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jt汽车白车身焊接夹具的结构设计浅谈资料.doc

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4、栖颊丽雌祟疙街糕憋酌汽车白车身焊接夹具的结构设计汽车工业装备是最近兴起并迅猛发展的一个新兴行业。其实在这之前它也存在着,但由于汽车制造厂的车型更换没有现在这么的频繁,种类这么的多样化,且车型更换时变化最大的就是白车身。这就要求其对应的焊装线能跟上汽车车型和种类的变换。在这种情况下突出了焊装线在汽车生产和制造中的作用,使得人们越来越重视它。在汽车焊接流水线上,真正用于焊接操作的工作量仅占30%40%,而60%70%为工件的辅助和装夹工作。因为工件的装夹是在焊接夹具上完成的,所以夹具在整个焊接流程中起着重要作用。在焊接过程中,合理的夹具结构,有利于合理安排流水线生产,便于平衡工位时间,降低非生产用

5、时节降低生产成本。对于具有多种车型的企业,比如说一汽、沈汽、上汽等。如能科学地考虑共用或混型夹具,还有利于建造混型流水线,提高生产效率。为提高我们汽车焊接夹具的设计水平,对汽车焊接夹具原理、结构及设计方法、原则有一个更深入的了解,在此把我自己的一些见解和经验与大家一起探讨。一、汽车焊接工艺特点(一)白车身的材料与结构汽车焊接材料主要是低碳钢的冷轧钢板,镀锌钢板等。它们可焊性好,适宜大多数的焊接方法,但由于是薄板件,因而刚性差、易变形。在结构上,焊接散件大多数是具有空间曲面的冲压成形件,形状、结构复杂。有些型腔很深的冲压件,除存在因刚性差而引起的变形外,还存在回弹变形。这都是在夹具设计构成中应该

6、考虑的问题。(二)焊接方法汽车焊接方法主要有CO2气体保护焊和电阻焊。CO2气体保护焊应用范围较广,且对夹具结构要求不十分严格。主要注意防止焊接产生的飞溅。相应采取的措施有主要有夹具表面镀铜、主要夹紧定位部件包铜皮、加装保护盖板等措施。电阻焊是在汽车白车身焊接中主要采用的一种焊接方法。对夹具要求严格,尤其是多点焊和机器人点焊。要求焊接夹具对工件定位准确,操作方便且焊接牢固可靠。(三)焊接工艺流程汽车焊接的基本特征就是单个零件到部件再到总成的一个组合再组合的过程。从零件到白车身焊接总成的每一个过程,既相互独立,又相互联系,因此组件的焊接精度决定着部件总成的焊接精度,最后影响和决定着车身焊接总成的

7、焊接精度与质量,这就要求相互关联的组件、部件及车身焊接总成夹具的定位基准应具有统一性和继承性,只有这样才能保证最终产品质量,即使出现质量问题也易于分析原因,便于纠正和控制。白车身的焊接过程以流水线生产为主,所以夹具设计应有利于流水线的布置和设计,同时也考虑给生产管理提供方便。(四)可操作性 我们这里讲的科操作性就是指焊接夹具的使用操作是否方便灵活。一台焊接夹具不仅要保证工件的定位准确,夹紧牢固可靠。还要保证操作者能方便的把零件摆放到夹具上定位夹紧,方便的操作焊枪进行焊接,方便的取出工件。我总结为“三个方便”。要实现这三个方便就要从整体去考虑这些要素,不如说操作高度是否合理,焊枪选用的是否合理,

8、上件夹紧的步骤是否合理。对于形状相似不好区分左右的工件是否有防反措施。对于不好焊接的地方是否有焊枪的导向机构。不好放置和取出的工件是否有举升机构。为了方便焊接是否要增加旋转机构等。这都是在设计过程中需要考虑的问题。二、焊接夹具的设计方法与步骤1在设计焊接夹具之前,应首先了解生产纲领、产品结构特征、工艺方法及生产线布置方式,作好充分的准备。参照国内外先进的夹具结构,并结合实际情况确定夹具总体方案。诸如是固定夹具还是随行夹具,机械化、自动化水平是高是低,几种车型主要夹具是否混型共用等。要准备好的工艺文件包括工序卡,技术协议,产品数模,夹具式样书,焊点文件。确定使用那种标准件,那种气动元件以及甲方的

