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包装真空机结构设计【说明书+CAD】,说明书+CAD,包装,真空机,结构设计,说明书,CAD
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本科学生毕业设计包装真空机结构设计系部名称: 机电工程学院 专业班级: 机械设计制造及自动化 08-1班学生姓名: 指导教师: 职 称: 二一二年六月The Graduation Design for Bachelors DegreeThe infusing liquid system of the product line of acid vegetable automatic packing LineCandidate:Li YingSpecialty: Mechanical Design Manufacture & AutomationClass: 08-1Supervisor:Lecturer. Ma WuxueHeilongjiang Institute of Technology2012-06Harbin摘 要近半个多世纪以来,随着生产与流通日益社会化、现代化,产品包装正以崭新的面貌崛起,受到人们普遍重视。本设计主要目的是实现酸菜加工的自动化。其间介绍了灌装机的概念、种类。主要是针对酸菜自动包装生产线注液系统进行的设计主要通过对机械设计的学习、了解和掌握,来确定酸菜自动包装生产线注液系统的各个组成零件并最后组装。通过计算和结构优化设计,决定采用气泵为动力源,以气缸的往复运动及两个单向阀的反向安装来实现酸菜自动包装生产线注液系统的吸液和注液,从而实现由比较简单的结构完成要求的目的。设计后的酸菜自动包装生产线注液系统具有结构简单、紧凑、制造和维修容易、操作简单,成本低。广泛用于中小型食品生产企业。关键词:气泵;气缸;单向阀;电池换向阀;行程开关;贮液缸;自动控制ABSTRACTWith the socialization and modernization of the production and circulation since more than half a century,products packing is flourishing with a completely new feature and attached importance widely.The main purpose of this design is to realize the automatization of acid vegetable processing. It introduces the conception and category of the filling machine. The design aims at the infusing liquid system of the product line of acid vegetable automatic packing. We confirm every part of the system and install it according to the study of machinical design. We decide to use the air pump as the power fountain and realize sucking liquid and infusing liquid by the reciprocating of air urn and the reversed setting of two mon-return valves after calculating.Consequently,we achieve the purpose with a more simple configuration.The infusing liquid system of the product line of acid vegetable automatic packing have simple configuration,. It is tighten and easy to produce, mend and handle .Also it cost low .It is widely used in small and middle food manufactories.Key word: air pump;air urn;mon-return valve;eleceromagnetism cross valve;limit switch;stores the fluid cylinder;auto control目 录摘 要IAbstractII第1章 绪 论11.1 课题背景11.2 课题目的与意义11.3 我国食品和包装机械的发展现状31.3.1 食品和包装机械工业初具规模31.3.2 基本形成了为食品加工业提供成套装备的能力31.3.3 在部分领域形成了大型关键单机生产制造能力31.3.4 我国食品和包装机械工业与发达国家还有较大差距31.4食品和包装机械近期发展重点领域和方向4第2章 灌装机62.1 灌装机概述62.2 国内饮料灌装机械的发展概况62.3 液体灌装设备的分类72.4本章小结8第3章 注液系统的总体方案93.1 注液系统的工艺方案93.2 注液总体原理示意图93.2 动力源的选择93.4 注液系统的传动方案103.5 本章小结.10第4章 系统各部分组件的计算及选用114.1 贮液缸的选用114.2 单向阀的选用114.3 双作用双活塞杆气缸计算及选用124.4 耗气量计算154.5 活塞杆直径校核164.6 气缸的运行速度174.7 换向阀的选用184.8 行程开关的选用194.9 管道的选择194.10 方向控制装置204.11 气动控制部分204.12 本章小结21第5章 框架结构的设计225.1 固定板的设计225.2 外框架的设计225.3 储液箱的设计225.4 本章小结23结 论24参考文献25致 谢26附 录A27附 录B35第1章 绪 论1.1 课题背景随着国民经济的发展和人民生活水平的提高,我国食品工业得到快速发展,已经成为我国国民经济的支柱产业。2002年食品工业总产值达到10554亿元,占全国工业总产值10%左右,食品工业的利税总额占全国工业部门利税总额的20%左右。居全国各产业部门之首。食品和包装机械行业作为食品工业提供装备的工业,形成于20世纪七十年代末与八十年代初,经过八十年代的快速发展,九十年代的高速增长,目前已进入结构调整、产品质量升级、提高创新能力的关键时期。2002年食品和包装机械全行业总产值近400亿元,已成为机械工业系统十四大行业之一,初步满足了我国食品工业的需要。包装机械化的重意义现代包装的基本含义是:对不同批量的产品,选用某种有保护性、装饰性的包装材料或包装容器,并借助适当的技术手段实施包装作业,以达到规定的数量和质量,同时设法改善外部结构,降低包装成本,从而在流通直至消费的整个过程中使之容易储存搬运,防止产品破损变质,不污染环境,便于识别应用和回收废料,有吸引力,广开销路,不断促进扩大再生产。本文研究的是自动包装机生产线的注液系统。大量事实表明,实现包装的机械化和自动化,尤其是实现具有高度灵活性(或称柔性)的自动包装线,不仅体现了现代生产的发展方向,同时也可以获得巨大的经济效益。1.2 课题目的与意义 无论在国内或国外,包装工作已涉及到各行各业,面广量大,对人民生活、国际贸易和国防建设都带来深刻的影响,甚至在现实生活中出现了过去准以想象的新情况:未经包装出售的商品变得越来越少了,而且包装上的失败往往会使很好的产品得不到成功的销售。因而不妨这样说,在将来,如果没有现代化的包装就没有商品的生产和销售;可是如果没有先进的工业与科学技术的综合发展,也不可能出现高水平的现代化包装。迄今,一些科学技术发达的国家,在食品、医药、轻工、化工、纺织、电子、仪表和兵器等工业部门,已经程度不同地形成了由原料处理、中间加工和产品包装三大基本环节所组成的包装连续化和自动化的生产过程,有的还将包装材料加工、包装容器成型及包装成品储存系统都联系起来组成高效率的流水作业线。再者,为使包装成品更好地进入流通领域,大都配有专用的自动化仓库,并采用托盘集装箱运输。(如图1.1所示的现代化酒厂自动包装线的工艺流程简图就是一个颇有代表役的例子。)图 1.1 现代化酒厂自动包装线的工艺流程简图(1)能增加花色品种,改善产品质量,加强市场竞争能力。现代包装机械所能完成的工作已远远超出了简单地模仿人的动作,甚至可以说在很多场合用巧妙的机械方法包装出来的成品,不论在式样、质地或精度等方面,大都是手工操作无法胜任和媲美的。随着商品的多样化,这一点越来越引起了人们的重视。另外,用机械手代替人手,就足以最大限度地避免操作人员同产品直接接触时可能产生的感染,从而保证食品、药物的清洁卫生和金属制品的防锈防蚀。(2)能改善劳动条件,避免污染危害环境。对有剧毒、刺激性的、低温、潮湿性的、爆炸、放射性的,以及必须放置在暗室中的物品,实现了包装的机械化和自动化便可大大改善操作条件,避免污染危害环境。至于对需要进行长期、频繁、重复的以及其他笨重的包装工作,如能实现机械化和自动化,则能大大减轻体力劳动强度,增进工人健康和提高生产效率。(3)能节约原材料,减少浪费,降低成本。有些粉末、被体物料在手工包装过程中容易发生逸散、气泡、飞溅现象,若改为机械包装则会大大减少损失。(4)能提高生产效率,加速产品的不断更新。机械包装的生产能力往往比手工包装提高几倍、十几倍甚至几十倍,无疑这格会更好地适应市场的实际需要,合理安排劳动力,为社会多创造助富。由此可见,实现包装机械化和建立现代包装工业,乃是关系到国家长远规划的一件大事,也是搞好社会主义四个现代化的一项重要内容。1.3 我国食品和包装机械的发展现状1.3.1食品和包装机械工业初具规模目前我国食品和包装机械生产企业达6000余家,其数量在世界各国中居第一位,产品品种3000多种。2002年全行业总产值395.36亿元。其中年产值500万元以上生产企业1133家,2002年产品销售收入345.16亿元,其余4000多家为小型企业,其中近一半为兼营企业。2002年食品加工和包装机械出口交货值2.61亿美元,其中包装机械出口交货值1.38亿美元,开始走向世界。1.3.2 基本形成了为食品加工业提供成套装备的能力食品工业的发展,促进了食品加工和包装机械工业的发展。食品和包装机械的发展又为食品工业的发展提供了重要的装备保障。初步形成了以大学工艺基础研究、院所技术创新和工程转化应用技术开发、企业产品生产制造的分工协作产业发展体系,在一批产品加工领域形成了企业为主体的关键单机生产制造能力和以院所为主体的工程成套装备能力。1.3.3在部分领域形成了大型关键单机生产制造能力近10年有几百项较高技术水平加工设备相继问世并投入生产,达到国外20世纪80年代末90年代初水平,个别机型达到世界先进水平。微波技术、速冻技术、真空技术、膨化技术、超微粉碎技术、微胶囊技术、二氧化碳超临界萃取技术等高新技术已逐步应用到食品加工装备中。1.3.4我国食品和包装机械工业与发达国家还有较大差距我国食品与包装机械工业起步晚、基础差,目前达到或接近世界先进水平的加工装备仅占全部的5%10%;整个行业落后2025年。每年还需要进口大量的食品和包装机械,以满足我国食品工业之需要。技术创新和工程转化能力十分薄弱我国绝大多数食品加工和包装机械制造企业属于中小企业,基本上不具备自主研发能力;由于科研投入不足,研究院所和高等院校的实验条件不完善,造成我国市场上的产品主要还是仿制、测绘或稍加改造的国产化,产业主体技术依靠国外,有自主知识产权的产品少,与世界上食品和包装机械工业强国相比相差甚远,整体技术水平落后2025年。在工程转化和技术集成方面还没有形成有效的产、学、研结合机制,在低水平上各自为战、重复引进、重复研发的现象相当普遍;工艺研究、装备开发、生产制造相互脱节,工程成套及工程转化能力弱。产品结构与质量、性能有待改善我国食品和包装机械行业目前存在的主要问题可归结为五多五少,即:单机多,成套少;主机多,辅机少;技术含量低的产品多,高技术、高附加值、高生产率的产品少;初加工设备多,深加工设备少;通用机型多,特殊要求、特殊物料加工的机型少。产品性能与国外同类产品相比,生产能力低、能耗高。较好的产品小时生产能力仅是国外先进水平的1/2,能耗成倍地高于国外先进产品水平,尤其是大型设备性能差距更大,致使国内大型生产线基本都从国外引进。产品质量方面,存在着工作稳定性、可靠性差,造型落伍,外观粗糙,基础件和配套件寿命短等问题。只有少数产品制定了可靠性标准,无故障时间比国外先进水平的同类产品低得多,仅是它们的1/21/3。企业规模小、布局不合理在企业规模方面,一是集中度不高,二是人均劳动生产率低。我国食品和包装机械工业,从企业数量看还不少,有6000余家,比食品和包装机械工业强国都多,其中有近2000多家不够稳定,每年有近15%的企业转产或倒闭,但又有15%的企业加入这个行业。产值及销售额超过亿元的企业仅有十几家,最好的企业产值和销售额刚过10亿元,上市企业仅有一家;年销售额过3000万元的企业仅有50家,这50家企业的总销售额仅有80亿元,集中度仅达到20.66%。多数企业年产值在几百万到一千万之间,低于100万的企业为数还不少。