2404 冲压废料自动输送装置设计
2404 冲压废料自动输送装置设计,冲压,废料,废物,自动,输送,装置,设计
附件 3:邵阳学院毕业设计(论文)任务书年级专业 2004 级机制专科专业 学生姓名 尹婷 学 号 0430817055课题名称 冲 压 废 料 自 动 输 送 装 置 设 计设计(论文)起止时间 2007 年 3 月 20 日至 2007 年 6 月 9 日课题类型 工程设计 课题性质 真实一、课题设计(研究)的目的和主要内容研究目的:综合机械制造专业所学课程的理论和实践知识,进行一次实际解决问题的设计,培养学生独立解决设计和制造上理论与实际问题的能力, 提高学生资料查阅和灵活使用软件语言的能力。完成工厂冲压废料自动输送装置的设计。主要内容:设计出一台适应不同模具尺寸的冲压废料自动输送装置,使用一台马达同时驱动多条输送带,解决了一台马达驱动一条输送带所带来的横向空间不够的问题。使废料收集更方便、安全。提高生产效率。二、基本要求1、必须独立完成毕业设计工作。2、完成装备图、主要部件图、重要的零件图、皮带运输机的电气原理图。3、按学院毕业设计的书写格式要求,撰写设计说明书,毕业设计说明书不少于 30000 字。4、应完成 3000-5000 个文字的与毕业设计有关的外文资料翻译, 译文要求准确,文字流畅。注:1、此表由指导教师填写,经各系、教研室主任审批,指导教师、学生签字后生效;2、此表 1 式 3 份,学生、指导教师、教研室各 1 份。三、课题研究已具备的条件(包括实验室、主要仪器设备、参考资料)1、实习工厂冲压设备。2、邵阳学院图书馆相关资料:如主要参考资料:冲压设备 , 机械设计手册 , 机械设计, 机床电气控制原理, 期刊杂志模具工业 、 冲压技术 、 冲压工艺 、中国冲压件网、冲压废料处理网。3、课题前期的调查、研究工作四、设计(论文)进度安排2 月 20 日3 月 20 日:调研、资料准备、确定方案、绘制草图;3 月 21 日4 月 21 日:完成装配图、部件图、零件图;4 月 22 日5 月 22 日:编写设计说明书;5 月 23 日6 月 10 日:校对、总结、准备答辩。五、教研室审批意见教研室主任(签字) 年 月 日六、系审批意见系主任(签字) 单位(公章) 年 月 日指导教师(签字): 学生(签字):邵 阳 学 院毕业设计(论文)开题报告书课 题 名 称 冲压废料自动输送装置 学 生 姓 名 尹 婷 学 号 0430817055 系 、 专 业 机 械 与 能 源 工 程 系 机 械 制 造 工 艺 与 设 备 指 导 教 师 陈 志 刚 2007 年 3 月 20 日一、课题的来源、目的意义(包括应用前景) 、国内外现状及水平课题来源:目前还有很多工厂的冲压废料清除方式都是最原始的人工清扫,机箱装载。手工生产线需停机清扫,自动生产线虽不停机,但清扫时极不安全。同时手工清扫废料及目前废料收集方式使整个生产现场显得零乱。废料满地散落,场地不清洁,人工清除废料势必停机作业,影响生产效率。目的:通过综合运用所学的知识,在老师的指导下解决实际工程问题,培养学生理论联系实际的能力,良好的设计思想和工作作风。意义:本次设计是要求解决实际的工程问题,不仅要求掌握具有相当的专业知识,还可以锻炼独立解决问题的能力,提高查阅设计手册的能力,熟悉相关的国家标准的国际标准,更加熟练操作绘图软件绘制工程图。最重要的是能让我们学到的理论知识运用到实践中,提高实践能力。使我们的设计更具实用性,能为社会发展贡献自己的一份微薄之力。本次设计还能让我们更多的接触社会,了解社会的发展态势和国内外的研究现状,为自己以后的发展奠定基础。应用前景:本课题就针对模具垫脚高度、间距及位置不一,夹模器的干涉,如何从模下自动清除废料等问题,设计一种适应性强,效率高,安全可靠的废料自动输送装置。应用相当的广泛。国内外现状及水平:在冲压作业中,冲压机械设备、模具、作业方式对安全影响很大。实现冲压机械化和废料收集自动化,能大幅度提高冲压设备的利用率和劳动生产率并保证人身安全。但是,冲压作业的动作频率高,又多数是薄板加工,所以保证冲压机械化和废料收集自动化的可靠性在技术上实现的难度较大。冲压废料的收集常常需要停机工作,既影响生产,又极不安全。目前,国内、外研究的输送装置往往只针对一种冲压产品,当遇到模具垫脚高度、间距及位置不一,夹模器的干涉等问题时, ,从模下自动清除废料非常困难,本课题着重解决以上问题,设计制造完成以后,将在国内得到广泛地应用。二、课题研究的主要内容、研究方法或工程技术方案和准备采取的措施课题研究的主要内容:冲压废料自动输送装置的设计,包括:设计出一台适应不同模具尺寸的冲压废料自动输送装置,使用一台马达同时驱动多条输送带,解决了一台马达驱动一条输送带所带来的横向空间不够的问题。使废料收集更方便、安全。提高生产效率。工程技术方案和准备采取的措施:1、使用一台马达同时驱动多条输送带,解决了一台马达驱动一条输送带所带来的横向空间不够的问题;2、输送带横向位置可任意调整,以适应不同的垫脚位置。3、一种输送带宽度可适应一定范围的垫脚间距,输送带可任意组合,以适应不同的模具尺寸。4、换模时可方便地移动输送带,且各皮带整体及单位皮带伸入模具下的深度可调,适应不同的模具尺寸。5、换线时,可方便地更换输送带。6、超薄皮带可越过夹模器或压板地阻挡,更好地利用空间。7、本次设计全面满足用户要求的各项标准、规范要求,同时参考国际标准,对产品进行全面的优化设计。三、现有基础和具备的条件通过大学四年的学习,本人已经掌握了基本的专业知识,对本课题的相关学科有一定的了解,具有了相关的理论基础。学校还组织进行了各种课程设计,积累了一定的经验,对本次设计将会有很大的帮助。学校提供了大量的相关资料、技术支持以及实验设备和实验场地。学院图书馆收藏了许多有关专业方面的知识书籍和周刊,并且提供了网络化的机房,可以在中国期刊网、维普网、万方数据库、超星数字图书馆等网站查阅有关资料。对目前工厂的各种冲压设备的废料输送的调查及论证,一些非自动的冲压废料输送装置的运用,运输机械的调研和在实际中的应用。现具有的一些参考资料如:(1) 、 机械设计手册(2) 、 链传动(3) 、 连续运输机(4) 、 机械设计(5) 、 冲压设备(6) 、 输送机设计手册(7) 、 电工技术(8) 、 机床电气控制原理除了以上的资料,还有冲压机自动输送装置的一些图样及其相关的资料、AUTOCAD 绘图软件、OFFICE 办公软件等。四、总的工作任务,进度安排以及预期结果总的工作任务:总装配图的绘制和主要零件图的绘制;说明书的编写(万字) ;翻译相关英文资料 1 篇。进度安排:2 月 20 日3 月 20 日:调研、资料准备、确定方案、绘制草图3 月 21 日4 月 21 日:完成装备图、部件图、零件图4 月 22 日5 月 22 日:编写设计说明书5 月 23 日6 月 10 日:校对、总结、准备答辩预期结果:完成 1 篇相关英文资料的翻译。完成对输送机的结构和功能分析,确定总体方案设计,并绘制出装配图。完成电动机、输送装置设计计算和零部件图的绘制,撰写详细的设计说明书。我希望能提前完成任务,并且把错误降低到最低点,使本设计具有相当的实用性。五、指导教师审查意见指导教师(签名) 年 月 日 六、教研室审查意见教研室主任(签名) 年 月 日 七、院(系)审查意见院(系)主任(签名) 年 月 日 备 注1A Comparison of Soft Start Mechanisms for Mining Belt ConveyorsMichael L. Nave, P.E.CONSOL Inc.1800 Washington Road Pittsburgh, PA 15241 Belt Conveyors are an important method for transportation of bulk materials in the mining industry. The control of the application of the starting torque from the belt drive system to the belt fabric affects the performance, life cost, and reliability of the conveyor. This paper examines applications of each starting method within the coal mining