摩托車凸輪軸生產(chǎn)制造工藝研究
摩托車凸輪軸生產(chǎn)制造工藝研究,摩托車,凸輪軸,生產(chǎn),出產(chǎn),制造,工藝,研究,鉆研
特種加工工藝
人類通過使用工具和智能來制造使其生活變得更容易和更舒適的物品這種方法，把他們自己與其他種類的生命區(qū)別開來。許多世紀(jì)以來，工具和為工具提供動力能源的種類都在不斷地發(fā)展，以滿足人類日益完善和越來越復(fù)雜的想法。
在最早的時期，工具主要是由石器構(gòu)成?？紤]到所制造的物品相對簡單的形狀和被加工的材料，石頭作為工具是適用的。當(dāng)鐵制工具被發(fā)明出來以后，耐用的金屬和更精致的物品能夠被制造出來。在20世紀(jì)中，已經(jīng)有了一些由有史以來最耐用，同時也是最難加工的材料制造的產(chǎn)品。為了迎接這些材料給制造業(yè)帶來的挑戰(zhàn)，工具材料已經(jīng)發(fā)展到包括合金鋼、硬質(zhì)合金、金剛石和陶瓷。
給我們的工具提供動力的方法也發(fā)生了類似的進(jìn)步。最初，是由人或動物的肌肉為工具提供動力。隨后，水力、風(fēng)力、蒸汽和電力得到了利用，人類能夠通過采用新型機(jī)器、更高的精度和更快的加工速度來進(jìn)一步提高制造能力。
每當(dāng)采用新的工具、新的材料和新的能源時，制造效率和制造能力都會得到很大的提高。然而，當(dāng)舊的問題解決了之后，就會有新的問題和挑戰(zhàn)出現(xiàn)。例如，現(xiàn)今制造業(yè)面對著下面一些問題：你如何去鉆一個直徑為2 mm，長度為670 mm的孔，而不產(chǎn)生錐度和偏斜？用什么辦法能夠有效地去除形狀復(fù)雜的鑄件內(nèi)部的通道中的毛刺，而且保證去除率達(dá)到100%？是否有一種焊接工藝，它能夠避免目前在我的產(chǎn)品中出現(xiàn)的熱損傷。
從20世紀(jì)40年代以來，制造業(yè)中發(fā)生的大變革一次又一次地促使制造廠家去滿足日益復(fù)雜的設(shè)計方案和很高耐用度，但是在許多情況下幾乎接近無法加工的材料所帶來的各種要求。這種制造業(yè)的大變革不論是現(xiàn)在還是過去都是集中在采用新型工具和新型能源上。這樣做的結(jié)果是產(chǎn)生了用來去除材料、成型、連接的新型制造工藝。這些工藝目前被稱為特種加工工藝。
在目前所采用的常規(guī)制造工藝中，材料的去除是依賴于電動機(jī)和硬的刀具材料進(jìn)行的，諸如鋸斷、鉆孔和拉削。常規(guī)的成型加工是利用電動機(jī)、液壓和重力所提供的能量進(jìn)行的。同樣，材料聯(lián)接的常規(guī)做法是采用諸如燃燒的氣體和電弧等熱能進(jìn)行的。
與之相比，特種加工工藝采用按照以前的標(biāo)準(zhǔn)來說不是常規(guī)的能源?，F(xiàn)在材料的去除可以利用電化學(xué)反應(yīng)、高溫等離子、高速液體和磨料射流。過去非常難進(jìn)行成型加工的材料，現(xiàn)在可以利用大功率的電火花所產(chǎn)生的磁場，爆炸和沖擊波進(jìn)行成型加工。采用高頻聲波和電子束可以是材料的聯(lián)接能力有很大的提高。
在過去的50年間，人們發(fā)明了20多種特種加工工藝，并且將其成功地應(yīng)用于生產(chǎn)之中。這么多種特種加工工藝存在的原因與許多種常規(guī)加工工藝存在的原因是一樣。每一種都有他自己的特點(diǎn)和局限性。因而不存在一種對任何制造環(huán)境來說都是最好的工藝方法。
例如，有時特種加工工藝或者通過減少生產(chǎn)某一產(chǎn)品所需要的加工工序的數(shù)量，或者通過采用比以前使用的方法更快的工序來提高生產(chǎn)率。
在另外的場合中，采用特種加工工藝可以通過增加重復(fù)精度，減少易損壞工件在加工過程中的損傷，或者減少對工件性能的有害影響來減少采用原來加工工藝所產(chǎn)生的廢品數(shù)量。
由于前面所提到的這些特點(diǎn)，特種加工工藝從其誕生時起就開始了穩(wěn)定的發(fā)展。由于下列原因，可以肯定這些工藝將來會有更快的增長速度：
(1)目前，同常規(guī)工藝相比，除了材料的體積去除率外，特種加工工藝幾乎具有不受限制的能力。在過去幾年中，某些特種加工工藝在提高材料去除率方面有了很大的進(jìn)展，而且有理由相信這種趨勢在將來也會繼續(xù)下去。
(2)大約半數(shù)的特種加工工藝目前采用計算機(jī)控制加工參數(shù)。使用計算機(jī)可以使人們所不熟悉的加工過程變得簡單，因而加大了人們對這種技術(shù)的接受程度。此外，計算機(jī)控制可以保證可靠性和重復(fù)性，這也加大了人們對這種技術(shù)的接受程度和其應(yīng)用范圍。
(3)大多數(shù)特種加工工藝可以通過視覺系統(tǒng)，激光測量儀表和其他加工過程中的檢測技術(shù)來實(shí)行適應(yīng)控制。例如，如果加工過程中的檢測結(jié)果表明，產(chǎn)品中正在加工的孔的尺寸在變小，可以在不更換硬的加工工具(如鉆頭)的情況下，修正孔的尺寸。
(4)隨著制造工程師，產(chǎn)品設(shè)計人員和冶金工程師們對特種加工工藝所具有的獨(dú)特能力和優(yōu)越性的了解的增加，特種加工工藝的應(yīng)用范圍將會不斷增加。
Nontraditional Manufacturing Processes
The human race has distinguished itself from all other forms of life by using tools and intelligence to create items that serve to make life easier and more enjoyable. Through the centuries, both the tools and the energy sources to power these tools have evolved to meet the increasing sophistication and complexity of mankind's ideas.