人均劳动生产率多数企业在10万人民币以下。布局上,我国食品和包装机械工业生产企业主要集中在浙江、江苏、上海、山东、广东、辽宁、北京和河南等省市,上述8省市生产企业占全国食品和包装机械工业总数的64%,而西北地区的甘肃、宁夏、青海和新疆4个省区生产企业只占总数的0.8%,分布极不均衡。1.4食品和包装机械近期发展重点领域和方向加快发展食品和包装机械的技术创新速度,推动产品结构、企业结构和技术结构的调整。选择食品工业中主要行业的技术装备,如大豆加工设备、玉米加工设备、马铃薯加工设备、油料加工设备、乳品加工设备、肉类加工设备、果蔬保鲜与加工设备、饮料加工设备、方便食品和功能性食品加工设备、水产品深加工、食品包装机械、 食品和包装机械共性技术和设备等“重点突破”,依靠技术创新,结合技术改造和关键技术引进与消化吸收,提高食品工业装备的自动化水平,向多品种、成套化、大型化方向发展。第2章 灌装机2.1 灌装机概述液体灌装是包装的重要组成部分,主要包括在食品领域中对啤酒、饮料、乳品、白酒、葡萄酒、植物油和调味品的包装,还包括洗涤类日化、矿物油和农药等化工类液体产品的包装。液体灌装机械有相当一大部分用于食品行业,尤其是饮料制造业。2.2 国内饮料灌装机械的发展概况饮料港装机械是伴随饮料工业的产生而产生,并追随饮料工业的发展而进步的。1809年美国研制出玻璃瓶灌装机;1902年市场上出现酒装番茄酱的压力灌装机;1912年发明了皇冠盖封口机;不久集灌装和封口于一体的灌装压盖机问世;在20世纪末,啤酒酿造业发达的德国制造出手动啤酒酒装和压盖机。含气饮料的酒装工艺难度大,酒装设备的发展大约经历了三个阶段。第一阶段是1952-1957年间,完成了含气饮料灌装机由差压灌装向等压灌装的过渡,采用的是机械阀。第二阶段是1957-1979年,这期间首先是德国HK公司,之后是法国和前苏联,发明研制了等压弹簧阀。弹簧阀在等压状态下,借助弹簧力将充液阀打开,破瓶后充液阀可自动关闭,这样不仅使滔装机酌控制机构简化,而且延长了灌装阀的有效工作时间,为灌装机的高速化创造了条件。弹簧阀的出现是液体等压灌装发展史上的一个重要阶段,至今等压灌装机仍普遍采用弹簧阀只是功能更完善,结构更加合理。第三阶段是以德国SEN公司发明的电动阀为标志,电动阀中气阎和水阀的开启和关闭由可编程控制器控制,对灌装时间、灌装速度进行严格和可靠地界定。我国饮料递装机械制造业起步晚,20世纪60年代前基本上是空白,当时国内啤酒厂和汽水厂都是使用美国和日本20世纪3040年代的设备,工艺落后,机械陈旧,严重影响了我国啤酒和饮料工业的发展,1967年我国才开始研究和生产灌装机械。进入20世纪70年代我国先后引进了一些国外灌装生产线,在装备一些饮料生产企业的同时也促进了我国包装机械行业进入了一个新的发展时期。机械、轻工、军工等领域的一些企业开始在仿制和消化吸收国外技术的基础上,开发了各种中小型的灌装机械,提供给国内一大批饮料厂,促进了我国饮料业的发展。进入20世纪80年代,我国采用技术贸易结合的方式,引进德国SEN公司20000瓶h的啤酒灌装线和日本三菱公司18000瓶h的含气饮料灌装线的制造技术,到1991年又引进了德国KHS公司36000瓶h的啤酒灌装线及生产技术。这样,我国不仅能够生产中小型的灌装机,而且开始生产大型灌装机,技术水平上了一个台阶,将我国液体灌装设备制造业的整体水平提高到一个新的水平。2.3 液体灌装设备的分类表2.1 液体灌装设备分类表分类方法灌装机机型主要特点按灌装阀灌装原理分类等压式灌装机用于啤酒,碳酸饮料及其他含气饮料的包装,也可以灌装不含气饮料负压式灌装机用于不含气饮料,酒类灌装灌装阀很少有滴漏现象常压式灌装机容积定量,重力灌装。用于酒类,乳品,调味品及矿物油,药品,保健品等化工类产品灌装,液损很小压力式灌装机用于不含气饮料的液面灌装,灌装速度较快,无液损容积式压力灌装机背压式灌装,定量准确并可调节,用于植物油,洗涤类日用化工产品等低粘稠液体灌装称重式定量灌装机用于饮料原浆,酒类,药品和植物油等要求定量准确液体的灌装,称量方法有电子称和机械称两种按灌装阀排列形式分类直线式灌装机间歇式步进输送,适用于特殊形状包装容器,大容积的液体包装,生产效率较低回转式灌装机由直线式灌装机发展而成的普通形式,高速连续工作,生产效率较高按包装容器分类玻璃瓶灌装机包装含气或不含气液体的等压,负压,常压压力灌装机聚酯瓶灌装机包装含气或不含气饮料,乳品,植物油,调味品,洗涤类日用化学品等液体的等压,负压,常压压力灌装机金属二片易拉罐灌装机包装啤酒,碳酸饮料等含气液体的等压灌装金属三片易拉罐灌装机包装果汁,素菜汁,植物蛋白饮料等不含气液体的常压灌装机复合纸包装灌装机无菌包装,灌装乳品,果汁,素菜汁等不含气饮料按包装容器的封口形式分类皇冠盖压封灌装机包装含气或不含气饮料冠形瓶,玻璃瓶封口塑料盖压封灌装机包装不含气饮料,瓶盖为撕开式塑料防盗盖塑料盖拧封灌装机包装含气或不含气饮料,塑料防盗盖为抓盖拧封铝质扭断盖压纹封口灌装机玻璃瓶或塑料瓶螺旋口的铝制盖压纹封口,用于含气或不含气饮料灌装易拉罐二重卷边封口灌装机包装啤酒,含气饮料或果汁,植物蛋白饮料的易拉罐等压,常压灌装三(四)旋盖旋封灌装机广口玻璃瓶封口,用于包装果汁,果酱类产品锡箔热封灌装机容积式灌装,乳制品塑料包装的封口软木塞压封灌装机干葡萄酒软木塞封口,负压或常压灌装压塞-塑料盖拧封灌装机洗涤类日化产品包装,复合封口方式锡箔热封-塑料盖拧封灌装机乳制品类饮料包装,复合封口方式2.4本章小结灌装机是针对液体包装的,主要在食品领域中,所以灌装机在包装机械中占重要地位。我国的罐装机械制造业起步晚,随着我国科技的进步,并吸收国外先进的技术,我国的灌装机有了整体的水平提高。 液体的罐装设备可以根据不同的工作原理、排列形式、容器、封口形式分为各种罐装设备。认真了解、分析液体包装生产设备的工作原理、方法,为进一步设计酸菜自动包装生产线注液系统提供模型。第3章 注液系统的总体方案3.1 注液系统的工艺方案注液系统的工艺方案该系统的工艺方案为:吸液贮液注液注液完返回吸液,其具体分析如下:首先该系统的工作方式为往复式的,即在吸液和注液之间使用行程开关来控制执行机构的行程。完成吸液和注液过程,所需的液体通过进给系统将液体输入储液箱,储液箱的液位控制器自动控制液面的高度。但需要工作的时候液体在自重和大气压强的作用下进入注液系统的管道,经动力源作用将其注入食品包装袋里,这样往复运动。注液和吸液这两个动作分别进行,不能互相干扰,即吸液只能从储液箱中吸取,注液只能往包装袋中注液,通过安装两个相反的单向阀来实现。3.2 注液总体原理示意图图4.1 注液原理图3.3 动力源的选择目前,市场上常见的动力源主要有:电动机、汽油机、柴油机、液压马达、气轮机和气动马达。因为液压马达的结构复杂,汽油机的各项成本较高等因素,在农用机械的应用领域之中,较多使用电动机和柴油机作为动力源。考虑到本设计要加工的物料基本上归属于食品行业的生产原料,为了减少污染的来源,所以选用电动或者气动作为动力源。初步计划选用低压气泵(0.4MPa)为动力源。3.4注液系统的传动方案 传动方案:该系统的传动系统为:电机带动气泵将气压能传递给减压阀,调到0.4Mpa压力进入管道,在经电磁换向阀进入气缸的左腔,推动活塞杆向右运动,液体在大气压强和自重的作用下经单向阀流入贮液缸中,贮液缸为液压缸。由于安装单向阀1,不能倒吸液体。但吸液动作完成后,活塞杆压下行程开关a1,电磁换向阀换向,气泵的气压作用与气缸的右腔,与上一动作相同工作实现注液过程。 选用这样的方案比机械式的传动方案结构简单、紧凑,性能优越,能到达工作的要求。3.4本章小结.注液工作原理(1)当汽缸的活塞向右运动时,上边的单向阀关闭,下边的单向阀开启,从而实现汽缸的吸液过程。(2)当汽缸的活塞向左运动时,上边的单向阀开启,下边的单向阀关闭,从而实现汽缸的注液过程。预计结果设计后的白菜包装生产线具有结构简单、紧凑、制造容易,成本低。广泛用于中小型食品生产企业。第4章 系统各部分组件的计算及选用4.1 贮液缸的选用由于系统要求每次注液量在20ml-30ml之间,所以贮液缸的容积应大于30ml。即 ( 4.1) (4.2) 根据上式确定贮液缸的体积和尺寸。采用不锈钢筒,端盖与缸筒之间铆接紧固,轴向尺寸小,外型美观,无给油润滑,使用寿命长等特点。刚好符合抗酸性,体积小的设计要求。具体参数如下:表4.1贮液缸各项参数内径(mm)40动作型式复动型固定型式 LB型使用压力范围Kgf/cm0.051.0保证耐压力Kgf/cm13.5使用温度范围 -25至80(不解冻条件下)使用速度范围 mm/s50700缓冲型式缓冲垫片 4.2 单向阀的选用由于气动系统的工作压力较低,约为0.4 Mpa ,所以选用由广东肇庆方大气动有限公司生产的KA-L6单向阀,其具体参数如下表:表4.2 KA-L6单向阀参数公称通径(mm)6工作压力范围/MPa0.05-0.8环境/介质温度()5-50有效截面积 10开启压力/MPa0.03关闭压力/MPa0.015换向时间/s 0.03泄露量/ 104.3 双作用双活塞杆气缸计算及选用下面来重点研究双作用双活塞杆气缸。从气源出来的压缩空气经减压阀减压后,压力稳定在0.4MPa 。然后,压缩空气经过电磁换向阀后和一个双作用活塞式汽缸相连。如上图所示。当A气缸左腔进气时,活塞杆右伸出,带动贮液缸活塞向右运动,即为吸液过程。当运动25mm后,A气缸右端活塞杆上触点压下行程开关,此时,左腔气体经电磁换向阀与大气相通,排气。当A气缸右腔进气时,活塞杆向左运动,即为注液过程。同样运动25mm后。A气缸右端活塞杆上触点压下行程开关此时,右腔气体经电磁换向阀与大气相通,排气。由于所需推力小,属于高速轻载情况,且气缸安装空间有限,所以决定选用铝合金,不锈钢迷你汽缸。因为汽缸动作时间短,活塞运动速度大,所以活塞杆的直径较粗,现选为d=18 mm,活塞直径选为D=20 mm ,活塞行程根据要求定为 L=25 mm。则活塞腔面积为S1,活塞杆面积为S2 。从减压阀出来的进气压强为P1 。由以下公式可计算汽缸的输出力 (4.3)式中: 气缸的理论输出力, (4.4)大气阻力, (4.5)气缸活塞杆的输出推力,重力加速度10/活塞直径, 活塞杆直径,活塞杆面积, 活塞有杆端面积, 缸筒与密封件表面的摩擦阻力,视加工情况而定, 摩擦阻力因子,工程上常取为0.2气缸的进气压强,大气压强,部分运算结果如下 (4.6) (4.7) (4.8) (4.9) (4.10)现来计算左腔进气的情况,此时右腔排气,接大气,压强为大气压力。此阶段为吸液过程,并可分为以下五个阶段。第一阶段:在汽缸刚启动时,由于气体有压缩性,且气体经过管路和各种阀体到达汽缸的进气腔后,还需要有一定的时间富集,才能克服各种阻力推动活塞向右伸出。此时,气缸的右腔与大气相连,气缸左腔的压力处于持续上升阶段。同时,由于贮液缸活塞未移动,所以,还未达到最大值。公式为: (4.11)第二阶段:经过一定的时间富集后,气缸达到临界状态,气缸活塞虽未移动,但有运动的趋势。此时,气缸右腔与大气相连,无杆腔的压力仍处于持续上升阶段。 (4.12)代入数据为 (4.13) 第三阶段:气缸克服各种阻力作功,拉动贮液缸活塞向右运动。此时,气缸右腔与大气相连,排气,左腔压力达到最大值。公式为: (4.14)代入数据为: (4.15)第四阶段:由于气缸活塞向右伸出,左腔的体积持续增大,致使左腔的压力下降,但活塞依旧向右运动。及下降。公式为: (4.16)第五阶段:贮液缸活塞达到最大伸出量,A气缸活塞右端触点压下行程开关,吸液过程结束。此时,为最大值,并一直保持住,直到电磁阀换向,气缸进入注液阶段。注液过程与吸液过程类似,此时电磁阀换向,右腔进气,左腔排气,接大气,压强为大气压,过程现简述如下:第一阶段:气缸的左腔与大气相连,右腔的压力处于持续上升阶段。贮液缸活塞未移动,所以为零, 还未达到最大值。公式为: (4.17)第二阶段:气缸达到临界状态,气缸活塞虽未移动,但有运动的趋势。此时,右腔的压力仍处于持续上升阶段。公式为: (4.18)代入数据为: (4.19)第三阶段:气缸克服各种阻力作功,贮液缸活塞向左运动,气缸的左腔与大气相连并排气,右腔的压力达到最大值。公式为: (4.20)代入数据为: (4.21)第四阶段:由于右腔的体积持续增大,致使右腔的压力下降,但活塞依旧向左运动。和下降。公式为: (4.22)第五阶段:A气缸活塞右端触点压下,注液过程结束,气缸完成一个往复运动。此时,为最大值73.5,并一直保持住,直到电磁阀换向,气缸进入下一个循环。以上是气缸的一个往复运动的全程分析,气缸在规定时间内究竟需要多少个往复运动由实际生产要求决定,并由事先编好的程序控制。4.4 耗气量计算下面要计算气缸的耗气量Q,并设n为气缸每分钟往复的次数。由以下公式可计算气缸的耗气量。 (4.23)式中 : 代入数值计算得 (4.24)在实际生产中,由于不需要经常变换注液状态,所以该气缸往复的频率很低, n 值不大,因而 Q值也很小。4.5 活塞杆直径校核当气缸带负载工作时,其活塞杆受压缩载荷大,容易引起活塞杆弯曲,因此必须将活塞杆作受压杆来处理,以决定活塞杆的直径和长度。活塞杆的材料为Q235A,屈服极限为216235Mpa,现取最小值216Mpa。当活塞杆的长度H10d时,按强度条件计算,此时活塞杆直径由载荷决定,而与长度无关,或者说活塞杆所受的应力应小于活塞杆材料的许用应力,即 (4.25)故 (4.26)式中 : 代入数值计算 (4.27) d = 18mm 0.6mm ,所以满足设计要求。