毕业设计-18吨桥式起重机设计-机械部分

资源目录里展示的全都有，所见即所得。下载后全都有,请放心下载。原稿可自行编辑修改=【QQ：401339828 或11970985 有疑问可加】 附录1 Crane Work Needs More Technique Crane work needs more technology. Construction of tower cranes are the main vertical transportation equipment and also a measure of construction companies and equipment strength of the important logo, in today's increasingly competitive construction market, to meet the construction needs of many construction companies have bought the tower crane. With the tower crane at the construction site of the widely used by the tower crane accident also caused more and more to people's lives and property brought about great losses. According to national statistics, the departments concerned, the tower crane accident rate reached 2.77 percent. Its security problem is still the urgency of the construction Loose training, testing and oversight requirements for the people who work around construction cranes have fostered a false sense of security in our industry. The recent deadly tower-crane collapse at a congested New York City building site should be a wake-up call for us to question and step up our current safety practices. Training and testing is king when it comes to safety. But the construction industry is putting unqualified personnel in the seats of construction cranes, even with today's testing. In many places, no experience is necessary after passing a standardized test. One week of study will give some people enough knowledge to pass a certification examination, and then they can jump into the cab of a crane. Imagine that a commercial airline pilot had the same training as a certified crane operator. How would you feel the next time you decided to fly? In California, it takes more hours of training to wield a pair of scissors in a hair salon than to operate potentially dangerous lifting machinery. How does this make sense? Riggers and signal persons also need standard training and testing to ensure safety under the hook. Employers usually allow any craft to signal a crane on a jobsite, despite best practices that require only qualified people do so. How is it then that uncertified and untrained people are allowed to signal and rig under the hook of a licensed or certified operator? Tower cranes are particularly risky as urban sites become more congested, and the risk of a catastrophic event is very high during climbing operations. Yet most tower-crane climbing crews are trained in a non-traditional manner, via secondhand knowledge that has been passed down over time. The problem with this type of hand-me-down knowledge is that it changes over the years, leaving out small-but-important details along the way. This "osmosis" of knowledge leads crews to develop their own tricks for climbing cranes, often forsaking basic safety in an attempt to save time and energy. In many cases, there are no safety devices or alarms to warn of a serious problem. Climbing crews are subjected to pressures that affect safety-critical decision-making. It is not uncommon for climbs to continue with damaged or leaking hydraulic systems, out-of-adjustment or jammed guide rollers, often working in the dark and for extended hours. This "MacGyver" method of climbing, where every jump becomes a new adventure, should not be the norm. Climbing-frame designs vary among manufacturers, but the operational steps are similar in principle. The climbing process is relatively straightforward, with a mixture of physical work and technical procedure. It is not complex; it is more about