底座注塑模具設(shè)計,底座,注塑,模具設(shè)計 外文翻譯 系 別 機械工程系 專 業(yè) 機械設(shè)計制造及其自動化 班 級 學(xué) 號 姓 名 指導(dǎo)教師 負(fù)責(zé)教師 外文翻譯 原文： Large, Complex Technical Moulding It's a frequently debated issue: should a custom moulder specialize, whether it be in a certain process, market, or material, or is a generalist more likely to succeed? IMI recently visited Coko Kunststoffwerk in Bad Salzuflen, Germany, to see a company that has most definitely specialized in a type of injection moulded product, and in doing so, has become a solid success. Coko decided to specialize in large parts: housings, panels, cabinets, and other shapes where the shot is measured in kilograms, the flow paths are long, and the moulds weigh multiple tons. When it comes to technology, however, Coko is less of a specialist. Because of the large variety among what we can generally call large parts, Coko has had to master a number of injection moulding technologies. It uses conventional injection moulding, structural foam, two-component moulding including foam-core sandwich moulding, and most recently, gas-assisted injection moulding. The company builds its own moulds in a tool shop designed around producing large and what is increasingly becoming very complicated tooling. Coko is not a newcomer. It began 60 years ago in the plastics business as an extruder. The company grew, expanded into injection moulding, opened the tool shop, and gradually began developing the expertise in larger parts. Injection moulding is the company's only plastics processing focus now. Thomas Schromber, who is Coko's manager of customer support, started our tour in the mouldmaking shop. And he did that very deliberately. Coko strongly believes in being a single source for its clients. The company slogan, loosely translated, says "We give form to your products." Schromber says the customer can come in with an idea, a sketch, or a rough design, and Coko will take it from there. The overwhelming majority come in with solid product designs, but in any case, Coko feels that the mould is the foundation of the entire production process, so it must be perfect. They do send up to 25 percent of their mouldmaking work outside, but only the least complicated moulds, and even then only to toolmakers close-by and well-trusted. Fortunately, Bad Salzuflen is one of those not-so-uncommon islands of the plastics business in Germany, and a number of skilled toolmakers are in the neighbourhood. Making Big Moulds The mouldmaking operation is in a building of 1,400 sq m separate from the injection moulding operations. Two shifts are staffed by 60 craftsmen five and sometimes six days per week. The machining equipment, almost all CNC driven, includes straightforward large-piece roughing stations, small finishing machines, and EDM systems, and culminates in an automated machining station from Makino whose programming includes automated selection and mounting of the proper tool from among 59 in its ready rack. Some 70 percent of the work is done by erosion. Workpieces can be as heavy as 13 tons and as large as 2,000 x 1,500 x 1,000 cm (780 x 585 x 390 inches). A large machine using a very long coring tool was acquired so cooling channels through large mould pieces could be made in a single