如活塞杆的长度H10d时,应按纵向弯曲极限力计算,这时活塞杆直径与长度需同时考虑,活塞杆直径不仅和外载荷有关,而且和长度及安装形式及材料的性能有关。4.6气缸的运行速度由于气体的压缩性,且气体需要有一定的时间富集才能推动气缸,所以这段时间设为T1。此时气缸压力持续上升,活塞不运动。在T1点,气缸处于临界状态。当活塞运动后一段时间后,气缸压力上升至最大值,这段时间设为T2。过T2点后,由于进气腔的容积变大,使得进气腔的压力降低,直至活塞达到最大行程,这段时间设为T3。所以,一个循环过程的总时间。T要求小于0.1秒,行程L为32mm,a为活塞缸的加速度。 (4.28)对上式积分可反推出所需时间T。但由于在这三段时间内进气腔的压力一直处于变化中,至使活塞的加速度也处于变化中,如求时间和加速度的二重积分,则因积分曲线过于复杂,而难于计算。所以,现在根据经验公式来估算时间T。如推力取最大值23.7N,则加速度为 (4.29) (4.30)这是理想情况下(即气缸的推力在瞬间就达到最大值并一直保持到活塞运动停止,=1)算出的总时间。为效率因子(值的大小受管路的长度、汽缸的行程、活塞大端面积等因素影响)。值取为0.50.75,代入式(3.14)、(3.15)得T=0.0670.10.1秒,所以满足设计要求。同理可得回程阶段所需的总时间为:,但对回程时间不做要求。根据以上参数要求,具体参数如下表所示:表4.3气缸参数内径(mm)40动作型式复动型工作介质空 气固定型式LB型使用压力范围Kgf/cm0.11.0保证耐压力Kgf/cm1.5使用温度范围 070使用速度范围 mm/s50700缓冲型式缓冲垫片4.7 换向阀的选用因气缸反映速度快,所以要求换向阀动作灵敏,所以决定选用广东肇庆方大气动有限公司生产的型号为Q25DC-6的二位五通电磁换向阀。具体参数如下表所示:表4.4 Q25DC-6型电磁换向阀参数型号Q25DC-6压力范围MPa0.15-0.80公称通径/mm6有效截面积/10工作介质过滤的压缩空气使用温度范围-5-50换向时间/s 0.04工作电压/ VDC:244.8 行程开关的选用本系统采用触点下压的形式实现对换向阀的控制,所以选用由沈阳二一三电器有限责任公司生产的LXW6-11DG型行程开关。具体参数如下表所示:表4.5 LXW6-11DG型行程开关参数型号LXW6-11DG动作力/N3.921.96复位力/N0.49动作行程/mm0.50.2误差/mm0.3 额定电压/VAC380机械寿命/万次100电气寿命/万次1004.9管道的选择包括管子和各种管接头。它把气动控制元件、气动执行元件以及辅助元件等连接成一个完整的气动控制系统。在总气管和支气管等一些固定不动、不需要经常装拆的地方,由于注射液体呈弱酸性,具有一定的腐蚀性,故选用铝塑复合管,该管内外层均为特殊聚乙烯(PE)材料;中间铝合金及胶接PE与铝之间的胶合层组成。烯是一种无毒,无异味的塑料,具有良好的耐撞击,耐腐蚀,抗天候性能。中间层纵焊铝合金使管子不易弯曲不反弹,铝塑复合管拥有金属管坚固耐压和塑料管抗酸耐腐的两大特点。(公称通径为6mm)4.10 方向控制装置由两个单向阀组成,主要控制吸液和注液。如图4-1所示,当主动气缸A向右运动时,从动贮液缸也随之向右运动,左方单向阀关闭,上方单向阀开启完成注液缸的吸液过程;当主动气缸A向左运动时,从动注液缸也随之向左运动,左方单向阀开启,上方单向阀关闭,完成贮液缸的注液过程。4.11 气动控制部分利用电磁力的作用来实现阀的切换以控制气流的流动方向。采用二位五通电磁换向阀及LXW6-11CL型行程开关来完成气缸的连续自动往复工作。如图4-2所示,当按钮a按下后,气缸即不断伸出和收缩回不停工作。当a按下后,自保。在此状态下,行程开关被压下,处于自保使线圈DTA通电,A缸前进伸出。当撞块压下即解除了自保,使A缸缩回。如此往复不停直到停止按钮b按下取消自保方停止工作。图4.6 方向控制装置示意图图4.7 控制原理及电路图4.12 本章小结通过设计计算和校核,选用行程开关,电磁换向阀来控制整个系统的自动运行,以气缸和贮液缸为传动部件,根据设计要求确定其参数和尺寸。先通过工作要求初步选定活塞尺寸和活塞杆的尺寸,然后进行设计计算,并对其校核。第5章 框架结构的设计5.1 固定板的设计采用汤阳县环球工程塑料有限公司生产的UHMW-PE超高分子量聚乙烯硬板。该板具有耐磨损、抗冲击、耐低温、自润滑等优异性能,可长期在110摄氏度至269摄氏度条件下工作,并且吸水率极低有特殊的不 ,对人体无害,是一种性能特别优异的工程塑料材料。具体尺寸为140080020(mm)5.2 外框架的设计 采用建筑用铝合金板。该板强度高、质地轻、表面平整、抗疲劳、抗老化、抗冷热性(温差)能好、抗酸、易安装等特点。结构示意图如下:图5.1 框架结构图5.3 储液箱的设计 箱体材料采用镀锌钢板。其具有抗酸、防锈、防蚀、使用年限长、材质轻、外表美观等特点,是本次设计的理想材料。箱体规格为80040050(mm)。图5.2 箱体结构图5.4 本章小结箱体和储液箱要选用合金钢板,特别是储液箱要选用不锈钢,材料要对人体没有任何危害,不能发生任何污染情况,适应要使连接件能固定牢靠。 箱体和内部结构是紧密相连的结构,设计后的酸菜自动包装生产线注液系统具有结构简单、紧凑、制造容易、操作简单,成本低。结 论本次的研究题目为酸菜自动包装生产线注液系统。该系统的主要特点为自动输入液体、吸液、注液,完成一个动作循环后自动重复运动,可以用于很多包装机的结构中,主要用于食品包装机类。如饮料、啤酒、乳品、调味品等。这个系统具有速度快、无污染、方便快捷等特点。本次设计主要完成了对注液系统的布局、进给系统、传动系统、执行系统的设计计算,并对一些所需部件的运动的选用。该系统选用直立式布局,即进给系统在上、传动系统和执行系统在下,通过气压缸和液压缸取代机械式结构是本次设计的最大优点,可以根据生产要求调节动作循环间的距离增加输入液体量的体积,另一方面,本系统采用电器控制可以完全自动完成工作过程,无需人工过多参与,使得自动化程度更加明显,但是同时,本系统的设计上还有缺陷:本系统的传动采用气压和液压,有泄漏的现象,不精确。解决的方法是提高配合精度,加强密封程度,本系统的发展方向是朝着规模化、自动化、高生产率方向发展,即输入液体吸液注液生产一条线;采用电器控制减少手工操作产生的误差,提高机构的零部件强度,从而提高生产率。从总体上来看,本系统的设计较为合理,安全可靠无污染对人体无味为危害,生产率较高,自动化程度较高,但是,这个系统的细节之处还有未处理好的,这就需要针对本系统进行修改,使其更完美。参考文献1 徐萃平,赵灿,何凡,等.现代机械设计方法与应用M.北京:高等教育出版社,2004.1.2 邹慧君.机械系统设计原理M.北京:科学出版社,2003.4.3 王洪欣.机械设计工程学M.徐州:中国矿业大学出版社,2001.1.4 成大先.机械设计手册(单行本)机械传动M.北京:化学工业出版社,2004.1.5 赵淮.包装机械选用手册M.北京:化学工业出版社出版,2001.4.6 许林成.包装机械原理与设计J.包装机技术, 2006,(02). 7 郑洪生.气压传动与控制技术J.中国机械产业, 2006,(02).8 郑洪生,陆鑫盛.实用气动系统及装置技术J.气压机械,2006,(02).s9 郑洪生,陆鑫盛.气动技术基础J.机械工业, 2007,(02).10 成大先.机械设计手册(单行本)液压传动M.北京:化学工业出版社,2005.111 赵淮.包装机械选用手册M.北京:化学工业出版社出版,2007.412 许林成.包装机械原理与设计指导J.科学技术出版社,2005.9.13 徐莉.气压传动与控制技术J.机械工业出版社,2008.514 郑洪生,陆鑫盛.实用气动系统及装置J.气压机械,2005.515The research J Northwestern Polytechnical University journal that Guan Jiwan rund the systematic Tubemod of process imitation is flex in digitals control such as Yu Suihuai and so on to Zhong Xiadi to He Weiping , 2005 ( 3 ) : 360 364.16Nakamura,Maki S, medium frequency reaction is partly heated to flex the research of the Guan Huidan J application mechanics journal , 2004 ( 6 ) : 81 88.致 谢本次设计的主要内容是酸菜自动包装机的注液机构设计。在设计过程中,由于酸菜自动包装机在我国的设备不多,所以资料不多,给设计工作带来了不少的困难。再者,由于平时所学的书本知识与实际相脱节,使我们在设计中常常感到力不从心,找不到头绪。为此我请教了指导老师马武学老师,马老师给予了我了莫大的帮助,带我们去工厂实习了很多次,现场解说,使我能有的放矢,找出问题的关键。如果没有老师帮助就没有本设计的完成。在此,我向各所有帮助过我的人真心地说一声谢谢你们。并向四年来教导过我,帮助过我的所有任课老师一并致谢,由衷的祝福你们一生幸福。相信在以后的工作学习中,你们的教诲将长伴我左右。我将以你们传授的知识去为祖国的繁荣富强而奋斗。附录A管材弯曲工艺研究新进展摘要管材成形由于容易满足塑性成形产品轻量化、强韧化和低耗高效、精确制造等方面的要求,在航空航天、汽车工业等许多行业中得到广泛的应用。管材弯曲成形工艺的研究是其中备受关注并得到迅速发展的重要领域之一。介绍了几种新的弯管工艺,阐述了国内外弯管工艺的最新研究进展和发展趋势。关键词管材;弯曲;弯管工艺管材塑性加工是以管材作毛坯,通过塑性加工手段,制造管材零件的加工技术1。管材塑性加工由于容易满足塑性成形产品轻量化、强韧化和低耗高效、精确制造等方面的要求,已成为先进塑性加工技术面向21世纪研究与发展的一个重要方向2。在航空航天、汽车、石油化工、轻工及交通运输等工业部门中,广泛地采用管材制造零件。例如在汽车工业中,采用中空铝型材作车身结构和保险杠,在保持与钢铁制件具有同等的抗冲击强度条件下,能减轻30%40%车体质量,对汽车的轻量化具有十分重要的意义;当汽车发生碰撞等意外事故时,管材结构还可以吸收因碰撞带来的冲击能,保护乘客的安全3。管塑性弯曲成形是管塑性成形技术的重要组成部分。用管材制造的弯曲零件,无论是平面弯曲件,还是空间弯曲件,除大量应用于气体、液体的输送管路外,在金属结构中的应用也十分广泛。因此管材弯曲成形工艺是备受关注并得到迅速发展的重要领域,开展这方面的研究工作,具有十分重要的意义。文中介绍了管材弯曲的几种新工艺,以及国内外研究进展和发展趋势。1、基于成形方式的管材弯曲工艺分类实践中有许多不同的弯管工艺,从不同的角度出发可以有多种不同的分类。工程中通常按弯曲时加热与否可分为冷弯和热弯,根据弯曲时有无填充物可分为有芯弯管和无芯弯管。文献4根据不同的成形方式。无模弯曲成形是指管材弯曲变形区不直接受到模具的作用,最终的形状由工具和工件的相对运动决定,属于高度灵活的柔性加工手段。有模弯曲成形是指通过刚性模具直接作用于弯曲变形区而进行的管材弯曲,要求此刚性模具作用部分尺寸可以补偿制件卸载后发生的弯曲回弹,属于可重复性高而且快速的加工手段。2、管材弯曲的几种新工艺2.1热应力弯曲热应力弯曲是一种利用工件内部温度分布不均匀所产生的热应力来驱动工件变形的成形方法。这种方法不需外力作用,因而也不需要专门加工模具,便于现场操作,是一种柔性加工手段,近年来对这种成形方法的研究逐渐增多。加热热源可采用火焰或激光,加热方式包括局部加热及加热炉内整体加热;冷却方式包括空冷、喷水冷却及浸水冷却。具体工艺取决于实际工况和工件特征。激光成形是对局部材料采用激光加热,通过不对称的加热和冷却,一个楔形区域上产生了压缩变形。通过在轴方向不同区域的反复激光照射加热,可以最终确定管材的形状。因为残余应力对制件质量有影响,所以在工艺设计时需要考虑工件的残余应力分布。这种方法由于可以方便地控制激光功率大小和作用轨迹,因此易于成形空间弯曲件。它不仅可以适用于简单的矩形截面管材,而且可以弯曲复杂截面的管材。但是在弯制多型腔型材时有一些限制,且加工时间长,生产效率低文献5提出的管的热应力弯曲方案是:先将管件在加热炉中均匀加热到某一温度,然后以一定速度水平浸入水中,直至管件完全冷却。管件最终凹向后入水一侧,其弯曲规律如下:内外弧的弯曲程度无明显差别;管件截面扁化,其中沿弯曲半径方向的截面尺寸大于垂直弯曲平面方向的截面尺寸,即同压弯法弯管所造成的截面变化趋势相反;管件弯曲程度及截面变化程度随加热温度的提高而增大;长度直径比值较大的管件,其弯曲效果较好。2.2 基于工具运动控制的无模弯曲如图1所示可以通过控制管端夹具轨迹来实现无模弯曲。管端夹具的运动产生的弯曲力矩使得管材在局部区域产生弯曲塑性变形并发生 图1基于管端夹具运动控制的无模弯曲转移。因此可以实现轴向多曲率半径工件的无模弯曲。通过对轨迹的微分方程进行数值求解,可以得到用于弯曲成形设备上的不同的控制程序。文献6使用这种方法成形得到型的零件。另一种通过控制工具运动实现无模弯曲的方法。管材通过一个导向圆柱轴向送料,在离出口一定距离处有一个移动模,其用球轴承作为支撑点,并且可以在垂直于轴向的平面内移动。