JX03-035@JTK1.2提升绞车滚筒设计
收藏
资源目录
压缩包内文档预览：
编号：490955
类型：共享资源
大小：2.07MB
格式：ZIP
上传时间：2015-11-07
上传人：QQ28****1120
认证信息
个人认证
孙**（实名认证）
辽宁
IP属地：辽宁
30
积分
- 关 键 词：
-
机械毕业设计全套
- 资源描述：
-
JX03-035@JTK1.2提升绞车滚筒设计,机械毕业设计全套
- 内容简介：
-
精密与超精密磨削技术 摘要 : 磨削在现代制造业中占有重要地位，技术发展迅速 ,国内外都采用超精密磨削、精密修整、微细磨料磨具进行亚微米级以下切深磨削的研究，以获得亚微米级的尺寸精度。当前磨削除向超精密、高效率和超硬磨料方向发展外，自动化也是磨削技术发展的重要方向之一。本文就精密和超精密磨削，砂带磨削 ,磨削自动化 进行了研究与论述 . 关键词 : ELID磨削技术 , 砂带磨削 ,磨削自动化 、 Precise and ultra microfinishing technology Abstract： The grinding holds the important status in the modern manufacturing industry, the technological development is rapid, domesticand foreign all uses the ultra microfinishing, the precise conditioning, the tiny grinding compound grinding tool carries on the submicron level to undercut the deep grinding the research, obtains the submicron levelthe size precision.Outside the current grinding except to ultra precise, the high efficiency and the ultra hard grinding compound direction develops, the automation also is one of grinding technological development important directions.This article on precise and the ultra microfinishing, the belt grinding, the grinding automation has conducted the research and the elaboration。 Key word: ELID grinding technology, belt grinding, grinding automation 1 精密与超精密磨削技术 国内外都采用超精密磨削、精密修整、微细磨料磨具进行亚微米级 以下切深磨削的研究，以获得亚微米级的尺寸精度。微细磨料磨削，用于超精密镜面磨削的树脂结合剂砂轮的金刚石磨粒平均直径可小至 4 m。日本用激光在研磨过的人造单晶金刚石上切出大量等高性一致的微小切刃，对硬脆材料进行精密磨削加工，效果很好。超硬材料微粉砂轮超精密磨削主要 用于磨削难加工材料，精度可达 0.025 m。日本开发了电解在线修整 (ELID)超精密镜面磨削技术，使得用超细微 (或超微粉 )超硬磨料制造砂轮成为可能，可实现硬脆材料的高精度、 高效率的超精密磨削。作平面研磨运动的双端面精密磨削技术，其加工精度、切 除率都比研 磨高得多，且可获得很高的平面度 , 在工具和模具制造中，磨削是保证产品的精度和质量的最后一道工序。技术关键除磨床本身外、磨削工艺也起决定性的作用。在磨削脆性nts 材料时，由于材料本身的物理特性，切屑形成多为脆性断裂，磨剂后的表面比较粗糙。在某些应用场合如光学元件，这样的粗糙表面必须进行抛光，它虽能改善工件的表面粗糙度，但由于很难控制形状精度，抛光后经常会降低。为了解决这一矛盾，在 80 年代末日本和欧美的众多公司和研究机构相继推回了两种新的磨削工艺：塑性磨削（ Ductile Grinding）和镜面磨削（ Mirror Grinding）。 (1）塑性磨削 它主要是针对脆性材料而言，其命名来源出自该种工艺的切屑形成机理，即磨削脆性材料时，切屑形成与塑性材料相似，切屑通过剪切的形式被磨粒从基体上切除下来。所以这种磨削方式有时也被称为剪切磨削（ Shere Mode Grindins）。由此磨削后的表面没有微裂级形成，也没有脆必剥落时的元规则的凹凸不平，表面呈有规则的纹理。 塑性磨削的机理至今不十分清楚在切屑形成由脆断向逆性剪切转变为塑断，这一切削深度被称为临界切削深度，它与工件材料特性和磨粒的几 何形状有关。一般来说，临界切削深度在 100 m 以下，因而这种磨削方法也被称为纳米磨削（ Nanogrinding）。根据这一理论，有些人提出了一种观点，即塑性磨削要靠特殊磨床来实现。这种特殊磨床必须满足如下要求： l）极高的定位精度和运动精度。以免因磨粒的切削深度超过 100 m 时，导致转变为脆性磨削。 2）极高的刚性。因为塑性磨削的切削力远超过脆性磨削的水平，机床刚性太低，会因切削力引起的变形而破坏塑性切屑形成的条件。 对形成塑性磨削的另一种观点认为切削深度不是唯一的因素，只有磨 削温度才是切屑由脆性向塑性转变的关键。从理论上讲，当磨粒与工件的接触点的温度高到一定程度时，工件材料的局部物理特性会发生变化，导致了切屑形成机理的变化。作者从实践中找到了支持这种观点的许多证据：比如在一台已经服役 20 多年的精度和刚度不高的平面磨床上磨削 SiC陶瓷，用 40O0#的金刚石砂轮。工件表面粗糙度小于 Rq5 m，表面上看不到脆断的痕迹。另外德国亚琛工业大学的 Konig 教授作了如下试验，在普通的车床上，用激光局部加热一个SiN 陶瓷试件，即能顺利地进行车削。这些实验均间接地说明温度对切屑形成机理有决定性的 影响。 （ 2）镜面磨削 顾名思义，它关心的不是切屑形成的机理而是磨削后的工件表面的特性。当磨削后的工件表面反射光的能力达到一定程度时，该磨削过程被称为镜面磨削。镜面磨削的工件材料不局限于脆性材料，它也包括金属材料如钢、铝和钼等。为了能实现镜面磨削，日本东京大学理化研究所的 Nakagawa 和 Ohmori 教授发明了电解在线修整磨削法 ELID（ Electrolytic In-Process Dressing）。 镜面磨削的基本出发点是：要达到境面，必须使用尽可能小的磨粒粒度，比如说粒度 2nts m 乃至 0.2 m。在 ELID 发明之前，微粒度砂轮在工业上应用很少，原因是微粒度砂轮极易堵塞，砂轮必须经常进行修整，修整砂轮的辅助时间往往超过了磨削的工作时间。 ELID首次解决了仅用微粒度砂轮时，修整与磨削在时间上的矛盾，从而为微粒度砂轮的工业应用创造条件。 ELID(Electrolytic In-Process Dressing)磨削是在磨削过程中，利用非线性电解修整作用和金属结合剂超硬磨料砂轮表层氧化物绝缘层对电解抑制作用的动态平衡，对砂轮进行连续修锐修整，使砂轮磨粒获得恒定的突出量，从而实现稳定、可控、最佳 的磨削过程，它适用于硬脆材料进行超精密镜面磨削。 