分度凸轮传动装置系列化有关设计准则的探讨

对凸轮分度机构系列化设计进行了探讨。指出了其几何尺寸系列化的特点,讨论了凸轮机构的主要失效形式,建立了相应的设计准则,并推导出计算方法。其分析理论亦可分为其它复杂凸轮机构设计所借鉴。     

Effects of lubricants on friction and wear of Ti(CN)/1045 steel sliding pairs

The friction and wear properties of Ti(CN)/1045 steel rubbing pairs were investigated under dry and lubricated conditions by using a pin-on-disk tribometer. The selected speed range was 0.8 to 3.2 m/s and the load range was 58.8 to 235.2 N. Distilled water and a mineral oil (no additives) were used for lubrication, respectively. The wear of Ti(CN) ceramic under dry conditions was caused mainly by adhesion between the rubbing surfaces and the microfracture of Ti(CN). With the load and speed increasing, the adhesion and diffusion between rubbing surfaces increased and resulted in wear increasement of Ti(CN). Because of the brittleness of ceramics, the microfracture wear of Ti(CN) increased rapidly when the load was raised to some high values. The lubricating and cooling effects of the lubricants could improve the frict on and wear. Compared with water, oil was much better in improving the tribological properties. The analysis results obtained from XPS and AES examinations showed that ferrous oxide was produced on the wear scars, which could reduce the adhesion between the rubbing surfaces to some extent. The lubricating effects of the oil under boundary lubrication conditions were attributed to the formation of carbon films on the rubbing surfaces.     

速度及加速度曲线的不连续性对凸轮机构的影响

本文论证了若给定运动的速度曲线具有不同连续点时凸轮的实际轮廓,将产生交 或跳跃间断。这样,在不连续附近就不能实现给定的运动。     

数值计算方法在凸轮设计与优化中的应用

介绍了数值计算方法中的样条函数插值法；样条函数在凸轮设计中的应用及与其它插值法相比较的优点；利用Visunl C＋＋、TC、ObjectARX编写了凸轮廓线的插值与仿真程序和实现在AutoCAD中自动生成图纸；用印后设备中配页机的三个凸轮数据对程序进行了验证，得到了符合设计要求的凸轮廓线数据。     

The composition of lubricant-derived surface layers formed in a lubricated cam/tappet contact II. Effects of adding overbased detergent and dispersant to a simple ZDTP solution

The surface films formed by a set of oils of related additive chemistry, but with differing detergent and dispersant contents, have been chemically characterized using a combination of surface analysis techniques. The films were formed in a cam/tappet friction apparatus with a direct acting bucket tappet geometry. In the absence of overbased detergent, the amorphous films were composed essentially of inorganic zinc phosphates formed by the ZDTP anti-wear additive, and evidence of higher molecular weight phosphates (e.g. metaphosphates) was found. Adding overbased detergent and dispersant resulted in partial replacement of zinc by the detergent metal and loss of the higher molecular weight phosphates in favour of ortho- and pyro-phosphates.     

间歇分度凸轮机构的凸轮曲线图谱研究

凸轮曲线设计是决定间歇分度凸轮机构性能的核心问题.根据参数的无因次化对各种凸轮曲线进行程序开发,绘制出常用凸轮曲线的运动规律曲线.为他人或企业研究间歇分度凸轮提供了参考,避免了设计人员的重复设计,缩短了设计周期.     

凸轮机构的谐综合

提出了用有限项的谐函数作为凸轮机构一个工作循环的位移函数来设计凸轮廓线。从而主动避免高阶分量可能激发的共振。还讨论了确定谐函数各项系数的优化方法 ,并通过实验 ,对传统设计和该方法设计的凸轮动力特性进行了对比 ,证明了该设计方法的优点     

模糊综合决策在凸轮机构设计中的应用

介绍了在凸轮机构设计中,运用模糊综合决策的方法进行凸轮机构类型的选择,从动件运动规律的选择和凸轮机构材料的选择。并由此指出,在机械设计的方案确定、参数选择中,模糊综合决策是一种切实可行的方法。     

基于AutoCAD的凸轮外形轮廓曲线的设计方法

介绍了在AutoCAD环境下凸轮外形轮廓曲线设计的方法,解决了几何法绘制凸轮外形轮廓曲线误差较大的问题.运用本文介绍的方法能够极大地提高凸轮外形轮廓曲线的设计精度和效率.     

