塑件的成型工艺参数,使得翘曲量进一步减小。 相似文献
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OPC技术在工业过程控制中的应用研究 总被引:1,自引:0,他引:1
OPC规范是由OPC基金会制定的一个工业标准,它规范了过程控制和自动化软件与工业现场设备之间的接口。简要介绍了OPC技术的产生,OPC标准的技术规范以及采用OPC规范设计系统的益处并概述了它在国内外的主要应用领域,对OPC技术在应用中的主要作用也有相应的分析。OPC代表了今后一段时间内过程控制系统通信标准的发展方向。 相似文献