continuous operation from one side. Eliminating the rotation of the workpiece needed to bore from two sides improved channel accuracy and reduced machining time. Noting the various years that the machines were acquired, Schromber mentioned that Coko accepts continuing investment in new machining technologies as normal. "You absolutely must be current in this business." Mould Design At the back of the machine shop is a door leading to a product display room packed with a wide variety of large parts. Past that is a staircase up to the "Konstruktion" department. In German that word also means design, and this mould design department is as up-to-date as the machining facilities. Coko switched to CAD/CAM systems eight years ago, and today designers are busily working at Silicon Graphics workstations and smaller PCs using both 3-D (Intergraph) and 2-D CAD software. Coko accepts CAD files in all the standard formats and says client files are supplied mostly in 2-D. Schromber noted that for reasons of speed, 2-D is almost always employed at Coko for the shape of the product prior to actually designing the mould. The reason that 2-D files are considerably smaller than 3-D. The computer can incorporate modifications and redraw a design more quickly, so the work goes faster. 3-D, he continued, has become indispensable for today's mould designing because so many of the parts are very complicated. Thick and thin sections with little transition, lots of undercuts and rib patterns ?with and without gas channels ?all making for complex moulds with many core pulls, slides, and unscrewing mechanisms. In addition to the computer hardware, Coko's design group has a number of large drafting tables holding design plots of large moulds in progress. When the designs are complicated and the moulds are big, which is most of the time at Coko, it is difficult to see the whole design and the details simultaneously on a computer monitor. Standing, or more accurately, walking in front of life-size renderings, gives Coko's designers another way to use their experience (they have built more than 7,000 moulds) to catch potential problems. Big Injection Machines Coko has roughly 300 working moulds and 45 injection moulding machines with clamp forces ranging from 60 to 2,000 metric tons. Most are larger than 500 tons and most, along with their robots, are from Battenfeld. Six machines between 200 and 400 tons are from Krauss-Maffei, also equipped with robots. Because Coko changes 12 to 15 of those large moulds each day, the Stabliy quick mould change system was adopted a few years ago. It reduces the average mould changing time by 80 percent. The company's reason for using a 60-ton machine can be summed up in one word: assemblies. Coko has substantially added to its business by providing clients with complete assemblies. The small machines support that capability by making the small parts needed. All machines are gas-assist-ready, and all but the smallest have already run gas-assisted moulds. Coko has been using gas assist for more than six years, but Schromber says product designers are still learning the options gas assist gives and the restrictions it removes. As they learn they naturally create more products that use those advantages. Because