ELID 磨削技术以其效率高、精度高、表面质量好、加工装置简单及加工适应性广等特点，在日本已较广泛用于电子、机械、光学、仪表、汽车等领域。 ELID 磨削原理是金属结合剂超硬磨料砂轮与电源正极相接做阳极，工具电极做阴极，在砂轮和电极的间隙中通过电解磨削液，利用电解过程中的阳极溶解效应，对砂轮表层的金属基体进行电解去除，从而逐渐露出崭新锋利的磨粒，形成对砂轮的修整作用：同时形成一层钝化膜附着于砂轮表面，抑制砂轮过度电解，从而使砂轮始终以最佳磨削状态连续进行磨削加工。所以该技术将砂轮修整与磨削过程结合在一起，利用金属基砂轮进行磨削加工的同时利用电解方法对砂轮进行修整，从而实现对硬脆材料的连续超精密镜面磨削。 ELID 镜面磨削过程可分为准备阶段、电解预修锐阶段、在线电解修整动态磨削阶段和光磨阶段。准备阶段主要是对砂轮进行动平衡和精密整形，减小砂轮的圆度和圆柱度误差：预修锐阶段使砂轮获得适当的出刃高度和合理的容屑空间，并形成一层钝化膜：动态磨削阶段形成加工表面：光磨阶段则进一步提高表面质量。 ELID 磨削去除材料的机理与其他镜面加工有所不同。通常的镜面加工是通过磨削 、研磨和抛光来获得的。研磨和抛光是以柔性的研磨盘把磨料压在材料表面并产生相对运动，磨料借助研磨盘的压力以滚动方式使材料破碎，以滑动和滚动方式去除破碎后的材料。 而在 ELID 磨削中，一方面由于磨粒固着在结合剂中，对于单颗粒的固着磨粒而言，其有效磨削尺寸只有磨粒尺寸的 1/3，磨粒主要以微切削的方式去除材料，所以造成的破碎区要小得多：另一方面，砂轮表面形成具有一定厚度和弹性且容纳有脱落磨料的钝化膜，成为一种具有良好柔性的研磨膜。精磨时，由于进给量很小，钝化膜的厚度远大于磨料的出刃高度，使砂轮基体表层磨料在磨削中 不可能直接与工件接触，砂轮上覆盖的这层钝化膜将代替金属基砂轮参与真正的磨削过程。当电解作用完全抑制时，钝化膜对工件进行光磨。所以ELID 磨削实际上是一种将磨、研、抛合为一体的复合式精密镜面加工技术，其中磨粒主要是以滑动方式去除工件材料的 ELID 磨削技术是对金属结合剂超硬磨料砂轮在线修整、修锐的复合磨削技术，它有别nts 于电解磨削、电火花磨削，在精密加工领域独树一帜，具有自身的一些显著特点。 磨削过程具有良好的稳定性和可控性，易于实现磨削过程的最优化： 加工精度高，表面裂纹少，表面质量好： 适应性广泛，磨削效率高 ：装置简单，成本低，推广性强等。 ELID 磨削的必备装置主要有砂轮、电源、电解装置、电解液和磨床等五个要素。 ELID 磨削对磨床的要求主要是要有较高的主轴回转精度。 ELID 磨削用砂轮的结合剂应具有良好的导电性和电解性能，而结合剂元素的氧化物或氢氧化物不导电。目前常用的砂轮有铸铁纤维结合剂 (CIFB)、铸铁结合剂 (CIB)和铁粉结合剂 (IB)的金刚石砂轮， ELID 磨削的电源可以采用直流电源、交流电源、脉冲电源等。电解装置的主要部分是工具电极。磨床结构不同，工具电极的位置和形状也不同，电极宜用不锈钢制造 ，与砂轮的间隙控制在 0. 5 1. 5mm 范围内，而且应与机床充分绝缘。工具电极固定在绝缘板上，再用调节栓将绝缘板固定在砂轮防护罩上。电极上开有蓄水槽，电解磨削液采用中心送液法，依靠重力和离心力充满电极间隙。 ELID 磨削液兼做电解液，一般采用弱碱性电解质水溶液。但结合剂和磨粒粒度不同，磨削液的主要成分也不同。磨削液对电解过程中形成的钝化膜的厚度、性质乃至最终的磨削效果都有重要影响。 ELID 磨削技术在我国尚处于研究阶段，主要集中在高校，如哈尔滨工业大学、大连理工大学、西安交通大学、天津大学、西北工业大 学等。哈尔滨工业大学经过几年的努力，研制成功了 ELID 磨削专用的脉冲电源、磨削液和砂轮，在国产机床上开发出平面、外圆和内圆 ELID 磨削装置，并对多种硬脆材料进行了 ELID 镜面磨削的实验研究。目前正积极推广普及该技术，实现产品化。国内已有十几家单位应用该技术，如 230 厂用于加工动压马达零件， 23 所用于相阵雷达互易移相单元陶瓷、微晶玻璃、铁氧体等航天材料零件加工， 8358厂用于光学玻璃非球曲面加工， 205 所用于光学玻璃加工，华侨大学用于加工大理石，福建南安宏伟陶瓷厂用于加工陶瓷等。 尽管 ELID 磨削技术在我国 的发展落后于一些工业发达国家，但是 ELID 磨削技术在国内的研究和应用基础已经具备。特别是该技术显著的特点，尤其适合我国国情。随着该技术的进一步普及推广，相信有越来越多的专家和学者认识到这项技术的重要性和它潜在的经济价值，越来越多的企业重视并采用该技术，从而促进我国传统产业的改造和高新技术的发展。ELID 磨削技术作为一种新型的镜面加工方法，具有广阔的应用前景和很大的实用价值。 nts 精密与超精密磨削技术 摘要 : 磨削在现代制造业中占有重要地位，技术发展迅速 ,国内外都采用超精密磨削、精密修整、微细磨料磨具进行亚微米级以下切深磨削的研究，以获得亚微米级的尺寸精度。当前磨削除向超精密、高效率和超硬磨料方向发展外，自动化也是磨削技术发展的重要方向之一。本文就精密和超精密磨削，砂带磨削 ,磨削自动化 进行了研究与论述 . 关键词 : ELID磨削技术 , 砂带磨削 ,磨削自动化 Precise and ultra microfinishing technology Abstract： The grinding holds the important status in the modern manufacturing industry, the technological development is rapid, domesticand foreign all uses the ultra microfinishing, the precise conditioning, the tiny grinding compound grinding tool carries on the submicron level to undercut the deep grinding the research, obtains the submicron levelthe size precision.Outside the current grinding except to ultra precise, the high efficiency and the ultra hard grinding compound direction develops, the automation also is one of grinding technological development important directions.This article on precise and the ultra microfinishing, the belt grinding, the grinding automation has conducted the research and the elaboration。 