knowing the proper sequence of what needs to be done and then following the steps, one by one, making sure each step has been successfully completed before moving onto the next. It is essential that everyone know exactly what is going on and what the dangers are at every stage. That's why the industry needs standardized training, testing and oversight for this work, including a practical assessment of competence. Technicians should have model-specific training directly from the manufacturer, along with a level of practical experience. Inspectors, too, should be required to have specific technical training. They should be independent from all aspects of installation and maintenance to allow for objective decisions. Key personnel on erection crews should have standard training and testing. When these needs are satisfied, crane operations should be carried out in strict accordance with the manufacturers' instructions, engineering principals and governmental laws. But industry stakeholders and lawmakers need to step up their lax standards to protect the public. New York City residents, who have seen their homes turned into dust and debris, would be shocked at the way the industry deals with these issues. The birth worldwide industry early post-war years, the crane industry came to an aImost complete standstill. By the end of the decade, however, crane construction had diversified and spread around the world and the industry seemed infused with newfound energy that left it flourishing as never before. Lightweight cranes that arrived on site ready for use came to dominate construction sites as people realised the advantages of not having to dismantle them between jobs. These new designs did away with the need to have other lifting equipment assisting during rigging - a big contrast to the cumbersome rigging of previous designs. But, before all this could happen came the horrors of the Second World War. By 1940 afl of Europe was completely caught up in the conflict. By the time the war ended, Europe and other parts of the world had been subjected to extraordinary political, economic and social changes that would affect the entire  fabric of society, including the construction and crane industries, for many decades to come. In the US, steam locomotives were starting to be replaced by diesel - by 1953 more than 50 per cent of all locomotives would be diesel. During the war the mass production of excavators, scrapers and cranes continued. 1940, for example, saw Thew launch the new 'Lorain Motocrane' series. This consisted of three cranes which, for the first time in history, were mounted on chassis built by the crane manufacturer itselfi The smallest crane, the MC-2, could lift 7.6 tonnes, the MC-2 9.9 tonnes and the MC-3 13.5 tonnes. These cranes were delivered to the army by the thousand, and were also mounted on portals for use as harbour cranes (the MC-4 model). The war had, of course, taken its toll on the number of able-bodied men available to work in the crane industry and there was a serious shortage of good crane drivers. At Thew, newcomers were taught crane operations over a two-day course presented by A C Burch, an experienced mechanic and graduate of the Naval Academy, and L K Jenkins. These two gentlemen were probably the originators of 'operator training' as we know it today. As they had actually designed the Motocrane, both knew it inside out and were pleased to pass on this knowledge. In response to the long-standing problems,in which the swinging angle of