快速偏心夹具的设计与应用

工件的装夹速度是夹具设计研究中的一个重要课题.分析了现有生产过程中使用的传统夹具和新型夹具的结构和特点.设计了快速偏心夹具,由偏心机构和推拉杆组成,偏心机构对工件施加夹紧力,推拉杆为适应于不同尺寸工件的频繁更换而设计,满足了夹紧力技术要求,达到了快速夹紧工件的目的.此夹具结构简单、适用工件范围广、夹紧可靠、生产率高.     

抗振偏心夹紧结构初探

偏心夹紧结构以其动作迅速的特点在各种夹紧结构中独树一帜,但也有其一些局限性,限制了它在夹紧结构中的广泛应用,表现为①抗振性差,仅适用于切削过程中振动不大的场合;②夹紧行程受偏心距限制,仅适用于工件被夹压表面尺寸公差较小的场合.我们在长期的机床夹具设计实践中体会到,只要选用一种抗振性好的结构作为它的辅助锁紧装置,那么偏心夹紧结构的应用将会大大扩展.对于该附加锁紧装置,除要求它锁紧可靠外,锁紧操作一定要简单,结构也不宜复杂,否则便会使偏心夹紧结构动作迅速的优点消失,而造成整个结构舍简求繁.     

偏心轮直接作用单侧水平夹紧双圆柱定位钻模

介绍了一种结构简单、制造工艺性好的以偏心轮为直接夹紧元件的单侧水平夹紧双圆柱定位钻模。给出了该钻模定位误差的一般计算公式和微分近似计算公式。该夹具适用于加工在轴向上定位部位与夹紧部位重合的轴、销、套类零件的径向孔。     

套类零件自定心夹具的研究

介绍了一种适用于在镗床上进行套类零件加工的自定心夹具,该结构能自动消除定位间隙,定位精度高,夹紧刚性好,能有效地提高套类零件的加工精度。     

偏心柱夹紧机构

夹具设计中,常见偏心轮夹紧机构,但其结构较复杂。经实践我们采用如图所示偏心柱夹紧机构,结构简单,刚性好,夹紧力可靠。特别适用于小零件的定位后夹紧,松(?)夹迅速,钻、铣可行,磨损后易更换。     

半圆键内胀心轴

介绍一种以圆柱面定位,靠半圆键夹紧的内夹紧心轴,该心轴可用在曲柄车夹具以及钻、攻曲柄螺纹孔的成组车夹具中,又能固定在两项尖间,因而特别适用于精车和磨削加工.     

新颖钻模夹具及其定位误差的计算方法

介绍一种结构简单、制造工艺性好的单侧斜向夹紧双圆柱定位钻模，给出了该钻模定位误差的一般计算公式和微分近似计算公式。该夹具适用于加工较短的轴、销、套类零件的径向孔，其原理也可用于设计铣削轴套类零件键槽和平面夹具。     

单侧斜向夹紧双圆柱定位钻模

介绍了一种结构简单、制造工艺性好的单侧斜向夹紧双圆柱定位钻模,给出了该钻模定位误差的一般计算公式和微分近似计算公式。该夹具适用于加工较短的轴、销、套类零件径向孔,其原理也可移植用于设计铣削轴承类零件键槽和平面的夹具。     

活塞杆斜孔回转式钻床夹具

通过分析活塞杆上斜孔的加工工艺、结构特点,进行钻孔夹具设计,文中着重阐述了夹具的工作过程,以及定位方案、夹紧方式、定位误差和夹紧力的确定.实践证明,该夹具操作方便,生产效率高.     

双滚道面齿轮的磨齿夹具

本文介绍一种定位精度高、夹紧可靠、使用方便灵活、结构新颖的磨齿夹具。适用于汽车变速器、发动器上具有双滚道面内孔结构的齿轮，亦可作为检验夹具使用，具有广泛的推广应用价值。     

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。     

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。     

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.     

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。     

基于多目标非支配解提取法的电力系统无功优化

针对传统的电力系统多目标粒子群优化算法采用权重系数法将多目标转化为单目标,从而忽视了各目标函数间的竞争关系这一问题,提出将非支配解提取法运用到电力系统多目标无功优化中,并设定了一套提取规则,以电力系统中的有功网损、电压偏差和电压稳定裕度为目标,使目标在充分竞争的情况下得出Pareto最优解,利用IEEE-14节点系统对多目标非支配解提取法的电力系统无功优化进行了仿真测试。研究结果表明,该算法一次运行可以得出多组非支配解,既有偏向单个目标的解也有兼顾所有目标的解,克服了权重系数法的盲目性和单一性,可使电力决策者根据实际问题选择最优解,具有较好的灵活性与多样性。     

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.     

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%.