油液压缩性对凿岩台车翻转机构的影响研究

翻转机构是台车的重要部件，由于加工间隙，油液压缩等因素导致翻转机构在重忙碌 偏移时产生一个大的跳动，影响了台车钻臂的定位精度，文中分析了跳动产生的原因，提出了在定位过程中的处理方法及补偿准则，为钻臂在施工中的准确定位有指导作用。     

进油节流调速液压回路爬行现象的建模与仿真分析

本文通过对低速传动系统产生爬行现象原因的分析，建立了表征进油节流调速回路动态特性的非线性数学模型，进行了计算机仿真分析。     

低速走丝电火花线切割机ISO代码的后置处理

介绍了数控系统的译码过程及刀具半径补偿(包括放电间隙)在低速走丝电火花线切割机上的实现，详细讨论了刀具补偿时轨迹转接的分类及转接类型的判断。     

浅析影响汽车轮毂跳动的几个因素

汽车轮毂的跳动是一个非常重要的性能尺寸，它影响着汽车运行的平稳性及安全性。论文从理论上简单地分析影响轮毂跳动的五个环节，同时对影响轮毂跳动较大的环节进行试验分析，并运用统计过程控制的方法进行了验证。     

2024铝合金搅拌摩擦连接作用力幅值及周期性

利用八角环测力仪和高速摄像对2024铝合金搅拌摩擦连接过程作用力和搅拌头轴肩径向跳动量进行测量研究.结果表明,作用力具有周期振动的特性,通过试验证明了周期大小只与旋转速度有关,且为旋转速度的倒数.分析了作用力周期性振动的主要原因是连接过程中主轴的径向跳动和金属材料的流动,通过研究作用力幅值和搅拌头径向跳动量的关系,表明作用力幅值随搅拌头径向跳动量线性增加,搅拌头径向跳动是作用力产生周期振动的主因,同时,在搅拌头径向跳动量及其它工艺相同的情况下,作用力振幅会随着连接速度的增大而增大.     

快走丝线切割机导轮精度对工作精度的影响

线切割机在加工工件过程中，影响工作精度的机械因素有以下几种：1．机床的运动精度；2．机床的几何精度；3．走丝机构精度与走丝方式；4．主导轮部件的精度。在机床调试过程中，调试者比较注重前两项的精度调整，而容易忽视后两项对机床工作精度的影响，下面我就主导轮部件的精度对机床工作精度的影响作一下论述。主导轮部件的精度主要包括两项：l径向跳动，2轴向游动（串动）。1．径向跳动：是由于轴承精度和导轮零件精度决定的，在导轮旋转过程中出现的导轮半径方向上的跳动。其特点为无论导轮受力如何，只要导轮旋转即产生跳动。2．轴向…     

钛合金线性摩擦焊机头跳动对焊接质量的影响

简要介绍了钛合金线性摩擦焊过程中机头跳动的原因,着重分析了机头跳动对飞边形成及焊接界面的影响,并对由此产生的焊缝氧化物的分布特点进行了初步探讨,为线性摩擦焊机的设计与制造以及线性摩擦焊焊接工艺的制定提供了一定的试验依据.     

自动线加工零件的精度(14)

刀具调整装置的径向跳动。正如已经指出的那样,由于刀具调整装置各环节的制造误差,使紧固在主轴上的刀具悬臂轴线对主轴轴线有偏差。其结果是,刀具自由端在主轴回转时产生径向跳动2γ(图57)。刀具轴线相对主轴回转轴线的偏移量γ等于刀具端部径向跳动的一半: γ=f(e-1,e_2,e_3,e_4,e_s,ε) (65)式中e_l——主轴轴线相对于回转轴线的偏移量(为其跳动量的一半);e_2——由于接杆用紧固螺钉固定在主轴上产生了间隙,造成接杆配合直径轴线相对于主轴轴线的偏移;     

跳动公差与其他形位公差的关系及取代作用

跳动公差的应用方法较灵活，为避免在设计使用时出现标注不恰当或重复现象，结合图例，论述了跳动公差各项目之间及与其它形位公差项目之间的关系及取代作用。     

电液位置伺服系统低速运动的仿真研究

对典型电液马达位置伺服系统的低速运动进行了计算机数字仿真，对影响系统低速性能的诸种因素给予了分析，得出了几点有益的结论，它对改善系统低速的平稳运动具有一定的参考意义。     

Compensation of progressive radial run-out in face-milling by spindle speed variation

This paper investigates the use of spindle speed variation to compensate for progressive radial run-out in the face-milling process. Machine setup errors like spindle axis tilt, cutter axis tilt and cutter center offset result in radial and axial run-out on the inserts. Cutter center offset, in particular, results in progressive radial run-out on the inserts which can be compensated by continuously varying the spindle speed in a sinusoidal pattern. The amplitude and phase of the sinusoidal trajectory significantly influence the capability of this technique for run-out compensation. A method is proposed for selection of optimal values of the speed variation amplitude and phase based on the idea of matching the chip load pattern under variable speed machining conditions in the presence of progressive radial run-out with that of constant speed machining in the absence of any run-out. Experiments performed with optimal values of the speed variation parameters show a significant reduction in the cutting force component at the spindle frequency and a shift in the frequency content of cutting force from the harmonics of the spindle frequency to those of the tooth passing frequency. An industrial implementation strategy of the proposed scheme is also presented that integrates run-out estimation with its subsequent compensation.     