industry.INTRODUCTIONThe force required to move a belt conveyor must be transmitted by the drive pulley via friction between the drive pulley and the belt fabric. In order to transmit power there must be a difference in the belt tension as it approaches and leaves the drive pulley. These conditions are true for steady state running, starting, and stopping. Traditionally, belt designs are based on static calculations of running forces. Since starting and stopping are not examined in detail, safety factors are applied to static loadings (Harrison, 1987). This paper will primarily address the starting or acceleration duty of the conveyor. The belt designer must control starting acceleration to prevent excessive tension in the belt fabric and forces in the belt drive system (Suttees, 1986). High acceleration forces can adversely affect the belt fabric, belt splices, drive pulleys, idler pulleys, shafts, bearings, speed reducers, and couplings. Uncontrolled acceleration forces can cause belt conveyor system performance problems with vertical curves, excessive belt take-up movement, loss of drive pulley friction, spillage of materials, and festooning of the belt fabric. The belt designer is confronted with two problems, The belt drive system must produce a minimum torque powerful enough to start the conveyor, and controlled such that the acceleration forces are within safe limits. Smooth starting of the conveyor can be accomplished by the use of drive torque control equipment, either mechanical or electrical, or a 2combination of the two (CEM, 1979).SOFT START MECHANISM EVALUATION CRITERIONWhat is the best belt conveyor drive system? The answer depends on many variables. The best system is one that provides acceptable control for starting, running, and stopping at a reasonable cost and with high reliability (Lewdly and Sugarcane, 1978). Belt Drive System For the purposes of this paper we will assume that belt conveyors are almost always driven by electrical prime movers (Goodyear Tire and Rubber, 1982). The belt drive system shall consist of multiple components including the electrical prime mover, the electrical motor starter with control system, the motor coupling, the speed reducer, the low speed coupling, the belt drive pulley, and the pulley brake or hold back (Cur, 1986). It is important that the belt designer examine the applicability of each system component to the particular application. For the purpose of this paper, we will assume that all drive system components are located in the fresh air, non-permissible, areas of the mine, or in non-hazardous, National Electrical Code, Article 500 explosion-proof, areas of the surface of the mine.Belt Drive Component Attributes Size.Certain drive components are available and practical in different size ranges. For this discussion, we will assume that belt drive systems range from fractional horsepower to multiples of thousands of horsepower. Small drive systems are often below 50 horsepower. Medium systems range from 50 to 1000 horsepower. Large systems can be considered above 1000 horsepower. Division of sizes into these groups is entirely arbitrary. Care must be taken to resist the temptation to over motor or under motor a belt flight to enhance standardization. An over motored drive results in poor efficiency and the potential for high torques, while an under motored drive could result in destructive overspending on regeneration, or overheating with shortened motor life (Lords, et al., 1978).Torque Control. Belt designers try to limit the starting torque to no more than 150% of 3the running