气动减压阀的标准及检验方法研究

介绍了气动减压阀国内外标准的概况,通过对气动减压阀的国内外相关标准研究,找出各标准间的差异,包括标准适用范围和测试项目的差别,主要特性的测试回路、检测方法和表述方法的区别,并指出了减压阀可靠性标准ISO 19973-4变更前后的技术变化。选取国内某厂家生产的精密减压阀作为实例,按照ISO 6953-2的方法要求,测试了分辨率和重复精度等主要特性。     

高效节能的减压阀流量特性测量方法的仿真与实验研究

介绍了一种高效节能的减压阀流量特性测量新方法--基于等温容器的充放气法,针对内部先导型精密减压阀IR2020对测试系统进行建模仿真和实验研究.研究结果表明该方法具有较高的精度,且和传统法相比具有测试时间短、测量效率高、耗气量少等特点.     

基于AMESim的先导式精密减压阀的建模与仿真研究

针对减压阀的实用性和特殊性问题,首先对国内外液压研究现状进行了总结,并以三通先导精密减压阀为研究对象,通过绘制其CAD原理图,分析其实际工作原理并建立了静态特性分析数学模型。同时,借助AMESim模型进行仿真验证,利用仿真模型对大流量精密减压阀的结构参数和特性进行较全面的仿真研究,优化了常泄气口直径。仿真结果表明,随着常泄气口增大,将会使进气先导阀的开口和进气流量也随之增加,从而使先导腔在更短时间内达到饱和状态,且AMESim具有建模简便、运算快捷等优点,能够更大程度上节约实验和设计成本。     

精密减压阀的研制

作为压力调节与保持压力稳定的元件—减压阀是任何气路系统必不可少的。国内普通减压阀的生产和使用已很广泛,但在输出压力调节精度高的场合,特别是工业过程、检验程序的控制与分析,检测仪表和气动自动装置等要求保持压力恒定的地方,就必须使用精密减压阀。国内目前现有的定值器、稳压器等输出压力一般在0.15MPa 左右,不能满足需较高输出压力场合的使用,为此我所与上海气动元件厂共同进行了研制。一、结构及其特点精密减压阀由调压、比较、放大、反馈、稳压等部分组成。见图1。阀芯工作状态时为虚线位置。它是在内部先导式减压阀的基础上引入喷嘴一挡板放大机构。利用喷嘴挡板的位移引起力的放大,使膜片两侧受力达到平衡,来维持输出压力的稳定。由于喷嘴挡板具有高灵敏度,因而精密型减压阀的输出压力精度     

小型、低压、高精密减压阀的结构设计及稳态特性计算

该文对一种军民两用的小型、低压、高精密减压阀的结构设计进行了总结,并对静态特性进行了分析计算。     

简讯

由上海气动元件厂和无锡气动技术研究所共同承担的国家重大技术开发项目“精密过滤元件”、“精密排污器”、“精密减压阀”和“二次雾化器”四个科研项目,于88年7月1日至2日在无锡通过鉴定。     

四项国家七五重大开发项目试制成功

由上海气动元件厂和无锡气动技术研究所联合承担设计制造的国家七·五重大开发项目:精密自动排污器;精密过滤元件;二次雾化器;精密减压阀四个项目,日前在无锡通过部级鉴定。鉴定会认为:精密自动排污器采用了自动浮子式结构,主要性能达到日本同类产品水平。精密过滤元件采用了先进的过滤机理和高级过滤材料,主要性能达到日本CKD公司同类产品水平。二次雾化器二次雾     

反向式气体减压阀静态特性仿真分析

采用AMESim软件进行了反向式减压阀静态特性研究。分析了改变设计流量Q、刀锋直径d、敏感活塞面积Am和弹簧有效刚度Ke等参数对反向减压阀静态特性的影响,并通过减压阀性能试验进行验证,为减压阀研制提供了合理可行的理论依据。     

基于AMESim的高压气动减压阀的稳定特性

针对氢能源汽车中气动减压阀高压化减压时减压阀稳定性下降的现象,对一种带有先导稳定流量器的高压气动减压阀进行特性研究。建立高压气动减压阀的AMESim仿真模型,仿真分析了其压力、流量特性、高压气动减压阀先导阀弹簧刚度、先导稳定流量器活塞阻尼孔、高压气动减压阀主阀弹簧刚度、主阀出口腔等参数对高压气动减压阀稳定性的影响。研究结果表明,带有先导稳定流量器的高压气动减压阀在高压化减压时,其出口压力稳定,压力振荡小,动态响应快。同时,适当地增大复位弹簧刚度,先导稳定流量器活塞阻尼孔,出口腔容积的增大,可提高阀的输出压力的稳定性和快速性。     

基于AMESim的CNG双级减压阀动态特性的研究

减压阀出口压力的稳定性是实现双燃料发动机天然气流量稳定供给的基础。基于某款CNG双级减压阀的结构及工作原理,应用AMESim数值仿真软件构建减压阀各个腔体仿真分析模型,研究减压阀压力流量特性及其动态特性;通过构建的减压阀工作测试平台,对比试验验证了仿真模型的正确性;通过改变仿真模型中各个参数的数值,研究各结构参数对减压阀动态特性的影响规律,为该减压阀的结构设计和参数优化提供理论。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.     

CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.