根据移动模的位置和偏转方向的不同,管材会产生相应的弯曲。通过轴向的进给运动,可以使管材在包括端部的整个长度上进行弯曲。 这种弯曲设备的基本原理是弯曲原理,它可以用来方便地实现管材的空间弯曲,但却必须为各种截面的管材定制不同的模具。图2展示了利用这种成形工艺得到的弯曲管材。2.3叠加法弯曲叠加法的原理3所示当金属材料在塑性区域内变形时,可以利用一个相对于成形力来说很小的侧向作用,实现弯曲。在具体实现过叠加法原理程中,这个很小的作用力可以通过一个偏转轮施加,其产生了一个很小的力矩,影响金属的流动,从而实现了可控制曲率的弯曲加工。由于零件本身是按弯曲要求生产的,因此可以避免产生诸的截面变形、破裂或起皱问题。叠加法最直接的应用就是管材的挤压生产。实际直型材在挤压过程中由于在挤压模中存在不理想的摩擦条件,因而产生了非常小的摩擦力,引起轻微弯曲现象;反过来说,如果在挤压过程中有效控制这个力,利用其使挤压金属的流动速度产生速度梯度,从而实现制件弯曲。另外通过改变摩擦力作用长度也同样可以产生类似的效果。该工艺的优点是可以比较灵活地控制偏转轮而不必改变挤压模具的设计,甚至复杂的多型腔横截面的型材也可以通过这个方法弯曲。目前开展的大多是平面内常曲率弯曲的研究8,对于空间变曲率弯曲从理论的角度上来说是可行的,但是由于需要对偏转轮的实时控制,因此设备方面还需要进行重大改进。另一个类似的弯曲工艺把叠加法原理运用到扩管设备中。2.4数控机床绕弯绕弯是指将管材夹紧在弯曲模上,随弯曲模一起转动,当管材被拉过压块时,压块即将管材绕弯在弯曲管上,属于成形模弯曲工艺。传统绕弯工艺多是手工绕弯,效率低,质量难以保证。随着数控机床业的发展,采用先进的数控弯管机床实现绕弯工艺,可以大大地提高生产效率,保证产品的质量。由于可以方便地调节工艺参数,因此数控弯管机可以既准确又稳定地完成弯曲、送进、转角等动作,保证了管制件的弯曲准确度。数控弯管机可以自动连续地成形不同曲率半径的空间弯曲件。结合相应的数据库软件系统,控制程序还可以预先修正弯曲回弹量。但是该工艺的模具结构(见图4)比较复杂,制件质量对工艺参数敏感,要求有充分的前期准备和试制工作。尤其是对于弯制薄壁管制件的情况,如果工艺参数选择不当,则很容易出现起皱现象导致零件甚至是模具的报废。如何高效准确地获取这些工艺参数,充分保证弯管产品质量,是数控绕弯工艺的研究热点。3、管材弯曲研究进展上述介绍的新弯管工艺多数属于柔性加工手段,拓展了管料弯曲加工的工艺方法范围。实际生产中弯管工艺往往易产生如图5所示的质量缺陷。(1)在弯曲变形区外侧壁会产生壁厚变薄;(2)在弯曲变形区内侧壁会产生壁厚增大起皱;(3)横截面形状畸变;(4)回弹问题。为了解决上述质量缺陷,目前国内外学者对管材弯曲的研究,主要集中于两个方面:通过理论解析和试验研究的方法对弯管的机理进行研究;通过数值模拟的方法对弯管质量缺陷进行研究并改进工艺。在试验研究方面:通过实验研究,分析了牛角芯棒热推弯管成形过程瞬时应力、应变状态及其演化过程,阐明了弯管成形时的受力、变形特点,揭示了弯管成形过程所遵循的力学原理及其分析求解方法,为牛角芯棒热推弯管成形理论研究奠定了基础。根据弯管加工理论、实验研究和大量实践,总结出了对管材弯曲加工成形精度有重要影响的回弹、伸长和成形半径等参数的确定方法,并可用智能弯管测量仪测取上述数据,以用于指导生产。文献7采用能量原理分析截面变扁率和材料性质及工艺参数之间的关系,理论和实验结果吻合得较好。提出的系统建立了系列数控弯管机床的几何、运动、变形、调试及干涉测试的总体仿真模型和完整的模具库及导管库。该系统采用数控指令驱动,能直接从弯管数据库中读取程序,进行装夹、弯曲、回弹等数控弯管全过程的三维动态显示,并可进行干涉检测处理。对中频感应局部加热弯管在不同钢管材料及规格、不同弯曲半径及弯曲角度等工艺参数时的加载和卸载的力能参数、应力应变进行了理论分析和实验研究。在数值模拟方面:提出了中频感应局部加热弯制大直径钢管的回弹理论,计算结果与有限元模拟结果以及实际弯制的钢管弯头实测的回弹量吻合良好。文献8对管材弯曲时的截面变形作了研究和数值模拟,研究表明截面的变形会明显地减小弯曲力,因此在有限元模拟时,会严重地影响力和截面变形的计算结果。文献9采用商用有限元软件对矩形截面管材弯曲作了数值模拟,在起皱、外侧塌陷、截面变形等方面模拟结果和实际情况相符合。在全面分析无模弯曲成形工艺过程的基础上,对该种工艺过程的复杂边界条件作了合理的处理,建立了无模弯管有限元分析模型,开发了可用于管材弯曲分析的三维刚塑性有限元程序,可预报管材(型材)弯曲后断面畸变的情况,有重要的实用价值。此外,对于管材加工中的起皱现象,虽然涉及因素多、研究难度大,但是由于对精确成形的日益迫切的要求,也引起了国内外学者的关注,发表了一些对管材起皱机理的分析和数值模拟方面的研究报道:文献对管材缩口及轴向压缩过程用分叉理论和弹塑性有限元法进行了起皱的预测,分析了单元尺寸、模具尺寸和材料性能对分叉点的影响;对中空矩形铝管的弯曲起皱进行了预测,对低刚度和高刚度两种材料的皱曲波形进行了描述,并采用能量法分别计算了两种材料起皱的临界应力值;在分析讨论国内外关于板材起皱研究的基础上,提出了采用最小能量法预测薄壁管弯曲成形过程中失稳起皱的新思路;采用商用有限元软件 模拟了数控弯管过程,研究发现管材和防皱块之间的间隙是影响起皱的重要因素,同时随着弯曲半径的减小,截面畸变率和壁厚减薄率将会变大。随着计算机技术的发展和有限元软件算法的改进完善,采用数值模拟的方法对实际生产进行模拟是一种被证明是行之有效并且具有很大潜力的途径。采用计算机进行模拟仿真,可以大大地减少试验的工作量,减少时间和人力物力消耗,并且可以方便地改变工艺参数,以系统探索工艺参数对成形的作用和影响。管材弯曲的研究工作方法,也越来越多的由解析试验方法向数值模拟方法转变。但是,由于管材弯曲建模的复杂性,不能简单地用轴对称或平面模型描述。研究人员在进行解析和数值建模时,为了降低三维计算工作量,通常都提出了一些假设前提,这使得研究结果和实际生产出现不小的差距。目前对普通壁厚管料弯曲的模拟的研究比较完善,但是对于薄壁管易压缩失稳出现起皱的情况,还是不能准确判断和正确处理,因此这方面的研究也是管料弯曲研究领域的热点。对于弯曲回弹问题,试验方法取得一定进展,建立了一些基础参数数据库,但是试验工作量非常大,如何用数值模拟方法研究回弹问题,依然是一个难点,有待进一步发展。4、结语(1)管塑性加工由于容易满足塑性成形产品轻量化、强韧化和低耗高效、精确制造等方面的要求,在航空航天等许多行业中得到了广泛的应用,因此管材弯曲工艺备受关注并得到了迅速发展。(2)基于成形方式的分类是管材弯曲的一种新的分类方法。热应力法和基于工具运动控制的无模弯曲可以实现柔性制造;重叠法具有避免产生截面变形等缺陷的特点,可以直接生产弯管制件;数控绕弯可以进行高效批量化生产,符合现代化生产的需要。(3)国内外对于弯管的研究工作,主要集中于试验研究和数值模拟两个方面。数值模拟方法被证明是一种行之有效并且具有潜力的研究方法,对弯管质量缺陷的研究工作越来越多地采用了有限元模拟方法。对管料弯曲建模、薄壁管弯曲起皱和弯曲回弹的研究正成为国内外研究关注的热点。气体的压力作用下喷射到冷却板上,合金凝固后可获得具有细小等轴晶粒组织的坯料。该坯料可用于半固态成形加工用的坯料。这一方法在制备大过共晶铝硅合金等特殊材料的坯料方面有一定的优势,但成本较高。(4)控制结晶过程及晶粒细化法。该方法是通过对合金液体加入晶粒细化剂或控制冷却速度等,以使合金凝固后的固相晶粒不为枝晶状而为非枝晶状(近似等轴晶)。由于这种方法在几种坯料生产方法中成本最低,因而具有较大的发展前途。1.2半固态成形用设备(压力机)目前欧洲、美国及日本等国已生产出专门用于半固态加工的成套设备(压力机),也可以在现有压铸机或锻压设备的基础上改造。半固态加工时温度的控制半固态加工的温度是该加工工艺的主要参数之一。这是因为该温度决定了液相和固相的比例,它对零件加工时所采用的压力以及获得零件的强度、健全性都有重要的影响。目前多采用热电偶、超声波等方法测控。半固态加工用的模具半固态加工用模具的设计可参考压铸模、冲压模等的设计,但必须考虑半固态加工的实际条件。和压铸相比,半固态坯料的温度低,流动时间短,呈层流状;和冲压相比,半固态坯料的流动性远高于固态且成形压力低。有研究表明,半固态加工所用的冲压力仅为传统锻压方法的1/5左右。由于冲压力的降低,对模具材料的要求也降低,可以用非金属材料(如陶瓷、石墨等)制作模具。在发达国家,半固态加工的模具设计多采用计算机模拟设计。已用于半固态成形的铝合金最早用于半固态成形的为亚共晶铸造铝合金(356,357)。这两种合金在发达国家采用半固态成形已实现工业化生产。后来,他们又开发了过共晶成分的390铝硅合金。这种合金中的初晶硅相,在电磁搅拌生产坯料的方法中,被细化并均匀地分布在合金中,提高了合金的强度和耐磨性。有关锻铝合金用于半固态成形加工的技术正处于研究开发阶段。铝合金半固态成形技术的发展趋势铝合金的半固态成形加工主要用于汽车工业中零件的生产。而汽车工业持续要求降低车体重量和减少环境污染,这就要求半固态成形技术能提供高强度的铝合金以替代钢和铸铁制零件等。因此,半固态成形加工技术有广阔的应用前景。半固态成形加工技术今后应在低成本制备半固态加工用坯料、成形设备研制、成形模具设计及成形过程计算机模拟以及开发适合于半固态加工用的新型铝合金材料方面进行深入研究。附录BState of the Art of the Bending Process and Research of TubeAbstract: With the characteristic of high efficiency,forming precision and strength/weight ratio product and low consumption,tube froming processes find an wide application in modern industries such as aero-space and automobile.Tube bending process is one of the most important tube forming processes are introduced,as well as advancement and trend of relative research report. Key word: tube ; bending ;bending process Pipe plastic property process is acting as Mao Pi with pipe ,and by means of the plastic property process measure,manufactures the pipe spare parts process technology.Pipe plastic property is processed meeting the light quantification of produce that the plastic property takes shape thanks to easily、High efficiency of powerful with consumes slowly 、Accurately manufactures and so on the respect demand has become the significant orientation 2 to the 21 centuries research and development of well-developed plastic property process technology.Aviation spaceflight is living 、Motor vehicle 、Mineral oil chemical industry 、Widely adopt the pipe spare parts in the industry department such as light industry and communications and transportation and so on.In for instance being living the auto industry empty the mould material in adopting acting as bodywork composition and the bumper ,and is living to maintain having below the same resisted shock intensity term,and be able to eases 30% against the iron and steel finished piece 40%The automobile body quality have the fully significant sense to the light quantification of motor vehicle;When the motor vehicle happen to run into and so on when the unforeseen mishap,the pipe composition still