torque (CEMA, 1979; Goodyear, 1982). The limit on the applied starting torque is often the limit of rating of the belt carcass, belt splice, pulley lagging, or shaft deflections. On larger belts and belts with optimized sized components, torque limits of 110% through 125% are common (Elberton, 1986). In addition to a torque limit, the belt starter may be required to limit torque increments that would stretch belting and cause traveling waves. An ideal starting control system would apply a pretension torque to the belt at rest up to the point of breakaway, or movement of the entire belt, then a torque equal to the movement requirements of the belt with load plus a constant torque to accelerate the inertia of the system components from rest to final running speed. This would minimize system transient forces and belt stretch (Shultz, 1992). Different drive systems exhibit varying ability to control the application of torques to the belt at rest and at different speeds. Also, the conveyor itself exhibits two extremes of loading. An empty belt normally presents the smallest required torque for breakaway and acceleration, while a fully loaded belt presents the highest required torque. A mining drive system must be capable of scaling the applied torque from a 2/1 ratio for a horizontal simple belt arrangement, to a 10/1 ranges for an inclined or complex belt profile.Thermal Rating. During starting and running, each drive system may dissipate waste heat. The waste heat may be liberated in the electrical motor, the electrical controls, the couplings, the speed reducer, or the belt braking system. The thermal load of each start Is dependent on the amount of belt load and the duration of the start. The designer must fulfill the application requirements for repeated starts after running the conveyor at full load. Typical mining belt starting duties vary from 3 to 10 starts per hour equally spaced, or 2 to 4 starts in succession. Repeated starting may require the dreading or over sizing of system components. There is a direct relationship between thermal rating for repeated starts and costs. Variable Speed. Some belt drive systems are suitable for controlling the starting torque and speed, but only run at constant speed. 4Some belt applications would require a drive system capable of running for extended periods at less than full speed. This is useful when the drive load must be shared with other drives, the belt is used as a process feeder for rate control of the conveyed material, the belt speed is optimized for the haulage rate, the belt is used at slower speeds to transport men or materials, or the belt is run a slow inspection or inching speed for maintenance purposes (Hager, 1991). The variable speed belt drive will require a control system based on some algorithm to regulate operating speed. Regeneration or Overhauling Load. Some belt profiles present the potential for overhauling loads where the belt system supplies energy to the drive system. Not all drive systems have the ability to accept regenerated energy from the load. Some drives can accept energy from the load and return it to the power line for use by other loads. Other drives accept energy from the load and dissipate it into designated dynamic or mechanical braking elements. Some belt profiles switch from motoring to regeneration during operation. Can the drive system accept regenerated energy of a certain magnitude for the application? Does the drive system have to control or modulate the amount of retarding force during overhauling? Does the overhauling occur when running and