冷连续纵列式冷轧机的平直度模型和控制[中文4680字] 【中英文WORD】.zip

冷连续纵列式冷轧机的平直度模型和控制冷连续纵列式冷轧机的平直度模型和控制在 1994 年的下半年，Sidmar 一号纵列式冷轧机被改造为完全连续的五架轧机，并且配备了一条酸洗线。其轧机设备的组成包括：机架上的液压压下机构；第一架带有能轴向移动的中间辊的六辊轧机；所有机架的支撑辊；最后一个机架上的轴向移动的工作辊。这个新的冷轧技术和这条新的酸洗线允许酸洗过程、轧机出口尺寸和钢带平直度的闭式控制。它含有两条平直度测量系统：一是在轧机出口处，另一个是在机架间的缝隙。平直度是通过传统的第一架和最后一架之间的闭环反馈方法，用平直度在线模型在支撑辊和轴向移动设定的点来控制。在线模型用来描述 6、4 辊轧机轴向移动的平直度元素的线性、抛物线和四次方程。除了平直度反馈控制和在线模型设定以外，一种独特的反馈系统通过确认新来的钢带的外形的种类，用机架间的平直度测量来提高轧机出口平直度。新系统的所有客观性能都达到了提高所提供的产品范围的平直度质量的要求。平直度要求Sidmar 轧机轧制宽 6501880mm，厚 0.33.5 mm 和材料强度从低碳钢到 HSLA 和中碳钢范围的材料。从冷轧机出来的好的平直度的轧件能提高生产量和生产率，很容易满足客户最后的要求。典型地，平直度从原料改变到15 个单位需要经过入口到出口线，但根据残留错误的波长和型式的不同，轧件的不平度水平仍大大的改变。Sidmar 轧机的改造之后，在稳定运行的情况下，从原料到8 个单位是带卷平直度的标准性能，好于从原料到11 个单位，差于从原料到5个单位。在新轧制线上，轧制完成的带卷被剪短的时候，它和新来的热轧带卷之间有一两个焊缝。在这点上，它对平直度的干扰是尤为重要的，而且对单一反馈系统的反馈造成很大的困难。不同尺寸轧机的在线平直度要求物理模型的采用使得大多数机械结构的复杂的平直度模型能以一套基本的模型被建立。这个基本模型把物理原理转化为数学上的并作为模块代码的程序。模块代码被更改设定为模拟特殊机械排列到要求描述的形式的软件。举个例子，如相同的模型能被设定为一个图形的近似二次方程或线性描述、二次方程和四次方程，或者设定为更详细的遍布钢带的 50 个单位。Sidmar 轧机的在线装置模型需要线性的、二次的和四次的方程。外形模型包括下列模块：轧辊的挠度轧辊间接触应力轧辊面压痕抗拉强度钢带压力新设计本身会有许多缺陷和未能预料的问题发生，只有当这些缺陷和问题被解决之后，才能体现出新产品的优越性。因此，一个性能优越的产品诞生的同时，也伴随着较高的风险。应该强调的是，如果设计本身不要求采用全新的方法，就没有必要仅仅为了变革的目的而采用新方法。在设计的初始阶段，应该允许设计人员充分发挥创造性，不受各种约束。即使产生了许多不切实际的想法，也会在设计的早期，即绘制图纸之前被改正掉。只有这样，才不致于堵塞创新的思路。通常，要提出几套设计方案，然后加以比较。很有可能在最后选定的方案中，采用了某些未被接受的方案中的一些想法。心理学家经常谈论如何使人们适应他们所操作的机器。设计人员的基本职责是努力使机器来适应人们。这并不是一项容易的工作，因为实际上并不存在着一个对所有人来说都是最优的操作范围和操作过程。另一个重要问题，设计工程师必须能够同其他有关人员进行交流和磋商。在开始阶段，设计人员必须就初步设计同管理人员进行交流和磋商，并得到批准。这一般是通过口头讨论，草图和文字材料进行的。为了进行有效的交流，需要解决下列问题：（1）所设计的这个产品是否真正为人们所需要？（2）此产品与其他公司的现有同类产品相比有无竞争能力？（3）生产这种产品是否经济？（4）产品的维修是否方便？（5）产品有无销路？是否可以盈利？只有时间能对上述问题给出正确答案。但是，产品的设计、制造和销售只能在对上述问题的初步肯定答案的基础上进行。设计工程师还应该通过零件图和装配图，与制造部门一起对最终设计方案进行磋商。通常，在制造过程中会出现某个问题。可能会要求对某个零件尺寸或公差作一些更改，使零件的生产变得容易。但是，工程上的更改必须要经过设计人员批准，以保证不会损伤产品的功能。有时，在产品的装配时或者装箱外运前的试验中才发现设计中的某种缺陷。这些事例恰好说明了设计是一个动态过程。总是存在着更好的方法来完成设计工作，设计人员应该不断努力，寻找这些更好的方法。近些年来，工程材料的选择已经显得重要。此外，选择过程应该是一个对材料的连续不断的重新评价过程。新材料不断出现，而一些原有的材料的能够获得的数量可能会减少。环境污染、材料的回收利用、工人的健康及安全等方面经常会对材料选择附加新的限制条件。为了减轻重量或者节约能源，可能会要求使用不同的材料。来自国内和国际竞争、对产品维修保养方便性要求的提高和顾客的反馈等方面的压力，都会促使人们对材料进行重新评价。由于材料选用不当造成的产品责任诉讼，已经产生了深刻的影响。此外，材料与材料加工之间的相互依赖关系已经被人们认识得更清楚。因此，为了能在合理的成本和确保质量的前提下获得满意的结果，设计工程师的制造工程师都必须认真仔细地选择、确定和使用材料。制造任何产品的第一步工作都是设计。设计通常可以分为几个明确的阶段：（a）初步设计；（b）功能设计；（c）生产设计。在初步设计阶段，设计者着重考虑产品应该具有的功能。通常要设想和考虑几个方案，然后决定这种思想是否可行；如果可行，则应该对其中一个或几个方案作进一步的改进。在此阶段，关于材料选择唯一要考虑的问题是：是否有性能符合要求的材料可供选择；如果没有的话，是否有较大的把握在成本和时间都允许的限度内研制出一种新材料。在功能设计和工程设计阶段，要做出一个切实可行的设计。在这个阶段要绘制出相当完整的图纸，选择并确定各种零件的材料。通常要制造出样机或者实物模型，并对其进行试验，评价产品的功能、可靠性、外观和维修保养性等。虽然这种试验可能会表明，在产品进入到生产阶段之前，应该更换某些材料，但是，绝对不能将这一点作为不认真选择材料的借口。应该结合产品的功能，认真仔细地考虑产品的外观、成本和可靠性。一个很有成就的公司在制造所有的样机时，所选用的材料应该和其生产中使用的材料相同，并尽可能使用同样的制造技术。这样对公司是很有好处的。功能完备的样机如果不能根据预期的销售量经济地制造出来，或者是样机与正式生产的装置在质量和可靠性方面有很大不同，则这种样机就没有多大的价值。设计工程师最好能在这一阶段完全完成材料的分析、选择和确定工作，而不是将其留到生产设计阶段去做。因为，在生产设计阶段材料的更换是由其他人进行的，这些人对产品的所有功能的了解不如设计工程师。在生产设计阶段中，与材料有关的主要问题是应该把材料完全确定下来，使它们与现有的设备相适应，能够利用现有设备经济地进行加工，而且材料的数量能够比较容易保证供应。在制造过程中，不可避免地会出现对使用中的材料做一些更改的情况。经验表明，可采用某些便宜材料作为替代品。然而，在大多数情况下，在进行生产以后改换材料要比在开始生产前改换材料所花费的代价要高。在设计阶段做好材料选择工作，可以避免多数这样的情况。在生产制造开始后出现了可供使用的新材料是更换材料的最常见的原因。