9、特殊要求。2根据焊件结构特点及所需焊接设备(焊枪或CO2)型号、规格,确定定位及夹紧方式(如果有式样书直接按照式样书上的夹紧定位方式即可);同时根据冲压件的工艺特点及后续装配工艺的需要选择合适的定位点及关键定位点。大部分厂家已经规定好了零件定位的RPS孔和RPS面,不需要我们在制定定位基准了。但是大家也一定要了解如何确定定位的基准孔和基准面。3主体机构确定后,便可确定辅助装置。如水、电、气回路,气、液动元件以及覆盖件外部焊点所需保护铜板等。4按照确定好的定位点开始3D设计。定位块要求在定位面的法向右3mm的调整量。定位销要求在与定位孔中心线垂直的平面上有两个方向的调整量。 5在进行夹具的具体结

10、构设计时,应尽可能多的采用标准化元件,或提高自身的通用化、系列化程度。三、焊接夹具的组成、结构及要求汽车焊接夹具通常由夹具地板、定位装置、夹紧机构、测量系统及辅助系统等五大部分组成。6、命名规则(一)夹具底板夹具地板是焊接夹具的基础元件,它的精度直接影响定位机构的准确性,因此对工作平面的平面度和表面粗糙度均有严格的要求。夹具自身测量装置的基准是建立在夹具底板上,因此在设计夹具底板时,应留有足够的位置来设立测量装置的基准槽和基准孔,以满足实际测量的需要。另外,在不影响定位机构装配和定位槽建立的情况下,应尽可能采用框架结构,这样可以节约材料、减轻夹具自重。在甲方没有指定的情况下,夹具的底板采用如下

11、的规格:1、BASE长度在1m以内的,使用厚度16-18mm的板。型钢使用14槽钢。2、BASE长度在1m 2m之间的。使用厚度为2022mm的钢板。型钢使用16槽钢。3、超过2m的使用大于等于25mm厚的钢板。型钢使用20以上的槽钢。4、BASE为焊接结构件。焊接后要进行退火去应力处理。表面要做防锈处理。并且在BASE面内刻线。(二)定位装置定位装置中的零部件通常有固定销、插销、挡铁、V型块,以及根据焊件实际形状确定的定位块等。1因焊接夹具使用频率极高,所以定位元件应具有足够的刚性和硬度,以保证在更换修整期的精度。一般采用45钢。型面要求表面淬火。定位销要耐磨并且有一定的刚度。一般采用40C

12、r调质,表面镀铬处理。压紧部分的要求与定位部件的要求一致。 定位销又分为固定、摆动、伸缩这几种。 当工件上的定位孔的中心线与BASE面垂直(垂直于取件方向),且定位销在工件的下面的时候,采用固定销。当定位销的轴线于BASE面(或取件方向)有角度的时候采用伸缩销。这时如果定位销在工件的上面则采用摆动销。在使用摆动销的时候注意旋转点的选择。原则是以旋转点为中心所画的圆于摆销的中心线相切。如下图:此圆与销中心线相切 2为便于调整和更换主要定位元件及使夹具具备柔性的混型功能,定位机构应尽可能设计成组合可调式的。3标准化设计。按照现有的厂标件的标准统一一些能够通用互换的零件。例如 L座、导向板、调整垫片

13、等。我们也要不断从各个厂家中的标准件中取优去劣,总结出自己的标准件.在这个行业中早早晚晚会有我们自己的行业标准件,因为只有这个统一了才能够使我们这个行业有更大的竞争力.才能向快更好更高的目标发展.4、夹紧机构汽车焊接夹具的夹紧机构以快速夹紧机构(手夹)和气动夹紧机构为主。快速夹紧机构具有以下优点:4.1 快速夹紧器,其结构简单,从自由状态到夹紧状态的角度可以自由的调整,主要用于批量较小生产纲领较低的生产线。在车型前期的试制(样车)时经常使用。4.2 快速夹紧器根据需要可几个串联或并联在一起使用,达到二次夹紧或多点夹紧的目的。另外对定位精度较低的焊件能实现夹紧和定位同时进行,消除了专用定位元件。

