共查询到20条相似文献,搜索用时 70 毫秒
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讨论了硼铸铁的组织和性能特点,综述了硼铸铁的发展过程及其在大型船舶柴油机气缸套中的应用情况。 相似文献
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对压铸镁合金冷却叶轮替代铝合金冷却叶轮进行了振动性能的分析。通过模态试验,得到了叶轮的固有频率和固有振型等主要模态参数,同时根据振幅衰减信号测得了镁合金AZ91D和铝合金A380的材料减振系数(SDC)。试验结果表明,镁合金对叶轮的模态参数改变不大,减振系数比铝合金的增加了10倍以上,极大地改善了叶片的振动性能,减小了叶轮的工作噪声。 相似文献
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船舶滑油系统的主要功能是为动力装置提供符合质量和数量要求的润滑油,以确保运动部件的正常润滑、冷却、防腐、清洁和传递动力等功能。在不同的运行工况下,滑油系统内部参数会发生显著变化,影响舰船系统的正常运行。因此,结合工程实际的使用需求和运行情况,采用MATLAB与Simulink对滑油系统进行仿真,以最大化其效益。主要从启动阶段、稳定阶段、停机阶段和故障阶段等多个方面进行仿真模拟,以最大程度地还原滑油系统的实际运行情况。结果表明:采用仿真技术可以有效模拟船舶滑油系统在各种工况下的运行情况,有助于优化系统设计和运行策略,以及最大化滑油系统的效益,保障舰船系统的正常运行。 相似文献
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柴油机电控喷油系统虚拟制造的研究 总被引:3,自引:0,他引:3
在集成统一的环境下,应用虚拟现实技术,人工智能技术和工程数据库技术等,运用虚拟制造的理论,建立了电控喷油系统虚拟制造的框架,提出了其主模型技术和综合可视化技术等关键技术并进行了研究,电控喷油系统虚拟制造的原型系统已部分实现。 相似文献
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发动机燃油喷射系统挺柱体的冷挤压成形加工技术研究 总被引:1,自引:0,他引:1
针对挺柱体零件的结构特点和16MnCr5钢的工艺特性,对原来的热挤压生产工艺进行了改进研究;开发出坯料的软化退火、正反复合冷挤压成形的新工艺,设计了简单、实用、可靠的模具结构.冷挤压成形加工的挺柱体坯件具有内孔尺寸精度高、尺寸一致性好以及内孔表面光洁、无毛刺等优点,其内孔型腔不再后续机械加工就能达到挺柱体零件的使用要求.生产实践表明,该冷挤压成形工艺高效、节能、节材、生产成本低,经济效益显著. 相似文献
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研究了由G20CrNi2MoA渗碳轴承钢制作的柴油机渗碳针阀体的回火特性。对该材料的化学成分、力学性能及显微组织进行了详细的检测,并研究制定了最佳的热处理工艺。在180~250 ℃不同温度下对针阀体试样进行回火处理,通过光学显微镜对针阀体座面及心部组织进行了分析,XRD检测了端面残奥含量,并用显微维氏硬度计对座面渗层及心部进行了硬度分析。结果表明,当回火温度为230 ℃时,G20CrNi2MoA钢针阀体的座面硬度可达740 HV(61.8 HRC),端面残奥体积分数为0.25%,能保证针阀体在230 ℃左右温度下具有良好的耐磨性和组织、尺寸的稳定性。试制出的针阀体寿命较长,能满足柴油机对针阀体的使用要求。 相似文献
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船用柴油机排气阀断裂原因分析 总被引:1,自引:0,他引:1
对断裂的某船用柴油机排气阀进行了化学成分和显微组织分析及硬度测试。结果表明,排气阀材质的化学成分和硬度都符合材料要求,但在排气阀内部发现少量氮化钛夹杂;断裂的排气阀断口具有典型的脆性断裂特征;排气阀在使用过程中,阀体表面氧化皮逐步脱落,氧化层向基体不均匀扩展,在阀杆表面形成多个裂纹源;阀杆机加工部位可能有残余应力存在进而导致阀体在加工位置断裂;另外,材料内部存在的夹杂对材料的性能有一定影响,使其未能完全满足排气阀高温腐蚀运行工况的要求。 相似文献
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R. Daniel Costley Mark E. Henderson Hitesh Patel E. William Jones Gary M. Boudreaux M. John Plodinec 《NDT & E International》2007,40(4):300-308
A non-intrusive technique has been developed which will detect an increase in pressure over ambient levels and alert workers of potential danger. Pressurization within the drum can be detected by measuring the frequency at which the drum lid vibrates; the natural frequencies increase as the pressure increases. It is shown that at high levels, the level of fill affects the frequency of the fundamental mode, but affects the higher modes to a much lesser degree. Thus, by measuring the frequencies of the fundamental and the first axisymmetric modes, the effect of fill level can be separated from pressurization. Analytical and experimental results are presented, along with suggestions for implementation. 相似文献
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Luis Ricardo Castro Pascal Viville Paul Lipinski 《International Journal of Machine Tools and Manufacture》2006,46(14):1707-1715
An original method for measuring dynamic forces using a commercial piezoelectric dynamometer is presented. This approach is based on the construction of a correction function taking into account the dynamic behavior of the mechanical environment: milling machine, measuring device and workpiece assembly. It allows measurement of the cutting forces for a large frequency domain exceeding the bandwidth of the piezoelectric dynamometer used. Through the located excitations, the complex equation of Transmissibility between the cutting forces and the dynamometer measurements is obtained. The methodology has been applied for a three-component commercial dynamometer fixed on a milling machine. It has been validated by means of the addition of controlled sinusoidal excitations. This method has applications in high-speed machining and in cutting processes involving instabilities. 相似文献
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Making an analysis for vibration modal and frequency response of the lathe spindle, respectively by using finite element method based on ANSYS and experiment of CA6140 type lathe in machining, and the calculation results are compared and analyzed, which verified the accuracy of ANSYS method. Numerical simulation and experimental results show that: Spindle in the first order and fifth order are prone to resonance, but did not reach resonance, the low order natural frequency have more effect than the high order natural frequency of the spindle vibration; by the experiments can conclude that the maximum vibration of the main shaft in the working state is mainly concentrated in the vicinity of its two ends, therefore, the improved bearing is an important way to reduce the vibration of the main shaft and ensure the machining accuracy, and the research results can provide a theoretical reference for the structural optimization design of the lathe. 相似文献