may suck up the shock capacity brought as a result of ruing into,and safeguards the security 3 of passenger.It is the significant component part ruing the plastic property forming technique that tube plastic property crookedly takes shape.In the way of the crooked spare parts of pipe,no matter is crooked on plane , nevertheless crooked in room,except for the greats quantity are used to gas 、Outside the liquid pipeline route,the application that is living in the metal structure is also fully wide-ranging .The crooked forming technology of pipe this respect research work,and have the fully significant sense hence being accepting the significant territory that the concern obtain the swift development in every possible way.Introduced some kinds of fresh technology that pipe is crooked in the script,along with the home and abroad is researched to make progress and development tendency.1 .Based on , forming means crooked technology of pipe is classified That to possess much in the practice distinct flexed runs technology,may possess much kinds of classifications difference through the distinct angle departs .During usually according to crooked heat whether or not to be divided into cold bend and temperature flexing in the project,and having or not the filler may be divided into processing the rush pith to flex the tube to flex the tube during on the basis of crooked with not is not the rush pith.The literature 4 is on the basis of the forming means of difference.Not is not the standard crookedly to take shape is the crooked deformation district of pipe directly is not subjected to the pattern action, ultimate form shape is through means and the work relative movement resolution ,and pertains to highly the agile flexible process measure.It is crooked by means of the stiff pattern direct action to crooked deformation district but pipe that is underway to possess the standard crookedly to take shape,and requires this stiff part of dimensions of pattern action may compensation finished piece down load what afterwards happen the crooked time pellet,and pertains to the tall but also fast process measure of repeatability.2 .Crooked some kinds of fresh technology of pipe 2.1 Warmhearted stress is crooked One kind of temperature of use work inside that the warmhearted stress is crooked is distributes,and the uniform warmhearted stress coming into being comes drive work the person who becomes deformed the forming means.This kind of means does not require the function of outside force,and as a result also not needing the special process pattern,is convenient for the operation at field,and is one kind of flexible process measure,and grows in number one by one to this kind of forming means research in the past few years.Heating the heat source may adopt flame either laser,and heats that the means consists of that the part is heated the heating furnace the entirety to heat;The cooling means consists of that it is cool to empty 、Spouting the water-cooling yet reaches the cooling reted.Concrete technology is decided by actual operational mode and the work feature.It is adopting laser to heat to the part stuff that the laser takes shape,by means of not symmetrical heating and cooling,the wedge form comes into being on the area compresses the deformation,By means of be living.Reversal laser in distinct areas of shaft orientation illuminates to be heated,and may finally fix pipe form shape.For remains stress possess the effect to the finished piece quality,the necessaries are consider that work remains stress distributes when being living the technological design.This kind of means is since may dominate conveniently laser service rate size and the action locus,hence being easy to crooked in forming room.It not merely may be applicable to easy rectangle section pipe,but also may crooked complex section pipe.Yet is living to flex possess some limits when manufacturing the many types of cavity mould material,and process time elder , the production efficiency is later drop. Tube that the literature 5 the is propose crooked scheme of warmhearted stress is:Shall Guan be living in the heating furnace evenly to heat earlier, afterwards with the specified velocity level macerate in the water,and becomes cool completely till Guan up some temperature.Guan finally hollowly enter the water side backward,and such crooked regular pattern is as follows:The crooked degree of inside and outside arc does not there is not the obvious disparity;In immediate future of Guan section in it is more than crooked plane orientation of the uprightness section dimensions along the bending radius orientation section dimensions,with is getting near flexed that the law flexed the section that the tube created to change tendency contrary;Guan crooked degree and section changing the degree and broad with heating the temperature raise;Guan of length diameter ratio,such crooked effect is better.2.2 Baseded on , the means movement control nil standard is crooked May by means of control Guan no standard crooked clamping apparatus locus achieving.Crooked moment that Guan clamping apparatus movement is come into being causes that is living pipe,and the crooked plastic deformation of part area coming into being is complicated by to bear to transfer.Hence the nil standard that may achieve the axial much curvatures radius work is crooked.By means of carries on the numeric value resolution to the locus differential equation,difference that may obtain is used on the crooked forming installation control procedure.The literature 6 employs this kind of means to take shape and obtains S Spare parts of mould.Another kind does not there is not the means that the standard is crooked by