starting? Maintenance and Supporting Systems. Each drive system will require periodic preventative maintenance. Replaceable items would include motor brushes, bearings, brake pads, dissipation resistors, oils, and cooling water. If the drive system is conservatively engineered and operated, the lower stress on consumables will result in lower maintenance costs. Some drives require supporting systems such as circulating oil for lubrication, cooling air or water, environmental dust filtering, or computer instrumentation. The maintenance of the supporting systems can affect the reliability of the drive system.Cost. The drive designer will examine the cost of each drive system. The total cost is the sum of the first capital cost to acquire the drive, the cost to install and commission the drive, the cost to operate the drive, and the cost to maintain the drive. The cost for power to operate the drive may vary widely 5with different locations. The designer strives to meet all system performance requirements at lowest total cost. Often more than one drive system may satisfy all system performance criterions at competitive costs.Complexity. The preferred drive arrangement is the simplest, such as a single motor driving through a single head pulley. However, mechanical, economic, and functional requirements often necessitate the use of complex drives. The belt designer must balance the need for sophistication against the problems that accompany complex systems. Complex systems require additional design engineering for successful deployment. An often-overlooked cost in a complex system is the cost of training onsite personnel, or the cost of downtime as a result of insufficient training.SOFT START DRIVE CONTROL LOGICEach drive system will require a control system to regulate the starting mechanism. The most common type of control used on smaller to medium sized drives with simple profiles is termed Open Loop Acceleration Control. In open loop, the control system is previously configured to sequence the starting mechanism in a prescribed manner, usually based on time. In open loop control, drive-operating parameters such as current, torque, or speed do not influence sequence operation. This method presumes that the control designer has adequately modeled drive system performance on the conveyor. For larger or more complex belts, Closed Loop or Feedback control may he utilized. In closed loop control, during starting, the control system monitors via sensors drive operating parameters such as current level of the motor, speed of the belt, or force on the belt, and modifies the starting sequence to control, limit, or optimize one or wore parameters. Closed loop control systems modify the starting applied force between an empty and fully loaded conveyor. The constants in the mathematical model related to the measured variable versus the system drive response are termed the tuning constants. These constants must be properly adjusted for successful application to each conveyor. The most common schemes for closed loop 6control of conveyor starts are tachometer feedback for speed control and load cell force or drive force feedback for torque control. On some complex systems, It is desirable to have the closed loop control system adjust itself for various encountered conveyor conditions. This is termed Adaptive Control. These extremes can involve vast variations in loadings, temperature of the belting, location of the loading on the profile, or multiple drive options on the conveyor. There are three common adaptive methods. The first involves decisions