当然，这些新材料可能降低成本、改进产品的性能。但是，必须对新材料进行认真的评价，以确保其所有性能都满足要求。应当记住，新材料的性能和可靠性很少像现有材料那样为人们所了解。大部分的产品失效和产品责任事故案件是由于在选用新材料作为替代材料之前，没有真正了解它们的长期使用性能而引起的。产品的责任诉讼迫使设计人员和公司在选择材料时，采用最好的程序。在材料过程中，五个最常见的问题为：（a）不了解或者不会使用关于材料应用方面的最新最好的信息资料；(b)未能预见和考虑擦黑年品可能的合理用途（如有可能，设计人员还应进一步预测和考虑由于产品使用方法不当造成的后果。在近年来的许多产品责任诉讼案件中，由于错误地使用产品而受到伤害的原告控告生产厂家，并且赢得判决）；(c)所使用的材料的数据不全或是有些数据不确定，尤其是当其长期性能数据是如此的时候；(d)质量控制方法不适当和未经验证；(e)由一些完全不称职的人员选择材料。通过对上述五个问题的分析，可以得出这些问题是没有充分理由存在的结论。对这些问题的研究分析可以为避免这些问题的出现指明方向。尽管采用最好的材料选择方法也不能避免发生产品责任诉讼，设计人员和工业界按照适当的程序进行材料选择，可以大大减少诉讼的数量。从以上的讨论可以看出，选择材料的人们应该对材料的性质，特点和加工方法有一个全面而基本的了解。轧辊的挠度轧辊强度计算用的是典型梁弯曲理论。轧辊可认为是一个带有分布载荷的梁，假定轧辊轴承中心为支点和挠度主要是由弯曲力矩和剪切力引起的。因为轧辊直径和辊身长度的比值是非常大的，所以剪切力引起的挠度也算在内。用短的锥形轧辊时，轴向移动时可以减少支撑工作辊的接触长度。这样，横跨钢带宽度的工作辊的挠度可以减小。用这种方法，轧辊不对称的轴向移动能明显地减小钢带宽度方向的平直度的灵敏度。轧辊轴向移动的结果可以通过遍布轧辊支撑面的分布载荷的变化来模拟。轧辊间接触应力两辊之间的支撑压力导致接触点周围产生局部缺陷，沿着水平轴线产生分布的载荷。通过“赫兹压力作用”根据两轧辊之间的接触面挠度的不同来模拟这个分布载荷。轧辊面压痕轧辊间隙的外形受工作辊和钢带接触面间的弹性压痕的不同而影响很大。轧辊压痕模型是以小区域上的单位压力引起的轧辊的挠度为影响因素。总体矫直取决于轧辊和钢带接触面上的小区域的综合影响。抗拉强度平直度、抗拉强度和钢带压力的相互影响导致从轮廓顶部到机架间产生了一个很大的负反馈。由于钢带拉伸引起的载荷的改变可以通过从轧辊压缩到拉伸的灵敏度而得到。钢带压力由于带钢表面缺陷而引起从工作辊到钢带表面横向的载荷分布。综合轧制压力/弧长模型提供精确的轧制力预报。对平直度模型来说，被使用的一个简化的形式是建立在轧制力模型灵敏度的基础上的。对 Sidmar 设备来说，对新来的带钢头部的影响是根据每一个带卷头部在热轧过程中的测量记录来计算的，虽然不太重要，但增加的精确测量在提高头部平直度模型精确度方面起了重要作用。钢带外形在两辊咬合的地方，带钢的的外形取决于缝隙的形状。而外形取决于轧辊挠度、轧辊表面形状和缺口，通过他们各自的几何模型来描述。平直度每个机架间材料的平直度很大程度上依赖于轧制过程中拉伸程度的不同。对冷轧来说，接下来的流程带钢被限制在一个局部的区域，除了这个小区域外，带钢的偏差可以假定为纵向的。出口平直度决定于带钢头部变化和新来的带钢平直度的综合影响。亚结构为减少构造特殊轧制模型，一些标准组件的子系统模型分别被构造。对图 2 中的轧辊来说，一个简单的组件就可以定义作用力影响下的工作辊的挠度。用这个方法，通过轧辊轴向移动和支撑辊的接触长度的共同影响来计算几何灵敏度。这个构件的几何灵敏度数学表达式如下：/2y(x)/2(x,z)dzk(x)Jkg(x)G（1）另一个组件是用来定义工作辊和带钢接触面间的作用力的，它是工作辊挠度、进入带钢的外形和拉伸的函数。/2/2p(x)/2kp(x,z)y(z)dz/2kc(x,z)hin(z)dz/2/2/2ki(x,z)Fin(z)dz/2ko(x,z)out(z)dz（2）这两个组件后来被合成用于轧辊和钢带的复杂模型。六辊和四辊轧机结构用几何形状和组件的知识，机架的大部分组件模型能够被构造，举个例子，如四辊轧机的工作辊的弯曲和轴向移动；六辊轧机的工作辊和中间辊的弯曲执行装置和中间辊的轴向移动。四辊和六辊轧机的模型用相同的方法构造但在六辊轧机的情况下，带有支撑辊和工作辊的中间辊的影响必须被考虑，其平衡条件要和工作辊和支撑辊的一致。Row tandem cold rolling mill models and the flatnesscontrolIn the second half of 1994,Sidmar on the 1st column of cold rolling mill was transformed into a row of five full mill,and equipped with a pickling line.The composition of its mill equipment,including:Screwdown hydraulic rack on the body;with the first-axial movement to the middle of the six roll roller mill;rack all the support roll;final Axial on the rack Mobile work roll.The new cold-rolling technology and this new pickling line to allow the pickling process,the export size and strip mill flatness of the closed-control.It contains two straight measurement system:First,the exit of the mill,and the other is on a rack between the cracks.Flatness through the traditional first-and last a feedback loop between the methods used straight-line model in support of the roll and axial movement set up to control the point.On-line model used to describe 6,4 roller mill axial movement of flatness of linear elements,parabolic and quartic equation.Apart from the straight-degree feedback control and set up online model,a unique feedback system through the strip to confirm