means of do means movement achieving.The stuff is send by means of the direction cylinder axial by the pipe,and being living to part from to export surely to possess the standard removing away from the part,such is in the way of the ball bearing as the centre of resistance,moreover may be living that the uprightness in is removed the axial plane inner place.The pipe be able to come into being relevant crooked to the difference on the basis of the place to remove the standard with the yawing orientation.What it is by means of the axial moves forward to the movement,and may cause pipe be living to consist of the entire length of butt to make progress line bend.The fundamental rule of this kind of crooked installation is MOS It is crooked that it may be used for conveniently achieving pipe room,yet have to act as the different sections pipe customization differences patterns to the crooked rule.Opening up before ones eyes utilizes this kind of crooked pipe that forming technology obtain.2.3 The superimpose law is crooked When the metal material is living when becoming deformed inner place the plastic property area,may utilize one relatively with takes shape force Very little cross acting force,Achieve crookedlyBeing living concrete realization passing through superimpose law rule Cheng Zhong,this very little acting force may be bring to bear on by means of the yawing wheel,such come into being one very little moment,effect metal going from place to place,thereby yet achieved the crooked process of control curvature.May avert coming into being that various sections become deformed since the fact that the spare parts in itself are according to crooked demand manufacture、Split either creases the problem.The most immediate application of superimpose law is a pipe press manufacture.The actual upright mould material is living in the press process thanks to being living that the press is the not ideal rub term in the standard,as a result coming into being very much little friction,The crooked appearance is aroused lightly;Saying the other way round , in the press process effectively this force in case being living,such causes going from place to place velocity the metal come into being the velocity gradient to the use,thereby the realization finished piece is crooked.Besides also may come into being equally analogous effect by means of revising friction action length.That the technology strong point is may comparatively agile dominate the yawing wheel but need not revise the press pattern design,and it is crooked that the mould material in even to the extent that complex tranverse section of many types of cavity also may pass this means.The crooked research 8 of constantly curvature that the politically progressive at the moment is for the most part inner place the plane changes into curvature as to the room crookedly being supposed to on theory angle,yet thanks to the fact that the necessaries adjust the yawing wheel real-time control,hence still need to importantly improve the installation.Another analogous crooked technology is utilized the superimpose law rule up enlarged ruing installation.2.4 The APT coils to be flex Coiling to flex is by on the taut crooked standard being living of pipe clip ,adapts to the crooked standard turning in company,serves as pipe has been to be getting near cake hour,is getting near cake soon pipe to coil to flex being living on the crooked tube,and pertains to the crooked technology of forming block.That the handwork coils to flex is coil to flex technology to be mostly that to the tradition,and the effectiveness is later drop,and the quality is difficult to,In the wake of the APT trade development,adopt the well-developed digital control to flex the ruing machine tool achieving to coil flexing technology,and may lift the production efficiency,quality of guaranty produce enormously.Since may regulate conveniently the technology parameter , hence the digital control flexed Guan Ji may be not only accurately but also steadies completed crookedly 、Send 、The crooked degree of accuracy of tube finished piece in the movements such as street corner and so on.Crooked in the room that Guan Ji may continuously take shape the distinct curvatures radius is voluntarily flex in the digital control.Uniting the relevant data bank software system,the control procedure still may be amend crooked time pellet and measure beforehand.Yet that the technology pattern composition is comparatively more complex,it is susceptible that the finished piece quality adjust technology parameter,the demand possess sufficiently earlier days get ready and the development work.Especially manufactures the thin wall tube finished piece situation as to flexing,in case the technology parameter selection is unsuitably,has arise the appearance creased to cause the spare parts even to the extent that is reporting something as worthless of pattern piece easily.How the high efficiency is accurately gained these technology parameters,sufficiently to flex ruing the produce quality,is the digital control coils flexed the technology research heat。3.The crooked research of pipe makes progress Above-mentioned introduction fresh flexed to run the technology majority pertaining to the flexible process measure,and spread crooked process of the Guan Liao technology means limit.Flex in the actual manufacture quality fault runs technology frequently easily to come into being.