不平衡量对砂轮跳动影响的研究

本文利用激光位移传感器,在线采集砂轮基体外圆表面的振动信号,通过对信号的处理分析,得出砂轮基体的跳动值.在相同转速不同不平衡量的条件下,分析了砂轮基体的跳动值,结果表明:砂轮基体的跳动值随着不平衡量的增大而增大;在相同转速、相同不平衡量下,45#钢砂轮基体的跳动值比铝砂轮基体的跳动值平均约大0.05 μm.     

The effect of machining on the fatigue strength of a gamma titanium aluminide intertmetallic alloy

Experimental data is presented which compares the effect of grinding and high speed milling (HSM) on the fatigue strength of a gamma titanium aluminide intermetallic alloy. Results showed that HSM significantly increased fatigue strength by as much as 200 MPa over polished samples. Measurement and analysis of workpiece subsurface microhardness and microstructure indicated that the high run-out values correlated to high hardness and plastic deformation of the near surface lamellae.     

Modeling micro-end-milling operations. Part II: tool run-out

The effect of run-out is clearly noticed in micro-end-milling operations, while the same run-out creates negligible change at the cutting force profile of conventional end-milling operations. In this paper, the cutting force characteristics of micro-end-milling operations with tool run-out are investigated. An analytical cutting force model is developed for micro-end-milling operations with tool run-out. The proposed model has a compact set of expressions to be able to estimate the cutting force characteristics very quickly compared to the numerical approaches. The cutting forces of micro-end-milling operations simulated by the proposed model had good agreement with the experimental data.     

Analytical modeling and experimental validation of micro end-milling cutting forces considering edge radius and material strengthening effects

This paper presents a novel micro end-milling cutting forces prediction methodology including the edge radius, material strengthening, varying sliding friction coefficient and run-out together. A new iterative algorithm is proposed to evaluate the effective rake angle, shear angle and friction angle, which takes into account the effects of edge radius as well as varying sliding friction coefficient. A modified Johnson–Cook constitutive model is introduced to estimate the shear flow stress. This model considers not only the strain-hardening, strain-rate and temperature but also the material strengthening. Furthermore, a generalized algorithm is presented to calculate uncut chip thickness considering run-out. The cutting forces model is calibrated and validated by NAK80 steel, and the relevant micro slot end-milling experiments are carried out on a 3-axis ultra-precision micro-milling machine. The comparison of the predicted and measured cutting forces shows that the proposed model can provide very accurate predicted results. Finally, the effects of material strengthening, edge radius and cutting speed on the cutting forces are investigated by the proposed model and some conclusions are given as follows: (1) the material strengthening behavior has significant effect on micro end-milling process at the micron level. (2) Cutting forces predicted increase with the increase of edge radius. (3) Considering varying sliding friction coefficient can enhance the sensitivity of the predicted cutting forces to cutting speed.     

大方坯连铸机出坯系统的特点及设计要领

本文以大方坯连铸机典型的出坯线为依据,结合作者多年的设计和生产实践经验阐述了大方坯连铸机出坯系统的总体功能、设备特点、设备运转过程、设备布置及其设计原则等,供大方坯连铸设计工作者和大方坯连铸生产厂参考。     

A model for high carbon steel phase transformation and cooling behavior on run-out table of hot strip mill

A model was developed considering non-symmetric cooling in the thickness direction of strip on a run-out table of hot strip mill. In order to solve the one-dimensional transient heat transfer equation, including the heat evolved from phase transformation, a finite element method coupled with thermodynamic and kinetic analyses were employed. The heal capacity of each phase and the heat evolution due to phase transformation were obtained by thermodynamic analysis of the Fe-C-Mn system using a sublattice model. The phase transformation kinetics of high carbon steels was derived using continuous cooling experimente and mermodynamic analysis. By applying an inverse method, the heat transfer coefficients of the strips on the run-out table were determined from actual mill data under various cooling conditions. Using the developed model, the temperature-time variations of high carbon steels on the run-out table were calculated. The results calculated were in good agreement with the actual mill data. In addition, the quantitative phase evolution during cooling on the run-out table could also be predicted by the model. From this analysis, it was possible to design an optimum cooling pattern on the run-out table ensuring a desirable microstructure of high carbon steel and a stable cooling operation.     

曲轴径向圆跳动误差的工艺试验

通过工艺试验，研究了曲轴在加工过程中产生的径向圆跳动误差，并运用工艺链理论分析法分析了误差的种类和遗传方式。最后提出了减小曲轴主轴颈径向圆跳动误差的措施。     

在线淬火工艺对6005A合金挤压型材组织与性能的影响

采用正交试验和模拟试验的方法, 研究了在线淬火方式、淬火冷却速度及淬火延迟时间对6005A铝合金空心型材组织和性能的影响. 结果表明 提高在线淬火冷却强度比提高挤压温度和挤压速度对改善型材性能的效果更明显, 型材强度随淬火冷却速度的增大明显提高, 而延伸率并无明显降低; 在线精密水雾淬火可使型材性能满足车辆型材使用要求; 缩短在线淬火前型材在室温环境下的停留时间, 可以显著提高型材强度性能.     

基于数据融合的圆锥滚子端面侧摆自动检测

本文介绍的圆锥滚子端面侧摆自动检测系统，采用多周期检测和数据融合处理方法，能够有效滤除采样中的干扰信号、提高端面侧摆检测的准确性。实际使用结果表明，该系统符合圆锥滚子轴承检测规程，可以实现圆锥滚子端面侧摆自动检测和自动分拣。