of that learning curve and the unique design and function possibilities, not to mention process cost reduction offered by gas assist, Coko sees continued growth in this area. Coko has a central 2 Airmould gas system, consisting of a gas generation unit that extracts nitrogen from the ambient air and a gas pressure control system. It can supply gas to as many as five machines doing rod-type parts or 10 doing flat parts, and the system is expandable as demand grows. To increase flexibility now, Coko uses Battenfeld's Airmould Mono-Module. Compact and wheel-mounted, this gas pressure control unit can be rolled alongside any press in the shop and connected to the preinstalled interface in the machine's controller. Handling the Materials Mix More than 7,000 tons of thermoplastic material are used each year, mostly PP, PS, and PE (stored in five 30-ton-capacity silos) but there is also a high percentage of technical materials including PC, ABS, blends, nylon, PPO, and others, but no thermosets or elastomers. Everything is checked for melt flow index and dryness on arrival. The central material handling system, designed by Coko and supplied principally by Azo with some components from Motan, was installed several years ago. Material blending and feeding is gravimetrically controlled and the system, located logically between the materials storage area and the production floor, has contributed measurably to Coko's overall productivity. Pointing to a stacked collection of full, reusable Gecon containers from GE Plastics, Schromber noted how such seemingly simple things can contribute to productivity. The pallet-mounted containers are rigid and high-capacity, meaning faster, yet more secure handling into and out of storage. When empty, the container structure collapses onto the pallet for return to the manufacturer, eliminating much of the time and money formerly spent on disposal of one-trip containers. Customer Support Technology Walking between two long rows of injection moulding machines, one sees solid moulded shapes, skin-over-foam sandwich moulded panels, two-colour parts, structural foam housings to be plated or painted, and gas-assisted structures that ignore many of the old rules on part shape, flow length, and wall thickness. Is that a bit baffling to a client? Absolutely not, says Schromber. It's not the client's job to select mould and moulding technology, even though the more experienced often have very clear ideas about production from the start. Coko's first step with the customer is to look at the performance specifications for the part or assembly. The important thing here is the application of know-how. The choice of injection technologies depends on far more things than the physical dimensions of the part. How does the part function? What are the critical performance requirements? What is its competition in its market? What are the projected quantities, and the cost parameters? They search for anything to give the client an advantage. Gas-Assist Advantage Coko began using gas-assist technology six years ago. Having decided to enter that field, they found expertise at the Institute for Kunststoffverarbeitung (IKV), The Institute for Plastics Processing that is affiliated to RWTH, the