(1)The breastwork being living outside the crooked deformation district side wall be able t to come into being is thick and changes into slight; (2)The breastwork being living inner place the crooked deformation district side wall be able t to come into being thickly broadens creasing; (3)The section form shape distortion; (4)Go back to play the problem.In order to resolve the above-mentioned quality faul,at the moment a learned man in home and abroad adjust the research that pipe is crooked,and main lumping is to two respects:The means is researched to mechanism flexing the tube by means of what theory analysis and equipment were researched;The means by means of the numeric value imitation adjust to flex to run the quality fault and researches modification technology.The equipment research respect is living:Research by means of the test,and analysis the strong temperature of ox horn rush pith pushing to flex the tube and takes shape the instantaneous stress of process 、The condition meet an emergency reaches such evolution process , and accepting force when flexing the tube to take shape 、The deformation distinguishing feature promulgated to flex the tube to take shape that the mechanics rule that the process was followed reaches such and analyses the resolution means,and pushes to flex the tube in the interest of the strong temperature of ox horn rush pith to take shape that theory is researched the base.Process theory on the basis of flexing the tube、The test is researched and greats quantity carrying out,and summed up out that the pair crooked process of pipe takes shape that the accuracy possess the significant effect pellet going back 、Certain means extending with forming radius and so on parameter,and the usable intellect flexed the tube measurement instrument and fathoms get the above-mentioned data , and in order to be used the direction to give birth to.The literature 7 adopts energy rule analysis section to change into the relationship between flat rate and stuff nature and the technology parameter,and theory and test are kill to coincide better.Propose TUBEMOD The system was establish the geometry that the ruing machine tool is flex in the set digital control 、Movement 、Deformation 、Total imitation pattern and integrated pattern storehouse and conduit storehouse that debug and interference are tested.Ought to systematically adopt the digital control order drive,and be able to directly read aloud get through flexeds the ruing data bank NC The clip is packed to the order 、It is crooked 、Go back the three dimensions dynamics display that Guan Quans process is flex in the digitals control such as pellet and so on , and may intervene the examination to handle.To the medium frequency reaction partly heats flexed the tube to be living distinct steel tube stuff and the standards 、Loading and down load when the technology parameters such as distinct bending radius and crooked angle and so on force capacity parameter 、Theory is analysis and the test is researched is meet an emergency to be underway that by the stress.The numeric value imitation respect is living:Processing the medium frequency reaction partly heats to flex to manufacture the going back to play theory of great diameter steel tube , and the computational solution is simulated result along with practice against the finite element and is flex that the steel tube manufacture bend factor the person who fathoms the amount going back to the pellet coincide well.The literature adjust that the section of pipe when crooked becomes deformed to act as to research and the numeric value is simulated,and researches making known that the deformation in section be able to obviously decrease crooked force , hence being living that the finite element is simulated the hour,gathering seriously computational solution that effect and section become deformed.The literature adopts commercial finite element software MARC The numeric value simulates crooked acting as to pipe in rectangle section , and is living to crease 、Outside sinks 、The respects such as section deformation and so on simulates the result one another to accord with the actual situation.Is living completely analyses not their is not on crooked forming technology process of the standard base,the complex boundary condition to that kind of technology process do the rightful handle,and establish nil standard flexing ruing the finite element analytic modeling,and opened up the usable three dimensions plastic property finite element orders only a short while ago to the crooked analysis of pipe,yet predicts crooked queens of the pipe ( mould material ) section distortion situation,and possess significant pragmatic value.Moreover,as to the creasing appearance in the pipe process,although it is much to relate to the element 、The research difficulty greatly,yet thanks to adjust the accurately forming pressing increasingly demand, also aroused the concern of home and abroad a learned man,and is used some creasing mechanism analysis and the numeric value imitation respect research cover to pipe:The literature shrinks to pipe,and rim and the axial condensation process plastic property finite element method in the way of tee-offs theory and pellet has been carried on the calculation creasing , and analysis the cell dimensions 、Pattern dimensions and stuff the effect to the tee-offs spot of performance ; What it is to middle the emptying rectangle tube crookedly creased the calculation,and has been underway the description to lets drop stiffness and the high stiffness two kinds of stuffs lines tune wave pattern,and adopts the energy method to calculate two kinds of interface stress values that the stuff creases separately;Being living to analysis the discussion home and abroad to crease on the base which researched, and processing to adopt the minimal energy method to forecast that the thin wall tube loses in the crooked forming process firm what creases fresh thinking on plate; Adopt