the new shape of the type of rack with the flatness measurement to improve the mill exports straightness.The new system all have reached the objective of improving the range of products offered by the flatness quality requirements.Flatness requirementsSidmar rolling mill-650 1880 mm,thick 0.3 3.5 mm and material strength from low-carbon steel to HSLA and in the scope of the carbon steel materials.From the cold-rolled flat-out good for the workpiece can increase production and productivity,it is easy to meet the requirements of the final customer.Typically,the flatness of raw materials from the change to 15 units to go through the entrance to the export line,but according to the residual error and patterns of different wavelengths,the rolling of the roughness is still greatly changed.Sidmar of the mill,in the stable operation of the circumstances,from raw materials to 8 units with volume flatness is the standard performance,better than from raw materials to 11 units,weaker than from raw materials to 5 units.In the new online rolling,rolling with the completion of the volume was shorter,and its new hot-rolled to the 12 volumes between Weld.In this regard,it is the flatness of interference is particularly important,but also for a single feedback system of feedback caused great difficulties.Different sizes of the mill online flatness requirementsPhysical model makes use of the mechanical structure of the most complex flatness model to a basic model was established.This basic model of the physical principles into mathematics and as a module on the code ofprocedure.Module code changes set to be simulated with special machinery to the requirements described in the form of software.For example,if the same model can be set to approximate a graphic description of quadratic equation or linear,quadratic equation and four equations,or for a more detailed set around the strip of 50 units.Sidmar mills online needs of the linear model of the device,secondary and four of the equation.Shape model includes the following modules:Roll the deflectionRoll of contact stressRoll-indentationTensile strengthCoil pressureNewly designs itself can have the question occurrence which many flaws and has not been able to expect,only has after these flaws and the question are solved,can manifest new goods come into the market the product superiority.Therefore,a performance superior product is born at the same time,also is following a higher risk.Should emphasize,if designs itself does not request to use the brand-new method,is not unnecessary merely for the goal which transform to use the new method.In the design preliminary stage,should allow to design the personnel fully to display the creativity,not each kind of restraint.Even if has had many impractical ideas,also can in the design early time,namely in front of the plan blueprint is corrected.Only then,only then does not send to stops up the innovation the mentality.Usually,must propose several sets of design proposals,then perform