BP神经网络在凸轮型线拟合中的应用研究

介绍了BP网络的原理、算法,并用凸轮对应角度下的理论升程值对BP网络进行训练,然后输出拟合值.经过分析,证明采用BP神经网络拟合凸轮型线,能够实现任意角度下对应理论升程值的快捷计算.     

基于CAXA软件平台的凸轮机构CAD系统开发研究

基于CAXA—EBV2软件平台 ,采用面向对象的程序设计方法 ,以VC + + 6 0为编程语言 ,开发出凸轮CAD软件模块。该模块扩大了CAXA软件的功能 ,实用性强 ,操作简便 ,可简化凸轮机构的设计过程 ,提高设计精度     

Visual Basic在凸轮轮廓设计与制造中的应用

介绍用VisualBasic语言开发凸轮轮廓设计与制造软件的关键技术与方法。     

三构件凸轮导引机构的设计

本文提出了凸和为固定构件的三构件凸轮导引机构的优化设计方法,针对不同的设计阶段和设计参数,采用相应的优化目标,实现了整体优化的目的。     

基于Simulink的凸轮机构动力学仿真研究

提出了运用仿真技术对凸轮机构进行动力学分析的方法,介绍了在simulink下的凸轮机构仿真过程。通过一实例得出:该方法具有运算简便、精度高、速度快等特点。同时,通过对仿真参数的修改,可进行凸轮机构的参数优化。在凸轮机构设计过程中,可大幅提高其设计精度和效率。     

Influence of spot-weld failure on crushing of thin-walled structural sections

Structural effectiveness differences have been observed in a recent study on the progressive axial collapse of thin-walled structural sections when made from different classes of steels (mild steel, interstitial-free rephosphorized high-strength steel and high-strength low-alloyed steel). A higher effectiveness was observed for spot-welded top-hat sections made from a mild steel than for similar sections made from a high-strength steel. For square sections, the structural effectiveness was not affected by the steel classes. It is anticipated that this observation applies not only for spot-welded top-hat and square sections, but for other joined and unjoined thin-walled structures as well.

The part and full failure of spot-welds, during the axial collapse of the thin-walled structural sections, is one possible explanation for the above inconsistency. This is investigated experimentally in this article using peel tests on spot-weld samples under quasi-static and dynamic conditions. Despite having a lower material strength, the mild steel spot-weld samples exhibited a higher peak force and similar energy absorption during failure when compared with a high-strength steel, both under quasi-static and dynamic loadings.

The potential contribution to the mean crushing force during progressive axial collapse is estimated from the experimental results and comparisons are made with deformed thin-walled structural sections from a recent experimental study. Possible implications for the determination of the mean crushing force from analytical and numerical models are identified and discussed.     

基于UG的一种平面凸轮磨削方法在机床上的应用

介绍了一种基于UG的新型平面凸轮磨削方法便是在这个基础上提出的,并成功开发了针对平面凸轮磨削的专用机床.该机床较传统的凸轮加工有更高的精度与效率,较低的加工成本,有很大的经济效益.     

基于Matlab和Excel设计凸轮轮廓曲线

提出一种基于解析法设计凸轮轮廓线的原理,以Matlab为平台,Excel为中间站,通过人机交互式作图,实现了在AutoCAD中的凸轮轮廓的绘制.     

凸轮联动ATC的设计研究

通过对凸轮联动的动作分析,对凸轮曲线的设计及驱动计算做了说明,探讨了凸轮联动ATC设计中的有关技术问题。     

平底从动件盘形凸轮机构的研究

根据已知凸轮机构运动简图，提出了凸轮轮廓参数确定平底从动件运动规律的分析算法，建立了相应的代数算式；并在此基础上，导出了根据预定的从动件运动规律确定凸轮轮廓参数的代数算式；并验证了算法的正确性。     

凸轮传动机构的振动分析

凸轮机构是常用的传动控制机构，这里建立了凸轮传动机构的振动模型，分析了从动件的运动规律。分析表明由于从动件具有弹性元件的特性，因而运行过程中会产生振动，从而导致其实际运动位置与给定位置发生偏差，在凸轮机构的设计和应用中必须重视这一问题。