commercial finite element software PAM STAMP the digital control fled ruing the process , and researching discovering pipe and the gap provided against between the lines lump is the significant element that the effect is creased, moreover in the wake of decreasing of bending radius , thick Bao Shuai reduce of section distortion rate and breastwork be able to change into great.Development and finite element software algorithm in the wake of the calculating machine technique improves consummately,and to adopt numeric value imitation means to adjust practice to give birth to simulate is kind being demonstrated is effectual moreover method that have the very great latent capacity.Adopting the calculating machine to carry on analog simulation,and may decrease greatly equipment amount of work,and decreases time and the labor power resource uses up,moreover may revise conveniently the technology parameter , the parameter adjust forming action and effect with system exploration technology.The also more and more transform through the analysis equipment means to the numeric value imitation means the crooked research work means of pipe.But,can not simply depict since crooked model building of the pipe complexity in the way of either plane pattern.Research fellow is living when carrying on analysis and the numeric value model building,and in order to cut down by three dimensions calculation amount of work , wholly processing some usually assumes the prerequisite,and this causes to research result and practice and gives birth to having arise the not little disparity.Research that adjust the crooked imitation of thick Guan Liao of ordinary breastwork is at the moment comparatively improved,yet as to the thin wall Guan Yi compresses losing the situation that the firm emergence is creased,and nevertheless can not accurately decide handing with correctly,hence this respect research also is the crooked research territory heat-point of Guan Liao.As to crooked time pellet problem,the equipment means is acquired the specified progress,some base parameter data bank were establish,yet equipment amount of work is very much great , and how in the way of numeric value the problem is goes back to play in the imitation method study,and as before is a difficulty,and awaits to develop further.4. Knot Tongue (1)Tube plastic property is processed meeting the light quantification of produce that the plastic property takes shape thanks to easily 、High efficiency of powerful with consumes slowly 、Accurately manufactures and so on the respect demand is living in much professions such as aviation spaceflight and so on to obtain the wide-ranging application,hence the crooked technology of pipe accepts the concern to obtain the swift development in every possible way.(2)Based on,forming means classification is one kind of fresh method of partition that pipe is crooked.The warmhearted stress law crookedly as the nil standard based on means movement control may the realization flexible be manufacture;The reduplication law has to avert the distinguishing feature to come into being the faults such as section deformation and so on,and may directly give birth to flexing the ruing finished piece;High efficiency lot manufacture may be carried on in digital control coiling curve,and accords with the modernize manufacture necessaries.(3)The home and abroad is as to research work flexing the tube,and main lumping to the equipment is researched and numeric value simulating two respects.Numeric value imitation means one kind by demonstrates being effectual moreover have latent capacity research means adjust to flex to run quality fault research work more and more adopting the finite element imitation means.To the crooked model building of Guan Liao 、The crooked research creasing with crooked time pellet of thin wall tube is becoming the heat-point that the concern was researched in the home and abroad.Gas pressure spurts on the cooling plank below the action,and the compound metal solidifies afterwards the crystalline grain blank such as may obtaining have tiny and so on.That that blank is usable the blank that appearance formed was employed to semi.This means is living to prepare the serious offence in all glittering silicon compound metal and awaits that the particular stuff blank respect possess the specified preponderance,yet the cost is taller.(4) Control crystal process and crystalline grain are carefully divided the law.That means is by means of accedes to compound metal liquid the crystalline grain is carefully divided that dose either dominate cooling velocity await,and in order to cause the compound metal solidifies queen to solidity one another crystalline grain not to act as glittering shape but act as non- glittering shape ( awaiting a crystalline substance approximately ).The cost is the least in some kinds of blank manufacture means since the fact that this kind of means is living,as a result having the great development future.1.2 Semi solidity the appearance to take shape in the way of installation ( process ) Europe at the moment 、The state nation such as the U.S. and Japan and so on gives birth to out is specially used semi to solidity appearance process complete sets of equipment ( process),and also may be living to reform on now available die-casting engine either the forging and pressing installation base.1.3 Semi temperature when solid the appearance to process control One of the main parameter that semi temperature to solidity appearance process is that process technology.This is for that temperature resolving liquid phase and the admittedly proportion one another , pressure which adopt
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