硬度塞法测量柴油机缸盖温度的实验研究

简要介绍了硬度塞法测量温度的原理和方法.并用硬度塞法分两种工况对柴油机缸盖的温度进行了实验测量,以了解柴油机缸盖的热负荷状况和考察其对热负荷的耐受能力.最后对测量结果进行了分析和研究,得出了一些有益的结论.     

45 t-30m岸边宽厚板装船机

介绍了45 t-30 m岸边宽厚板装船机的结构特点、主要技术性能参数,以及电控永磁吊具和回转吊架在宽厚板装船机上的应用.     

高速列车头部气动性能的模拟计算与试验

为了研究高速列车的头形对列车整车的气动性能有着重要的影响,对一节半车编组列车分别进行了空气动力学仿真分析和风洞试验．采用有限体积法对列车头部周围流场进行区域离散,进行气动性能仿真分析,得到高速列车头车的气动特性参数．在满足几何相似的基础上,对一节半编组的列车模型进行风洞试验,获取头部的气动参数,并从模拟仿真分析结果与风洞试验结果对比分析中验证,两种方法能够相互补充,相互印证,为高速列车头形的研究总结出有效的研究途径．     

发动机缸盖的机加工艺及加工难点

发动机缸盖作为复杂零件,表述繁杂,文章从使用功能角度介绍了缸盖各部位重要程度,分析了缸盖与相关零部件装配关系,指出缸盖机加工艺路线的核心原则,同时阐述了其关键部位的加工方法及注意事项。实践表明,该原则及方法有助于把握缸盖加工关键,灵活编排工艺。     

多锤头碎石化技术在路面改造工程中的应用

对旧水泥混凝土板采用碎石化技术进行处理,是目前世界上一种较先进的方法。通过对碎石化技术的简单介绍,肯定其优点,提出最优的机械搭配方案,最终利用试验可确定最佳的破碎参数、施工工艺及施工要求。     

和谐电力机车CCB-Ⅱ制动机EBV故障分析及建议

对和谐电力机车CCB-Ⅱ制动机各类EBV故障进行分类分析,阐述了HXD1B型机车出现自动减压故障时机车控制系统记录的EBV手柄位置信息的异常点,总结了处理自动减压故障的思路,并对CCB-Ⅱ制动机提出了具体改进意见。     

发动机缸盖罩漏油原因分析与对策

发动机缸盖罩漏油是影响汽车发动机性能和整车性能的重要问题之一,文章针对发动机缸盖罩漏油的原因进行分析,发现发动机缸盖罩和缸盖的连接橡胶圈老化导致密封性下降是漏油的主要原因,通过将原紧固方式更改为刚性联接方式彻底解决了发动机缸盖罩漏油的问题。     

A method to calculate and counterbalance the inertia force of slider-crank mechanisms in high-speed presses

A new method to calculate and counterbalance the inertia force of slider-crank mechanisms in high-speed mechanical presses was put forward. By analyzing the kinematic characteristics of a center-located slider-crank mechanism whose crank rotates at a constant angular velocity, the kinematic parameters of the slide, connecting rod and crank were formulated approximately. On the basis of the results above, three inertia forces and the input moment in the mechanism during its idle running were investigated and formulated by dynamic analysis. A verification experiment was performed on a slider-crank mechanism at a high-speed press machine. The forces derived from the established formulas were compared respectively with those obtained by the ADAMS software and the classical method of connecting rod mass substitution. It was experimentally found that the proposed formulas have an improved performance over related earlier techniques. By use of these results, a 1000 kN 1250 rpm four-point high-speed press machine was designed and manufactured. The slide of this press is driven by four sets of slider-crank mechanisms with symmetrical layout and opposite rotation directions to counterbalance the horizontal inertia forces. Four eccentric counterbalance blocks were designed to counterbalance the vertical force after their mass and equivalent eccentric radius were formulated. The high-speed press machine designed by the proposed counterbalance method has worked with satisfactory performance and good dynamic balance for more than four years in practical production.     

TREATMENT OF ISCHEMIC NECROSIS OF FEMORAL HEAD BY THE FREE TRANSFERRING FIBULAR BONE GRAFT WITH VASCULAR PEDICLE IN ADULTS：A

ＭａｏＬｕｚｈｅｎ（毛履真）；ＷａｎｇＫｕｎｚｈｅｎｇ（王坤正）；ＨｅＸｉｊｉｎｇ（贺西京）；ＬｉｕＡｎｑｉｎｇ（刘安庆）；ＬａｎＢｉｎｓｋａｎｇ（兰斌尚）ＴＲＥＡＴＭＥＮＴＯＦＩＳＣＨＥＭＩＣＮＥＣＲＯＳＩＳＯＦＦＥＭＯＲＡＬＨＥＡＤＢＹＴＨＥＦＲ...     

贝雷片龙门吊主梁失稳分析及处理方法

根据材料学知识及数学方法分析了贝雷片龙门吊发生的主梁扭曲变形的原因,根据原因提出了加大主梁水平桁架的抗弯截面模量等处理办法,实践证明这种方法是可行的.