14、它还能通过转换其机构组成发挥更多作用,应用范围较广。4.3 配以螺纹调节压块,可纠正焊件变形,保证焊点搭边能紧密配合,不产生脱焊、虚焊现象,提高焊接质量。气动夹紧机构具有夹紧和打开速度快,压紧力量大,定位准确的优点。是现在焊装线普遍采用的一种夹紧方式。用于生产纲领高的大批量生产。使用不同种类的气动元件相互配合就能实现复杂的定位夹紧机构和不同的功能。(四)辅助机构辅助机构在焊接过程中发挥着重要作用。下面介绍三种常用辅助机构。1.旋转系统在夹具底板和夹具支撑中布置的旋转系统,可使夹具体在平面上做360度旋转(为使转动灵活轻巧还配备有滚动轴承)。这样的系统可解决或克服焊机少的缺陷,因为当焊机不动,电

15、缆长度有限时,转动夹具可使焊点移动到焊钳的工作区域进行焊接,使焊接工作方便轻松地进行,保证焊接质量。另外,为保证夹具在装夹、拆卸时能处于稳定工况,还应设计止动装置。2.翻砖机构当焊点处于中间位置时,如果用X型焊钳进行点焊,则焊钳无法伸进,喉深也不够,难以焊接;若用C型焊钳,如果夹具平放,虽能焊接,但工人的劳动强度大。所以设计夹具时,可将其设计成可翻转夹具,使焊件能向两边翻转90度,焊件平面处于竖直位置,这样工人只要将焊枪处于水平位置便可焊接,大大降低了劳动强度。在设计翻转夹具时需要设计止动机构,以防止夹具自动回复原位造成事故。增加配重块移使工人操作时方便省力。3、滑台 使用滑台的目的有以下几种

16、: (1) 在不能够直接夹紧或定位的地方。如下图此处不能直接支撑,用滑台从侧面滑入。(2)多种车型混流时,如下图:滑台滑到此位置时另一车型一种车型(3)总拼夹具中使用滑台把侧围总成与地板总成拼装。(五)测量机构利用夹具本体自身设计测量机构是提高夹具设计和制造精度的重要措施。在传统的夹具设计中,夹具合格的标准是利用实际冲压件进行装配组合来检验的,但由于冲压件不可能十分准确,部件总成更有累计误差,所以车身焊接总成的精度必然不高,很难达到设计要求。即使我们使用三坐标测量仪进行检验,可它对一些结构复杂的定位元件仍然无法测量。通过实践证明,利用夹具自身测量机构与三坐标测量仪配合使用,可大大提高焊接夹具的

17、精度。1.测量机构组成(1)基准面和基准槽。测量机构的基准面为夹具地板的工作表面;基准槽是在夹具地板上设计两条相互垂直的十字交叉槽,其结构如图。槽子的位置可由实际需要确定,但是一定在坐标的整百位上。其形式如下图:直角边为坐标的整数位基准槽基准孔3个四、典型夹具机构特点分析(一)点焊夹具点焊夹具结构简单,可以移动,应以轻巧、灵活为主,定位基准一定要准确。(二)CO2气体保护焊夹具这种夹具一般以固定式为主,其结构简单。但如果一副夹具仅焊一个组件,则效率太低,这时可将其依次或对称设计成几组定位夹紧机构,做到一具多用,以提高焊接效率。(三)综合夹具这类夹具所装夹组件,既有CO2焊,又有点焊。这对一些全

18、点焊组件中有些位置不适宜在夹具上点焊,而一些焊点对外观和质量无特殊要求的焊件,如果用CO2焊先在夹具上预焊,则很方便,且夹具设计简单。所以应适当地进行工艺调整达到简化夹具和提高效率的目的。(四)大型焊接夹具中大型焊接夹具机构庞大、复杂,各部件总成与车身焊接总成之间既相互关联又相互制约和影响。(五)工艺措施与夹具的关系汽车焊接夹具是焊接工艺能否顺利、正确执行的保证,而工艺过程是否合理也影响夹具的设计和使用效果。如因散件装焊次序不同而产生的焊接质量差异等。因此工艺人员和工装设计人员应密切配合,设计出合理的夹具及工艺。(六)调试过程中的再设计对于大型焊接夹具,因结构复杂,调试时会出现许多设计、制造上