the comparison.Has the possibility very much in the plan which finally designated,has used certain not in plan some ideas which accepts.How does the psychologist frequently discuss causes the machine which the people adapts them to operate.Designs personnels basic responsibility is diligently causes the machine to adapt the people.This certainly is not an easy work,because certainly does not have to all people to say in fact all is the most superior operating area and the operating process.Another important question,project engineer must be able to carry on the exchange and the consultation with other concerned personnel.In the initial stage,designs the personnel to have to carry on the exchange and the consultation on the preliminary design with the administrative personnel,and is approved.This generally is through the oral discussion,the schematic diagram and the writing material carries on.In order to carry on the effective exchange,needs to solve the following problem:(1)designs whether this product truly does need for the people?Whether there is competitive ability(2)does this product compare with other companies existing similar products?(3)produces this kind of product is whether economical?(4)product service is whether convenient?(5)product whether there is sale?Whether may gain?Only has the time to be able to produce the correct answer to above question.But,the product design,the manufacture and the sale only can in carry on to the above question preliminary affirmation answer foundation in.Project engineer also should through the detail drawing and the assembly drawing,carries on the consultation together with the branch of manufacture to the finally design proposal.Usually,can have some problem in the manufacture process.Possibly can request to some components size or the common difference makes some changes,causes the components the production to change easily.But,in the project change must have to pass through designs the personnel to authorize,guaranteed cannot damage the product the function.Sometimes,when in front of product assembly or in the packing foreign shipment experiment only then discovers in the design some kind of flaw.These instances exactly showed the design is a dynamic process.Always has a better method to complete the design work,designs the personnel to be supposed unceasingly diligently,seeks these better method.Recent year,the engineerig material choice already appeared importantly.In addition,the choice process should be to the material continuously the unceasing again appraisal process.The new material unceasingly appears,but some original materials can obtain the quantity possibly can reduce.The environmental pollution,material recycling aspect and so on use,workers health and security frequently can attach the new limiting condition to the choice of material.In order to reduce the weight or saves the energy,possibly can request the use different material.Comes from domestic and international competition,to product