University of Aachen, Germany. That plastics think-tank, some 500 persons strong, was already well into the subject and had a large knowledge base. Schromber, who is a University of Aachen graduate, joined Coko at about the same time. The affiliation with IKV continues as a working relationship for Coko. Gas assist is an area where expertise acquired through hands-on experience is critical. IKV, for example, has produced a remarkable video that shows the gas-assist process as it is occurring inside the mould. It first had to make a mould with a transparent window. What one learns in the video can be summed up simply: gas does not always do what you logically think it would. Very often it does not travel symmetrically through a part, even a symmetrical part, and the video clearly shows this. Coko was also involved in the production of the video. Schromber says that Coko now almost always injects gas directly into the mould rather than through the nozzle. If gas flow is not symmetrical and you send it through the nozzle, the gate will most likely have to be off center. The mould would have to be mounted off center on the platen, bringing you face-to-face with loss of platen parallelism. Coko frequently uses multiple gas injection ports to precisely control distribution of the gas pressure, taking advantage of hot runner technology to have custom-positioned gates. Also, the timing of the gas into those ports is often sequenced. There is, however, a way to decide where to position the gas ports and gates and how to sequence and pressurize them Prototyping and Simulation Most of us agree that prototyping and mould simulation is good policy before cutting metal on any mould. When a mould is going to be as large as Coko's normally are, with the correspondingly large investment, Coko feels there can't be too much prototyping and simulation. If the client doesn't provide a product prototype, Coko turns to one of several nearby companies with stereolithography (STL) facilities. Prototype moulds can be made internally in a shop that regularly produces aluminum production moulds for its structural foam parts. When it comes to moulding simulation, Coko again uses its affiliation with IKV to advantage. IKV has developed and commercialized its own mould design software package, Cadmould-3D, which includes extensive mould simulation. IKV and Coko create as many simulations as they need to be totally sure of the design. The payoff from the simulation is a lot more than positioning gas ports and nozzles. Using Cadmould, IKV provides Coko with a full set of baseline processing parameters for the machine: temperatures for the mould and the material, injection pressure, holding temperature, pressure and time, and more. As much as Coko benefits from this extensive preparation, its clients benefit more. The flat panel for a Canon copier shown above proves the point. Formerly, the part had been made in Japan of painted structural foam. There were sink marks opposite the mounting bosses and other thick sections, and the overall quality level was not what Canon wanted. So Coko changed it to a solid part with gas assist. The painting cost was immediately eliminated. Average thickness was reduced by half. So was the overall