19、的问题,以及焊接散件超差等现象。这就要求设计者根据实际情况予以指导修正。调试是一项很复杂的技术工作,而小批量调试和大批量生产又会出现许多不同的问题,因此设计者应随时了解情况,不断地予以修正,在调试过程中再设计。夹具调试还有另一项重要工作,即验证焊接散件是否合格,但调试时应避免因散件质量问题而认为夹具不合格的错误。当然散件有些是属于合理的回弹变形,有些误差也可通过夹具修正成合格品。因此夹具设计者应充分了解冲压件的工艺特性,通过合理的夹具设计,放宽冲压件的合格品范围。六、发展趋势1为提高汽车产量,适应流水线生产,应细化工艺,使用高效率夹具,提高生产效率。2为适应系列车型需要,应发展快速可调的混型夹

20、具。3提高夹具机具一体化程度。4采用新的设计方法,如坐标法、模块化设计法、计算机辅助设计等。5提高夹具通用化、系列化、标准化水平。 温海洋 长春合心焊夹分公司(英文版 ) easily blame, to prevent the broken window effect. Supervise the leading cadres to play an exemplary role, take the lead in the strict implementation of the and , lead to safeguard the solemnity and authority of th

21、e party discipline, ensure that the party discipline and the laws and regulations for implementation in place. Throughout the discipline in the daily supervision and management, strengthen supervision and inspection, from the thorough investigation of violations of discipline behavior. Strengthen to

22、 key areas, key departments and key projects as well as the masses reflect the concentration of the units and departments for supervision. - strengthening supervision, discipline inspection and supervision of cadres to set an example for compliance with the and is a man must be hexyl, blacksmith nee

23、ds its own hardware. Discipline inspection organs as the executor of the party discipline, and supervisor of the defenders, for its supervision must be more strictly, discipline inspection and supervision of cadres to firmly establish the awareness of Party Constitution, sense of discipline and rule

24、s consciousness, politics loyalty, sense obey. Action speak Ji Ordinance to set an example of the regulations of the rule of law, strengthen supervision and accept the supervision of the firmness and consciousness, do comply with and . To firmly establish the discipline must first be disciplined, th

25、e supervisor will be subject to the supervision of concept, and consciously safeguard and implement party compasses party, take the lead in practicing three strict real strict, so loyal, clean, play. To be good at learning, the Constitution and the as morality, politics and brought to fruition; to i

26、mplement , do not want to, dare not, not with disciplinary ruler to supervision; to discipline a ruler, often the control inspection, and consciously in the ideological red line to draw the row Ming Good accumulation is indeed the bottom line, so that the heart has fear, said to have quit, the line

27、has ended. Attached: indifferent to heart, calmly to the table in our life, there are many unpredictable things will happen, some good, some bad things, we cannot control is powerless to stop, but with time, you will find in life sometimes turns out to be not good, some bad things finally turned out

28、 to be a good thing, but then we muddy however did not know, this is the life teach us things. 1, life can be complex, can also be simple. Want simple life of precipitation, to have enough time to reflect, to make Become more perfect. Life is the most important thing is not to win, but the struggle;

29、 not to have conquered, but to have fought well. 2, the plain is the background of life. Live a plain life, give up on themselves is not a coward, but the wise answers; not disillusioned after the heart, such as ashes, but experience the storm after the enlightenment; not unrewarding perfunctorily,

30、but calm attitude of life of unrestrained self-confidence. Plain living, there is no noise noisy, no earthly troubles, more did not fill in the discontent of desire, some just a calm, a calm. 3, memory of heart will not good things to erase the, life is a When no movie, pain is a beginning, the stru

31、ggle is a kind of process, death is a kind of ending. Give up this giving up is the helpless, do not give up the abandoned, do not give up this giving up is ignorance, do not give up should not give up is persistent. 4, a thing figured is heaven, think impassability is hell. Since the living, to liv

32、e better. Sometimes we because of too narrow-minded, too care around the chores and penny wise and pound foolish, not worth the candle. Some things to attract trouble and worry, completely depends on how we look at and deal with it. Dont always take everything back to things, and dont get into a bli