Key word: ELID grinding technology, belt grinding, grinding automation 1 is accurate with rubing the technology of paring ultraprecisionly Adopt and waste paring ultraprecisionly, repairing accurately both at home and abroad, it has research that cuts and is rubed pared deeply of under submicro grade that very small abradant is rubed, in order to obtain the size precision of grade of submicro. Very small abradant rub, sharpen, used in ultraprecision surface of the mirror resin sharpened to rub combine pharmaceutical diamond grit of emery wheel average diameter little to 4 m very. Japan cuts out a large amount of and waits for high identical cutting the edge on the artificial single crystal diamond that is ground smallly with the laser, rub and pare processing to the hard fragile material accurately, very effective. Ultra hard material little powder emery wheel ultraprecision to rub, pare, use mainly for, rub, sharpen difficult to process materials, the precision can reach 0.025 m. nts Japan has developed and repaired(ELID) electrolytically online The ultraprecision surface of the mirror rubs the technology of paring, can use ultraly and slightly (or ultra little powder) Ultra hard abradant make emery wheel become, perhaps, can realize hard fragile high precision of material, a high-efficiency one ultraprecision to rub paring. Make level pairs of terminal surface to grind sport accurate to rub technology of sharpening, machining accuracy its, person who excise high much than to grind, and can get very high level degree, in tool and mould are made, it is a process of precision and end of the quality of guaranteeing the products to rub and pare. Technological key besides the grinding machine, rub, sharpen craft play a decisive role. While rubing and paring the fragility material, because of the physical characteristic of material, it is mostly the fracture of fragility that the smear metal is formed, the surface after rubing pharmaceutical is more coarse. , like the optical component, such a coarse surface must carry on the polishing in some application occasions, although it can improve the surface roughness of the work piece, because it is very difficult to control the form precision, will often be reduced after the polishing. And numerous company and research institution of America and Europe push back two rubing crafting of sharpening new in succession for solve contradiction this, doomsday in the 1980s originally: Plasticity is rubed and pared (Ductile Grinding) Rubed and pares (Mirror Grinding) with the surface of the mirror . (1)Plasticity rubs and pares it mainly regarding fragility material, it names smear metal formation mechanism that the source comes from this kind of craft, rub it while paring the fragility material, it is similar to plasticity material that the smear metal takes shape, the smear metal is excised from matrices by the grit through the form of shearing. So this kind rubs way of paring and known as shearing and wasting paring (Shere Mode Grindins) sometimes . Rub surface sharpen, split grade take shape, have fragile yuans of rule must peel off, full of bumps and holes a little, the surface presents