高效铣环在胜科1井事故处理中的应用

胜科1井是中国石化的一口重点科学探井,在钻至井深5001m时因井眼缩径发生了卡钻事故。由于井底存在直翼扩大器、PDC钻头等含有硬质合金的落鱼,普通铣鞋无法完成套铣打捞作业,为此,专门设计了一种高效铣环。该铣环的切削元件选用了一种硬度达93.2 HRA的钛合金,经铣槽镶焊在本体上;本体选用了40CrNiMo厚壁管材,并进行了调质处理;连接螺纹选用了双级梯形同步螺纹。在胜科1井的应用表明：切削元件的强度满足了切削扩大器切削翼和PDC钻头胎体的需要,其齿形、布齿方向和出刃高度设计合理,提高了切削速度;本体性能高,切削元件焊接性能较好;双级梯形同步螺纹有效增加了连接部位的强度,具有较高的上扣扭矩,承受冲击载荷能力强。高效铣环在该井的成功应用,为今后同类型井的事故处理提供了借鉴。     

Powder Deposition in Three Parallel-Oriented Dies of Different Shapes

Uniformity of bulk density distribution during the die filling process is required to minimize quality problems, such as distortion and cracking, for powder compacts. Understanding the die filling process is necessary in ensuring a uniform powder deposition. The second-generation pressure deposition tester (PDT-II) was used to investigate the deposition process and final pressure distribution of powder filling in toroidal, cylindrical, and E-shaped dies. All tests were conducted using a spray-dried free-flowing granular powder. The results indicated that for toroidal dies: (1) the area around 0° orientation (the leeward end) had the highest pressure values (1186.7 to 2498.0 Pa), with the average pressure values of the remaining area 353.7-648.0 Pa; (2) the pressure distribution was symmetrical about the centerline parallel to the feed shoe movement direction; (3) the highest feed shoe speed (500 mm/s) led to the most nonuniform pressure distribution among the three speeds; (4) higher feed shoe speed did not always result in higher final pressure values; and (5) the right die tended to have higher final pressure values (215.0 to 2498.0 Pa) than the center die (95.4 to 2052.5 Pa). For E-shaped dies: (1) the final pressure values of the middle leg (308.9 to 760.7 Pa) were higher than those of the left and the right legs (148.9 to 530.3 Pa); (2) the area along the backside had the highest final pressure value (1054.6 to 1303.8 Pa); (3) the pressure distribution was symmetrical about the centerline parallel to the feed shoe movement direction; and (4) neither the center die nor the right die always had higher pressure values than the other one at all locations. Comparison between cylindrical and toroidal dies indicated that: (1) neither of the two die shapes (cylinder and toroid) led to consistently higher or lower final pressure values at all locations and (2) for all three feed shoe speeds, the toroidal die had higher average final pressure values in the 0° orientation.     

基于点云数据的鞋楦数控编程及其仿真

在刻楦机的数控编程中,文章针对测量所得的鞋楦点云数据,利用一种常见的方法来处理点云数据并进行了针对鞋楦离散模型的刀轨计算,并介绍了如何利用CGTech公司的Vericut软件来进行刀轨仿真.     

不变黄HDI-PU/P(MMA-HEMA)互穿网络胶粘剂形态与性能的研究翁祥

制备了HDI(1,6-己二异氰酸酯)型聚酯聚氨酯/聚(甲基丙烯酸甲酯-甲基丙烯酸-β羟乙酯)(HDI-PU/P(MMA-HEMA))互穿网络胶粘剂,研究了接枝剂甲基丙烯酸-β羟乙酯(HEMA)用量对其形态、性能与分子结构的影响。结果表明,接枝剂HEMA可使分散相接枝到连续相中形成复合网络,从而改善其界面的相容性,提高其胶液粘度和初粘力,并可广泛作为制鞋工业用胶。     

Duration of slip-resistant shoe usage and the rate of slipping in limited-service restaurants: results from a prospective and crossover study

Several studies have indicated that slip-resistant shoes may have a positive effect on reducing the risk of slips and falls, a leading cause of injury at work. Few studies, however, have examined how duration of shoe usage affects their slip-resistance properties. This study examined the association between the duration of slip-resistant shoes usage and the self-reported rate of slipping in limited-service restaurant workers. A total of 475 workers from 36 limited-service restaurants in the USA were recruited to participate in a 12-week prospective study of workplace slipping. Of the 475 participants, 83 reported changing to a new pair of shoes at least once during the 12-week follow-up. The results show that slip-resistant shoes worn for less than six months were moderately more effective than those worn for more than six months. Changing to a new pair of shoes among those wearing slip-resistant shoes at baseline was associated with a 55% reduction in the rate of slipping (RR = 0.45, 95% CI = 0.23–0.89). Further research is needed to develop criteria for the replacement of slip-resistant shoes.

Practitioner Summary: The duration of usage impacts the slip-resistance properties of slip-resistant shoes. Slip-resistant shoes worn for less than six months were moderately more effective in reducing slips than slip-resistant shoes worn for more than six months. Shoe use policies should not only encourage or require their use but also include guidance on replacing slip-resistant shoes at regular intervals.     

新型聚醚聚氨酯微孔弹性体的研制

采用新型低不饱和度聚醚多元醇、合适的丰预聚体，合成了可用于鞋底材料的聚醚型聚氨酯微孔弹性体材料。与聚酯型和传统聚醚型鞋料相比，该新型聚醚鞋料在低温性能和耐挠曲性能方面显示出较强的优势。     

基于轴变形的脚楦匹配方法*

提出并实现了通过脚楦匹配方法来仿真人脚穿上鞋子的状态,能够直观、便利地检查和分析鞋类产品的舒适度。该方法包括三个步骤：首先,保持鞋楦的位置不动,调整脚型的位置,使其与鞋楦严格对齐;其次,基于轴线变形算法,对脚型进行略微变形,使其与鞋楦姿势匹配;最后,根据匹配结果生成脚楦多个截面的分析图,指导对鞋楦舒适度的分析和楦体修改。实验结果表明,该方法能够有效地检查鞋楦的舒适度,可应用到个性化定制业务。     

基于UG的鞋楦数控编程技术

由于鞋楦的自由曲面复杂性和数控刻楦机加工鞋楦的工艺特殊性，难以利用一般的数控编程方法对鞋楦CAD模型进行数控编程，本文提出一种应用UG软件生成鞋楦NC程序的方法，并进行了验证，简单而有效的解决了鞋楦螺旋环切式加工中的数控编程问题；该方法也同样适用于类似加工方式下其它自由曲面零件的数控编程。     

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 文章详细分析了2050粗轧机R2十字铰链滑块式万向接轴轧辊侧开式铰链铜衬瓦磨损寿命低并出现咬死现象的原因。金相分析表明，摩擦面产生严重的剪切塑性变形，变形层深达1.54 mm，但只出现在整个摩擦面的较小一部分，是摩擦剪应力大于材料的许用剪应力而造成。改善摩擦副的润滑条件、降低摩擦系数、提高材料的屈服强度与抗粘着能力，是正长铜衬瓦使用时间的基本途径。     

基于AT89C52的矿用绞车闸瓦综合保护系统

针对目前绞车闸瓦的保护设备存在可靠性和实时性较差的问题,设计了一种基于AT89C52的矿用绞车闸瓦综合保护系统,详细介绍了系统硬件和软件的设计。该系统利用传感器采集闸瓦间隙、闸瓦贴闸压力、闸瓦油压和温度等信号,并将采集的信号送至单片机处理,与设置值进行比较,如正常就显示检测到的数据,否则报警,实现了对闸瓦的实时监测和综合保护。