33、nd alley, dont want to face, dont be narrow-minded. Poke to care, is a kind of open-minded, a free and easy. 5, I am not afraid of others behind me a knife, I afraid to look back and see stab me, is my intention to treat people; I am not afraid of the truth to tell the best friend, Im afraid he turn

34、ed to it as a joke to tell dont 6, when we are in a positive frame of mind, you will find many good things; and when we are in a negative state of mind, you will find many depressed things; life happy and worry, all is you of life attitude, optimistic, good luck; loss of sink, Eritrea company. When

35、you are in adversity, may wish to change a point of view to think everything over to the good Think, because good mentality decided the fate of the! 7, people are tired, rest; heart tired, calm. Grow up, mature, this society read. Tired and sad, squat down, to their a hug. Because the world no one c

36、an sympathize with you, have mercy on you. You cry, tears is your own; you pain, no one can understand. Then you only tears to smile. 8, each people have youth,Each youth are a story, the life of the world never gets easier, I want what, wish the world all know, as has been the same; now want anythi

37、ng, for fear that others know, or like to lose the same. 9, the heart move, everything in the world is followed by birth, Rangrang, important thing is often the most difficult to open ones mouth, because words will reduce its importance; to let strangers people care about your life in the good thing

38、s, the original is not easy 10, do not blame, do not laugh at who, also dont envy who. Like a person is a kind of feeling, not like a person is true. The truth is easy to explain, I feel Is unspeakable. The best travel life is that you in a strange place found a long lost touched. 11, happy life not

39、 in the bustling in, and in the peace of mind; no matter how many grievances, how uncomfortable, and ultimately to heal themselves or their own, others may got you to comfort, but never know your heart is how wanjianchuanxin. 12, maam, like a movie, learn to appreciate, learn to be grateful, learn t

40、olerance, and goodness, helping others. Instead of accusing the society, as into one; and an exception is better to give than to what 13, dont envy him A sum of, dont lose your life and the life, respectively is: the former is a we experienced cannot escape in a day finally will last minute, while t

41、he latter is our persistent, we want to cherish the memory of those people and things. 14, learn to smile, learn to strong, the world you know so many people, so many people and you are, you cannot change also cant let everyone like you, so also do not want to do. Life is too short to go crazy to lo

42、ve to go to waste, to chase the dream to regret. 15, when temper, a blessing to go. A wounding elegant people, the key is to control their own emotions. With the mouth is the most stupid behavior. A control negative emotions than a can take a city more powerful water flow slow, language is expensive

43、. People spent two years of time to learn to speak, but to spend a few years time to shut up. That is a kind of ability, that is a kind of wisdom. 16, life is not perfect, sometimes, growth is not a cry, not an eyeful of tears, there is no trace of emotion, there is no gleam of hope, no desire, no a

44、ction, no static, there is only one kind of downward sinking feeling, sink A murky? 6? 7? 6? 7 sink? 6? 7? 6? 7 toward the bottom of the sink. 17, in some way, do not go, you will not know the other side scenery is beautiful. To you is not good, you do not mind too much, no one has an obligation to

45、you; you learn knowledge, is you have weapons, you can start from scratch, but not unarmed; how do you treat people, does not represent how others treat you, if cannot see through this point, only inviting worry. 18, time is like a sponge in the water, as long as you are willing to squeeze, the tota

46、l water is still there. Every life, after the ups and downs The best test of live, to life, survival and continuation, do not stop the struggle in the joys and sorrows of life on the road, so that different soul to bear life beat, acceptance of suffering. 19, indifferent to heart, calmly in table, e

47、legant and comfortable life, do not take what is so important. The pursuit will be disappointed; to be alive, you will have trouble. Life is the most afraid of what all want to care about, but also what all grasp is not firm, without scenery, separated populations, such as not to desire, all docked

48、in the fate of the end. Why is too rigid, the natural, to go stay not to live, let go of obsession, revel is 20, if the fate of the broken Hopes of sailing, please dont despair, the coast is still, if the fate of the withered petals of the beautiful, please do not sink, the spring is still, life will always be endless trouble, please dont helpless, because they are still alive, is still a dream, the sun still, w

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