regular lamination. Plasticity mechanism sharpened to rub clear in smear metal forming from fragile and broken to shear, change against sex into, mould, break very much so far, all these are pared and known as the borderline to cut the depth deeply, it and work piece material characteristic have something to do with the geometirc form of the grit. Generally speaking, borderline cut depth under 100 m, therefore this kind rub, sharpen method known as nanometer rub and sharpen (Nanogrinding) too . According to this theory, some people have proposed a kind of view, plasticity will be realized by the special grinding machine when being rubed and pared. Such special grinding machine must nts meet the following requirement: l)Extremely high localization precision and movement precision. In case that because result in changing into the fragility and rub and pare when the cutting of the grit exceeds 100 m deeply. 2)Extremely high rigidity. Because plasticity rubs the cutting strength pared exceeds the fragility and rubs the level pared far, the lathe rigidity is too low, will arising from cutting strength deformation destroy plasticity terms that smear metal form. Rub another view pared to show to the plasticity of forming that it is not the only factor to cut the depth, it is a smear metal key from fragility to plasticity transition to only rub the temperature of paring. Theoretically, when the temperature that grit and contact of the work piece are lighted is high to certain extent, some physical characteristic of the work piece material will change, has caused the change of smear metal formation mechanism. The author has found a lot of evidences of supporting this kind of view from practice: For example on active service 20 precision for more than year and rigidity high level grinding machine rub and sharpen SiC pottery already in one, use diamond emery wheel of 40O0 #. The surface roughness of the work piece is below Rq5 m, is outwardly less than the fragile trace that breaks. In addition Konig professor of German Aachen polytechnical university has tested as follows, on the ordinary lathe, heat a SiN pottery with laser part and try one, can carry on turning smoothly. These experiments prove indirectly temperature have decisive influence on smear metal formation mechanism. ( 2) The surface of the mirror is as its name suggests rubed and pared, what it cared about is not but the mechanism that smear metal forms rubs the characteristic of the surface of work piece after paring. When the surface of work piece after rubing and paring reflects all ability and becomes certain, its time to rub the course of paring and known as the surface of the mirror to rub and pare. The surface of the mirror rubs the work piece material pared and does not confine to the fragility material, it includes metal material such as steel, aluminium and molybdenum,etc. too. In order to be able to realize the surface of the mirror is rubed and pared, physical and chemical Nakagawa of research institute, Tokyo University of Japanese, and Ohmori Professor invent electrolytic