the hoisted load and the velocity of swinging angle is difficult to measure in engineering practice,a state observer is designed by the use of information about the crane trolley's position,and as a result,the trolley load-hoisting system combines with the state observer so conceived to form an online soft measurement system.By introducing the difference between the observer's output and that of the trolley load-hoisting system,and transmitting it to the output end of the observer upon gain vector adjusting by the observer,the pole points of the observer are configured on the same point at the negative real axle,thereby realizing a stable,fast soft measurement for the system variables.Simulation experiments show that:the online soft measurement system possesses a fairly high level of robustness;as the pole points grow,however,the soft measurement system grows in the scope of adaptability to changes in the hoisted ...更多load and in the length of the hoisting wire rope.But as the pole points overly grow,a sudden increase in measurement errors may occur either way;when the pole points are set,the result of a soft measurement is more sensitive to the length change of the hoisting rope than to the change of the hoisted load. 起重机的工作需要更多的科学技术 塔式起重机是建筑施工垂直运输的主要设备，也是衡量一个建筑施工企业装备实力的重要标识，在当今竞争日益激烈的建筑市场，为满足施工需要，很多施工企业都购置了塔式起重机。随着塔式起重机在施工现场的广泛使用，由塔式起重机引发的伤亡事故也越来越多，给人民的生命财产带来重大损失。据国内有关部门统计资料表明，塔式起重机的事故率已达2.77%。其安全问题仍然是建筑施工中的忧患……起重机的工作需要更多的科学技术， 松散的培训，测试和监督的要求, 周围的建筑起重机给这些工作的人树立了一种虚假的安全感，在我们的行业。最近塔式起重机倒塌在一个繁忙的纽约市建筑地盘应敲响警钟，提醒我们问题的存在，并加强我们目前安全的做法。 当谈到安全问题时，训练和测试是关键。不过，建造业是把不合格人员放在建筑起重机的驾驶位上，甚至没有通过今天的测试。在许多地方，没有任何经验必须合格的通过标准化的测试。一周的学习将给予一些人足够的知识足以通过认证考试，然后他们可以跳转到的起重机的驾驶室。 想象一下一个商业航空公司飞行员和一个认证的起重机操作员有相同的训练。你会如何感觉，下一次你决定要坐飞机？在加利福尼亚州，掌握一对剪刀在头发沙龙比操作有潜在危险的起重机械需要更多的时间训练。如何，这是否合理？ 装配工人和发信号的人也需要标准的培训和测试，以确保安全下钩。雇主通常允许任何工人发信号指挥起重机上工地 ，尽管最佳做法是需要合格的人这样做。怎么能允许那么无证和未受过训练的人来代替有工作证或经核证的操作者呢？ 塔式起重机是特别危险的，尤其是在市区用地变得更加拥挤时。攀登行动更是一个风险的行动，其灾难性非常高。然而，大多数塔式起重机攀登员的训练，在一个非传统的方式，通过二手知识已流传一段时间。问题与这种类型的现成的知识是，多年来，留下来的非常少，但最重要的细节却丢失了。这种“渗透”的知识，导致操作者只能发展自己的技巧攀登起重机，往往放弃基本的安全，企图以节省时间和能源. 在许多情况下没有安全装置或警报来提醒严重的问题的存在。攀登人员容易遭受到影响安全性至关重要的决策所带来的压力。攀登时，使用损坏或泄漏的液压系统，没有任何的调整，这并不鲜见。在黑暗中工作和延长工作时间是时有发生的。这种攀登方法，其中的每一次攀登都会成为新的冒险，不应该作为规范被采纳。 攀爬架的设计，在制造商之间存在不同，但设计的步骤在原则上是相似的。攀登过程中是相对比较明了的，配合着的体力劳动和技术程序。这是并不复杂，它是更多地了解知道正确的序列需要做什么，然后按照下列步骤，一个又一个，确保每一步在做下一步前成功完成。这是十分重要，每个人都清楚的知道事情进展的怎么样，在每一个阶段存在什么样的危险。 这就是为什么业界需要规范的培训，测试和监督，其中包括一个实际的评估能力。技术人员应该随着实际经验的提升，直接从制造商哪里获得标准训练。视察员同样也也须有具体的技术培训。他们应独立于安装和维修的各方面，这由客观决定。架设的关键人员应该有标准的训练和测试. 当这些需要得到满足，起重机作业应进行严格按照有关制造商的指示，工程原则和政府的法律。但业内人士和国会议员，要加强他们的宽松标准，以保障公众利益。看到自己的家园变成了尘埃和碎片的纽约市居民，会对处理这些问题的方式感到震惊。 战后的前几年，世界性的工业诞生了，起重机行业几乎完全停止。然而到这个年代末，起重机的建造变得多元化并传播到世界各地，它的前所未有的蓬勃发展似乎整个工业注入了新能源。轻型起重机投入到工作地点并准备作为主要机械，因为人们意识到了在工作间不用拆除他们的的优点。这些新的设计也不再需要其他起重设备协助操纵——相比以前在安装前要进行繁琐的设计。但是，在这一切之前发生了恐怖的第二次世界大战。到1940年，欧洲完全陷入了战争中。到战争结束后的几十年来，欧洲和世界其他地区发生了巨大的政治，经济和社会变化，将影响整个社会结构，包括建造业和起重机行业。在美国，蒸汽机已开始改为柴油机——到1953年超过百分之五十的机车将使用柴油机。战争期间，挖掘机，铲运机和起重机的大规模生产在继续。例如1940年，看到Thew推出新的'Lorain Motocrane'系列。这其中包括三种起重机，是历史上首次自身安装了底盘的起重机。最小的MC - 2 ，起重量达7.6吨， MC – 2起重量为9.9吨，MC – 3起重量为13.5吨。这些起重机许多被用于军队，有的还安装在港口用作港湾式起重机（在MC - 4型） 。当然，这场战争已经削弱了能在起重机行业工作的健壮的男人的数量，并且优秀的起重机司机严重短缺。在Thew ，一位毕业于美国海军学院的经验丰富的技工A C Burch和L K Jenkins进行了为期两天的起重机业务课程的教授。这两位绅士好比是我们今天所知的“经营者培训”的创始人。他们实际上已设计了动力起重机，都深深地了解起重机，并很高兴传授这方面的知识。 针对工程实际中起重机吊重摆角和摆角角速度不易测量的问题,利用小车位置信息设计了状态观测器,小车吊重系统和观测器构成在线软测量系统。通过引入观测器输出与小车吊重系统输出之间的差值并经过观测器的增益向量调节送至观测器的输入端,将观测器的极点配置在负实轴的同一点上,实现对系统变量稳定、快速软测量。仿真试验表明,在线软测量系统具有较强的鲁棒性;随极点增大,软测量系统对吊重和绳长变化具有更宽的适应范围,但极点过大时,会出现测量误差上冲或下冲现象;当极点确定时,软测量效果对绳长变化比吊重变化敏感。