made before the start, or Restart Conditioning. If the control system could know that the belt is empty, it would reduce initial force and lengthen the application of acceleration force to full speed. If the belt is loaded, the control system would apply pretension forces under stall for less time and supply sufficient torque to adequately accelerate the belt in a timely manner. Since the belt only became loaded during previous running by loading the drive, the average drive current can be sampled when running and retained in a first-in-first-out buffer memory that reflects the belt conveyance time. Then at shutdown the FIFO average may be use4 to precondition some open loop and closed loop set points for the next start. The second method involves decisions that are based on drive observations that occur during initial starting or Motion Proving. This usually involves a comparison In time of the drive current or force versus the belt speed. if the drive current or force required early in the sequence is low and motion is initiated, the belt must be unloaded. If the drive current or force required is high and motion is slow in starting, the conveyor must be loaded. This decision can be divided in zones and used to modify the middle and finish of the start sequence control. The third method involves a comparison of the belt speed versus time for this start against historical limits of belt acceleration, or Acceleration Envelope Monitoring. At start, the belt speed is measured versus time. This is compared with two limiting belt speed curves that are retained in control system memory. The first curve profiles the empty belt when accelerated, and the second one the fully loaded belt. Thus, if the current speed versus time is lower than the loaded profile, it may indicate that the belt is overloaded, 7impeded, or drive malfunction. If the current speed versus time is higher than the empty profile, it may indicate a broken belt, coupling, or drive malfunction. In either case, the current start is aborted and an alarm issued.CONCLUSIONThe best belt starting system is one that provides acceptable performance under all belt load Conditions at a reasonable cost with high reliability. No one starting system meets all needs. The belt designer must define the starting system attributes that are required for each belt. In general, the AC induction motor with full voltage starting is confined to small belts with simple profiles. The AC induction motor with reduced voltage SCR starting is the base case mining starter for underground belts from small to medium sizes. With recent improvements, the AC motor with fixed fill fluid couplings is the base case for medium to large conveyors with simple profiles. The Wound Rotor Induction Motor drive is the traditional choice for medium to large belts with repeated starting duty or complex profiles that require precise torque control. The DC motor drive, Variable Fill Hydrokinetic drive, and the Variable Mechanical Transmission drive compete for application on belts with extreme profiles or variable speed at running requirements. The choice is dependent on location environment, competitive price, operating energy losses, speed response, and user familiarity. AC Variable Frequency drive and Brush less DC applications are limited to small to medium sized belts that require precise speed control due to higher present costs and complexity. However, with continuing competitive and technical improvements, the use of synthesized waveform electronic drives will expand.
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