to repair and rub and sharpen law ELID online ( Electrolytic In-Process Dressing) . The surface of the mirror rubs the basic point of departure pared: Should reach it the border, must enable and use the granularity of grit as small as possible, for example granularity 2 m and even 0.2 m. Before ELID invents, one degree of emery wheels is being employed little commercially in the particle, the reason is that particle one degree of emery wheels is extremely nts easy to stop up, the emery wheel must be often repaired, repair assisting time and often exceeding the working time to pare of wasting of the emery wheel. When ELID settlement for the first time only uses particle one degree of emery wheels, repair and waste the contradiction pared on time, thus create conditions for industry of one degree of emery wheels employ the particle. ELID(Electrolytic In-Process Dressing) It is in the course of rubing and paring to rub and pare, utilize non-linear to repair function with metal combine pharmaceutical ultra hard abradant emery wheel top layer oxide insulating barrier to electrolytic dynamic equilibrium of inhibitory activity while being electrolytic, repair and repair sharp the emery wheel continuously, make the grit of emery wheel obtain invariable outstanding quantity, thus realize steady, controllable, best rubing the course of paring, it is suitable for the hard fragile material and rub and pare the ultraprecision surface of the mirror. ELID rub technology of sharpening until their with high efficiency, precision high, surface of high quality, processing equipment simple processing adaptability characteristic such as being wide, already been used in fields such as electron, machinery, optics, instrument, car,etc. more extensively. ELID rub, sharpen principle whether metal combine pharmaceutical ultra hard abradant emery wheel and power positive pole meet and make positive pole, the tool electrode is made the negative pole, through rubing and paring the liquid electrolytically in the interval of emery wheel and electrode, utilize the positive pole in electrolytic course to dissolve the effect, remove the metal matrices of the top layer of emery wheel electrolytically, thus the brand-new and sharp grit emerges gradually, form the repairment function on the emery wheel: Form membrane of a layer of passivation at the same time and adhere to the surface of emery wheel, it is excessively electrolytic to inhibit the emery wheel, make emery wheel with best to rub, sharpen state rub and pare processing continuously all the time. So this technology repaired the emery wheel and rubed the course of paring to conbine together, ones that utilized the emery wheel of metal base to rub and pare processing utilized the electrolytic method to repair the emery wheel simultaneously, thus realize that rubs and pares the continuous ultraprecision surface of the mirror of the hard fragile material. ELID surface of the mirror rub, sharpen course can divide into preparatory stage, electrolytic to build sharp stage, online to repair, rub the stage of sharpening and only