weight, and along with it, the material cost. The cycle time went from more than three minutes in foam to less than 90 seconds for the part shown. And those quality problems are history. These "more than just plain moulding" projects don't appear by chance. To secure them, Coko has built an extensive assembly operation that includes inserts and outserts, ultrasonic and vibration welding, screen and pad printing, hot stamping, and a complete painting facility that includes EMI shielding. What doesn't take place in house, such as metallizing, can be done by someone in the neighbourhood. Coko is offering its customers a single point of responsibility for large, complex parts and supplying the know-how to give the customer significant benefits. The formula is working. 13 譯文： 龐大而又復(fù)雜的模具 行內(nèi)人士經(jīng)常討論這樣的一個話題: 是否要制定一個模具工的規(guī)范呢,一個只精通某個過程，市場或材料的人與一個通才哪一個更有可能成功呢?為了尋找答案，IMI 最近拜訪了德國Bad Salzuflen的Coko Kunststoffwerk,看到了這樣的一家公司，它在注射模具產(chǎn)品生產(chǎn)中幾乎都制定了明確的規(guī)范,并且該做法取得了相當(dāng)大的成功。Coko 決定專門制造大的產(chǎn)品:比如殼，嵌板，櫥柜和其他如填料需要用公斤來計算的,流道很長而且模具重達(dá)幾噸的零件。然而，當(dāng)提到技術(shù)的時, Coko并不能完全稱得上是一個專家。因為在我們通常稱呼大的零配件有許許多多的樣式，Coko 必須精通大量的注射模塑技術(shù)。他們使用傳統(tǒng)的注射模具，結(jié)構(gòu)性泡沫，和包括夾有泡沫塑料核的復(fù)合式注塑模具,以及最近使用的氣體輔助注射模具。 Coko 也并不是一個新手。它在60年以前以塑料生意起家。然后公司慢慢成長,擴大了注射模具,開辦了工具中心，而且逐漸地開始在較大的零配件中開發(fā)專門技術(shù)。 注射模具現(xiàn)在是該公司加工塑料的唯一焦點。Coko公司的客戶支持部經(jīng)理Thomas Schromber讓我們從模具加工中心開始參觀。很明顯這是他故意安排的。 Coko 強烈地相信它的客戶就是一個單獨的財源。公司口號簡單地翻譯就是 " 我們把形狀給你的產(chǎn)品 "。Schromber說，客戶能帶來一個方案，一個草圖, 或一個大致的設(shè)計，而且 Coko將會從中采納一些。一般來說，絕大多數(shù)設(shè)計是實體產(chǎn)品的設(shè)計，但是無論如何，Coko 感覺模具是整個的生產(chǎn)過程的基礎(chǔ)，因此，它一定要完美。他們把25%的模具制造送到外面加工，只留下最不復(fù)雜的鑄模，而且僅僅只給那些值得信賴和高技術(shù)的技工加工。值得一提的是，Bad Salzuflen 在德國并不只是該行業(yè)中如此不尋常的一員，而是有許多大的加工公司也和他們一樣。 制造大的模具 模具制造是在一間1,400平方米的車間內(nèi)并和注射模具注射車間分開。二個錯模就夠60個工藝員每個星期工作五天有時候甚至是六天。而機器的設(shè)備幾乎都是CNC驅(qū)動,包括筆直而又大的原料工作臺，小的修整機器和EDM 系統(tǒng), 以及一臺來自Makino的極品自動機器工作臺，它有包括自動選擇和能從有59個工具的工具庫中取出合適工具的裝置，70% 的一些工作是由沖蝕來完成的。 工件可能是像13噸一樣的重和大得如 2,000 x 1,500 x 1,000 cm.(780 x 390 x 585英寸)大小尺寸，該大機器需要空心裝置以致于冷卻通風(fēng)管貫穿整個大的模具工件，這樣就可以單獨地從一面連續(xù)地操作了。鉆孔加工中的鐵屑要準(zhǔn)確地從兩個側(cè)槽排除并且要盡量減少加工時間。在注意到不同年數(shù)的機器時，Schromber提到了Coko在新的機制技術(shù)方面接受連續(xù)的投資的事很普通。"你絕對要走該行業(yè)的前列"。 模具設(shè)計 在加工中心的后面是一扇通到一個被裝滿各式各樣的大零配件的產(chǎn)品展覽廳的門。過去那只是通往"Konstruktion"部門樓梯口。在德國語中那一個詞也是設(shè)計的意思，而且這一個鑄模設(shè)計部門像機器設(shè)施一樣的先進(jìn)。Coko在八年前就轉(zhuǎn)換到電腦輔助設(shè)計/ 電腦輔助制造系統(tǒng)了，而且今天設(shè)計者正在忙碌地在矽圖形學(xué)工作站和使用安裝了3-D(Intergraph) 和2D的電腦輔助設(shè)計軟件的較小PC機。Coko接收各種標(biāo)準(zhǔn)格式的CAD文件并且大部分的客戶都只提供2D的圖形文件。 Schromber注意到影響速度的理由,2-D的圖表在Coko為模具設(shè)計生產(chǎn)最先被使用。原因是2D的文件比3D的占的內(nèi)存小得多。小型計算機就能更快組合和修正而且很快地可以重畫一個設(shè)計，因此，工作也很快。不過他繼續(xù)提到3-D已經(jīng)對今天的鑄模設(shè)計變得不可缺少了，因為大多數(shù)的零配件非常復(fù)雜。比如厚的和小的組件之間的過渡，許多模型凹腔和肋的薄斷面樣式 、有或沒有氣體通風(fēng)槽、所有制造復(fù)雜鑄模拉桿，滑塊，和鎖緊裝置。 除了計算機硬件之外，Coko設(shè)計組有若干個大的草繪工作臺,并把大模具分割成幾部分進(jìn)行繪制工程圖。在Coko大部份的時間內(nèi),設(shè)計都很復(fù)雜而且模具都很大，這樣就難以在一個計算機上同時地見到整個的設(shè)計和細(xì)目。這樣就需要在整體尺寸的繪制之前繪制的標(biāo)準(zhǔn)化件或很精確的零件圖.這也給了Coko設(shè)計者們另外的一個方法來使用他們的經(jīng)驗(他們已經(jīng)建造超過7,000個模具)去發(fā)掘潛在的問題。 龐大的注射機 Coko大略有300個工作的模具件和45個夾緊力在6到2000噸范疇內(nèi)的注射機。 大部分的注射機的夾緊力超過500噸并且大多數(shù)是裝配了Battenfeld生產(chǎn)的機器人。 有六臺來自Krauss-Maffei的機器是在200和400個噸之間，不過也裝備機器人。因為Coko每天變更那些大的鑄模中的12到15個, 穩(wěn)定而又快的模具變換系統(tǒng)已被采納多年了。它能減少平均80% 的平均鑄模變換時間。 