service maintenance convenience request enhancement and customersaspect the and so on feedback pressure,can urge the people to carry on to the material reappraises.Because the material does not select when created the product responsibility lawsuit,has already had the profound influence.In addition,the material and between the material processing interdependence is already known by the people clearly.Therefore,in order to can and guarantees the quality in the reasonable cost under the premise to obtain satisfaction the result,project engineer makes engineers all to have earnestly carefully to choose,the determination and the use material.Makes any product the first step of work all is designs.Designs usually may divide into several explicit stages:(a)preliminary design;(b)functional design;(c)production design.In the preliminary design stage,the designer emphatically considered the product should have function.Usually must conceive and consider several plans,then decided this kind of thought is whether feasible;If is feasible,then should makes the further improvement to or several plans.In this stage,the question which only must consider about the choice of material is:Whether has the performance to conform to the request material to be possible to supply the choice;If no,whether has a bigger assurance all permits in the cost and the time in the limit develops one kind of new material.In the functional design and the engineering design stage,needs to make a practical feasible design.Must draw up the quite complete blueprint in this stage,chooses and determines each kind of components the material.Usually must make the prototype or the working model,and carries on the experiment to it,the appraisal product function,the reliability,the outward appearance and the service maintenance and so on.Although this kind of experiment possibly can indicate,enters in the product to the production base in front of,should replace certain materials,but,absolutely cannot this point take not earnestly chooses the material the excuse.Should unify the product the function,earnestly carefully considers the product the outward appearance,the cost and the reliability.Has the achievement very much the company when manufacture all prototypes.In the manufacturing process,it is inevitable that there will be some changes to the materials used in the manufacturing process.Experience shows that some cheap materials can be used as a substitute.However,in most cases,it is more costly to replace the material before it is produced than to change the material at the beginning of the production.In the design stage to do a good job of material selection,you can avoid the majority of such cases.The most common reason for the replacement of materials is the emergence of a new material that is available after the start of manufacturing.Of course,these new materials may reduce costs,improve product performance.However,it is necessary to carry out a careful evaluation of the new materials in order t