rub stage dynamically while being electrolytic in advance. Preparatory stage mainly carry on the dynamic equilibrium to the emery wheel and have a facelift accurately, reduce one degree of errors of round degree and nts cylinder of the emery wheel: Repair sharp stage highly making the emery wheel get appropriate producing the edge and rational holding space of bits in advance, form membrane of a layer of passivation: Waste the stage of paring and form and process the surface dynamically: Only waste stage and further improve surface quality. ELID rubs and pares the mechanism and other surface of the mirror which removes the material to process to some extent differently. The common surface of the mirror is processed and got by rubing paring, grinding and polishing. It is by grinding one and pressing abradant on the surface of material and producing the relative motion of flexibility to grind with the polishing, abradant makes the material broken by way of rolling through the pressure of grinding one, the material after it is broken to remove by way of slipping and rolling. In ELID rubs and pares, on one hand because the grit is firm in combining pharmaceutical, as to firm grit of the single particle, it rubs and pares 1/3 with grit size of size effectively, the grit removes materials in a manner to cut a little mainly, so the broken district caused is much smaller: On the other hand, the surface of emery wheel is formed to have certain thickness and elasticity and hold coming off the passivation membrane of the abradant, becoming one has grinding the membrane of good flexibility. While finishing grind, because it is very small to enter the giving amount, the thickness of the membrane of passivation is far greater than producing edge height of abradant, make emery wheel base body surface layers of abradant in rub sharpen, keeping in touch with the work piece directly while being impossible, the passivation membrane that cover with at the emery wheel replace metal base emery wheel participate in real rubing the course of sharpening. When electrolytic function is totally inhibited, the membrane of passivation only rubs the work piece. So ELID rubs and pares in fact that one kind will rub, grind, throw the complex type process technology of accurate surface of the mirror united, among them the grit mainly removes the work piece material by way of slipping ELID rub, sharpen technology to combine to metal pharmaceutical ultra hard abradant emery wheel repair, build sharp complex rub the technology of sharpening online, it is electrolytic to rub, sharpen for it to different from, e
- 温馨提示:
1: 本站所有资源如无特殊说明，都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
2: 本站的文档不包含任何第三方提供的附件图纸等，如果需要附件，请联系上传者。文件的所有权益归上传用户所有。
3.本站RAR压缩包中若带图纸，网页内容里面会有图纸预览，若没有图纸预览就没有图纸。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 人人文库网仅提供信息存储空间，仅对用户上传内容的表现方式做保护处理，对用户上传分享的文档内容本身不做任何修改或编辑，并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容，请与我们联系，我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
人人文库网所有资源均是用户自行上传分享，仅供网友学习交流，未经上传用户书面授权，请勿作他用。
川公网安备: 51019002004831号