公司使用一部 60噸的機器理由總結(jié)為一個詞: 組合。Coko實質(zhì)上已經(jīng)充分地擴展到提供完整的裝配給客戶了。小的機器也用于制造小的零配件需要。 所有的機器是氣體輔助裝備,而且?guī)缀蹙退闶亲钚〉亩加袣鈩虞o助的鑄模。雖然Coko使用氣體輔助裝置已經(jīng)超過六年了，但Schromber仍然說產(chǎn)品設(shè)計者正在學(xué)習(xí)如何選擇更好地使用氣體輔助裝置和限制它的不利因素。當(dāng)他們學(xué)會了他們就能利用這些優(yōu)勢自然地生產(chǎn)出更多的產(chǎn)品。因為這樣可以學(xué)習(xí)曲線和獨特的設(shè)計以及功能可能性,更不用說氣體輔助能減低生產(chǎn)成本，Coko好像要在這一個領(lǐng)域中繼續(xù)發(fā)展。 Coko擁有一個在中央有2個空氣模具的氣體系統(tǒng)，它有一個可抽取來自周圍空氣中的氮氣和一個氣壓控制的氣體產(chǎn)生機構(gòu)，它提供的氣壓可為多達(dá)五臺機器去做桿類的零件或十臺去做平面的零件，而且這個系統(tǒng)可根據(jù)需要來擴張它的功能。為了增加工作的靈活性，Coko使用Battenfeld的空氣模具的單一模具，組件等，該氣壓控制機構(gòu)在車間內(nèi)可沿著任何壓力卷動并且連接到被預(yù)先安裝的機器控制器的界面控制。 操作材料混合 每年有超過7000噸的熱塑性材料被使用,大部分是PP，PS和PE，但是也有一個部分材料占有相當(dāng)高的比重，如PC，ABS，聚合物，尼龍，但不包括熱固性塑料和人工橡膠，所有的材料都要進(jìn)行抵達(dá)上的熔化流量分度和干燥檢查。該核心的材料操作系統(tǒng)在幾年前就安裝了，它由COKO設(shè)計和由來自MOTAN的AZO來提供一些主要的組件。物質(zhì)的混合和補澆測定是嚴(yán)格控制的，而且該系統(tǒng)合乎邏輯地布局在材料儲蓄區(qū)域和生產(chǎn)產(chǎn)品之間，已經(jīng)可以測定地認(rèn)為該系統(tǒng)已是影響 Coko的全部生產(chǎn)力的因素。 指著被堆積的來自GE塑料公司的一個充滿又可再度回收GECON容器，schromber 提到了如此表面上簡單的事物能如何成為生產(chǎn)力的因素。用草席墊著堅固且高容量的容器, 這樣就意謂著即使更快的運輸速度也仍然可以比較安心的進(jìn)出倉儲。當(dāng)空的時候,容器結(jié)構(gòu)在返回制造者時會在草席上自動崩潰，因此省去了許多以前花費在單程容器上的時間和金錢 客戶支持技術(shù) 步行在二長排的注射機之間，發(fā)現(xiàn)一臺機器看上去很結(jié)實模具形狀的，表面上泡沫上夾心嵌板，兩塊有顏色的零件，結(jié)構(gòu)上泡沫狀的實際是鍍金或描畫的，并且氣體輔助的結(jié)構(gòu)會忽略許多關(guān)于零件形狀的舊尺寸，流道長度和型腔壁厚，這對客戶會有阻礙嗎？完全不是，shromber 說，選擇模具和模具技術(shù)這不是客戶所要做的，即使它很有經(jīng)驗并一開始就有了非常清晰地關(guān)于產(chǎn)品的方案。 Coko客戶的第一步驟是讓他們看看零件裝配的規(guī)范，這最重要的是實際知識的運用，注射技術(shù)的選擇仰賴較多的事物超過零件的實際尺寸。零件如何動作呢? 決定性的運轉(zhuǎn)需求是什么? 它在市場中的競爭力怎樣? 該項目的質(zhì)量和費用參數(shù)如何？他們尋找一切可以為客戶創(chuàng)造利益的方案。 氣體- 輔助的優(yōu)勢 Coko六年前就開始使用氣體輔助技術(shù),在決定進(jìn)入這一領(lǐng)域時他們發(fā)現(xiàn)IKV在這方面很擅長，該塑料研究所和德國的一所大學(xué)RWTH有密切關(guān)系，這可是一個塑料人才庫，它有500多個很善長于該課題并都有很扎實的理論基礎(chǔ)，Schromber就是一所 Aachen 大學(xué)的畢業(yè)生,在大約同一個時間加入了Coko公司。和IKV 繼續(xù)密切合作如同他加入Coko工作一樣。 氣體輔助領(lǐng)域是一個需要專家親自操作獲得經(jīng)驗的工作，這一點非常重要，比如說IKV就攝制了一個特別的顯示發(fā)生在模腔內(nèi)部的氣體輔助過程的錄像。它首先要制造一個帶有透明窗口的模具，當(dāng)你看到這份錄像時，你就會得到一個很簡單的結(jié)論：氣體并不像你覺得很合乎邏輯地那樣，它經(jīng)常并不是對稱地通過零件，即使是一個對稱的零件，而且該錄像清楚地顯示COKO也參與了錄像的制作。 Schromber說，Coko現(xiàn)在幾乎是直接地往模腔里注射氣體而不需經(jīng)過噴嘴，如果氣體流程不對稱，而且你又是經(jīng)過噴嘴注入的話，澆口就很有可能偏心，模具也就被安裝在偏離定模板的中心,那你就不得不面對定模板并行所帶來的損失。Coko時常使用多種氣體注射口以便更精確地控制氣壓的分布，利用熱橫流道技術(shù)有嫻熟地放置的澆口。同時，氣體安排進(jìn)入那些口之內(nèi)是有順序的。然而,這有一個方法決定該哪里放置氣體口和澆口以及如何排序和給它們加壓。 原型制作和模擬 我們大部份同意在加工任何模具塊之前來制作原型和模具模擬是一個不錯的工序。 當(dāng)一個模具和COKO公司正常模具一樣大小以及有相應(yīng)大的資金時，COKO覺得它們沒有太多原型制作和模擬的資金。如果客戶不提供產(chǎn)品原型，COKO則會向附近幾家有STL設(shè)備的公司幫忙，模具原型則可在車間內(nèi)部加工出來，不過通常是鋁制的模具并且內(nèi)部是泡沫型的零件。 當(dāng)它得到模塑模擬的時候, Coko 再一次利用它和IKV學(xué)會密切關(guān)系的優(yōu)勢。IKV 已經(jīng)發(fā)展而且開放買賣它自己的鑄模設(shè)計軟件包,Cadmould-3D立體，含廣泛的鑄模模擬。當(dāng)他們需要完全地確定設(shè)計的時候，IKV和Coko提供的模擬可以和實際生產(chǎn)的一樣多。模擬的精彩部分是放置很多的氣體口和噴嘴。為了更好地使用 Cadmould，IKV 提供一套完整的數(shù)據(jù)線給Coko為機器處理叁數(shù):模具和材料的溫度，注射壓力，保持溫度，壓力和時間等等。 很多的時候當(dāng)Coko受益于充分的準(zhǔn)備時,它的客戶獲益更多。為日本的佳能公司制造復(fù)印機純平顯示器就證明了這一點，以前，零件是在日本已經(jīng)制好并涂上了泡沫劑，會有下沉的輪轂和其他的厚斷面的印記，而且總體的質(zhì)量水平達(dá)不到佳能公司所期望的，所以COKO用氣體輔助系統(tǒng)給它換了一個結(jié)實的零件，噴涂的費用也馬上節(jié)省了，平均厚度以及總體質(zhì)量也都減少了一半，這樣連同材料的費用也減少了，顯示器零件的生產(chǎn)周期也從以前用泡沫制造時的三分鐘減少到現(xiàn)在的不到90秒，而且那些質(zhì)量問題也變成了歷史。 這些 "超過簡單模塑" 計劃不是偶然出現(xiàn)的。為了安全起見，Coko已經(jīng)建造一個含嵌入和嵌出件，超聲波和振動焊接,屏幕和填補印刷，熱沖鍛加工件，和一個含 EMI 屏隔的完全涂刷設(shè)施的組合操作。不像在金屬處理的車間加工一樣了，能在附近控制臺被工人操作。Coko正與制造大而復(fù)雜零件的客戶提供了單點負(fù)責(zé)制，而且提供實際知識以便給客戶獲得更重要的利益。該項規(guī)則正在實行著。