In their earliest forms, tools primarily consisted of stone instruments. Considering the relative simplicity of the items being made and the materials that were being shaped,stone was adequate. When iron tools were invented, durable metals and more sophisticated articles could be produced. The twentieth century has seen the creation of products made from the most durable and, consequently, the most difficult-to-machine materials in history. In an effort to meet the manufacturing challenges created by these materials, tools have now evolved to include materials such as alloy steel, carbide, diamond, and ceramics
A similar evolution has taken place with the methods used to power our tools. Initially, tools were powered by muscles; either human or animal. However as the powers of water, wind, steam, and electricity were harnessed, mankind was able to further extend manufacturing capabilities with new machines, greater accuracy, and faster machining rates.
Every time new tools, tool materials, and power sources are utilized, the efficiency and capabilities of manufacturers are greatly enhanced. However as old problems are solved, new problems and challenges arise so that the manufacturers of today are faced with tough questions such as the following: How do you drill a 2-mm diameter hole 670-ram deep without experiencing taper or runout? Is there a way to efficiently deburr passageways inside complex castings and guarantee 100% that no burns were missed? Is there a welding process that can eliminate the thermal damage now occurring to my product?
Since the 1940s, a revolution in manufacturing has been taking place that once again allows manufacturers to meet the demands imposed by increasingly sophisticated designs and durable, but in many cases nearly unmachinable, materials. This manufacturing revolution is now, as it has been in the past, centered on the use of new tools and new forms of energy. The result has been the introduction of new manufacturing processes used for material removal, forming, and joining, known today as nontraditional manufacturing processes.
The conventional manufacturing processes in use today for material removal primarily rely on electric motors and hard tool materials to perform tasks such as sawing, drilling, and broaching. Conventional forming operations are performed with the energy from electric motors, hydraulics, and gravity. Likewise, material joining is conventionally accomplished with thermal energy sources such as burning gases and electric arcs.
In contrast, nontraditional manufacturing processes harness energy sources considered unconventional by yesterday's standards. Material removal can now be accomplished with electrochemical reactions, high-temperature plasmas, and high-velocity jets of liquids and abrasives. Materials that in the past have been extremely difficult to form, are now formed with magnetic fields, explosives, and the shock waves from powerful electric sparks. Material-joining capabilities with the use of high-frequency sound waves and beams of electrons.
In the past 50 years, over 20 different nontraditional manufacturing processes have been invented and successfully implemented into production. The reason there are such a large number of nontraditional processes is the same reason there are such a large number of conventional processes; each process has its own characteristic attributes and limitations, hence no one process is best for all manufacturing situations.
For example, nontraditional processes are sometimes applied to increase productivity either by reducing the number of overall manufacturing operations required to produce a product or by performing operations faster than the previously used method.
In other cases, nontraditional processes are used to reduce the number of rejects experienced by the old manufacturing method by increasing repeatability, reducing in-process breakage of fragile workpieces, or by minimizing detrimental effects on workpiece properties.
Because of the aforementioned attributes, nontraditional manufacturing processes have experienced steady growth since their introduction. An increasing growth rate for these processes in the future is assured for the following reasons:
(1) Currently, nontraditional processes possess virtually unlimited capabilities when compared with conventional processes, except for volumetric material removal rates. Great advances have been made in the past few years in increasing the removal rates of some of these processes, and there is no masonto believe that this trend will not continue into the future.
(2) Approximately one-half of the nontraditional manufacturing processes are available with computer control of the process parameters. The use of computers lends simplicity to processes that people may be unfamiliar with, and thereby accelerates acceptance. Additionally, computer control assures reliability and repeatability, which also accelerates acceptance and implementation.
(3) Most nontraditional processes are capable of being adaptively- controlled through the use of vision systems, laser gages, and other in-process inspection techniques. If, for example, the in-process inspection system determines that the size of holes being produced in a product are becoming smaller, the size can be modified without changing hard tools, such as drills.
(4) The implementation of nontraditional manufacturing processes will continue to increase as manufacturing engineers, product designers, and metallurgical engineers become increasingly aware of the unique capabilities and benefits that nontraditional manufacturing processes provide.
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