R190柴油機(jī)機(jī)體機(jī)械加工工藝及其組合機(jī)床鉆孔夾具設(shè)計(jì)含開題及8張CAD圖,r190,柴油機(jī),機(jī)體,機(jī)械,加工,工藝,及其,組合,機(jī)床,鉆孔,夾具,設(shè)計(jì),開題,cad XXXXXX XX設(shè)計(jì)任務(wù)書 畢業(yè)生 姓名 專業(yè) 指導(dǎo)教師 姓名 類別 學(xué)號(hào) 班級(jí) 職稱 外聘、 √ 本校 一、畢業(yè)設(shè)計(jì)題目 R190柴油機(jī)機(jī)體機(jī)械加工工藝及其 組合機(jī)床鉆孔夾具設(shè)計(jì) 二、畢業(yè)設(shè)計(jì)提供的原始數(shù)據(jù)資料 箱體類是機(jī)器或部件的基礎(chǔ)零件，它將機(jī)器或部件的一些軸、套、軸承和齒輪等有關(guān)零件裝配起來，使其保持正確的相互位置關(guān)系，以傳遞轉(zhuǎn)矩或改變轉(zhuǎn)速來完成規(guī)定的運(yùn)動(dòng)。因此，箱體的加工質(zhì)量對(duì)機(jī)器的工作精度、使用性能和壽命都有直接的影響。 箱體零件雖然結(jié)構(gòu)多種多樣，但有共同的特點(diǎn)：多為鑄造件，結(jié)構(gòu)復(fù)雜，壁薄且不均勻，內(nèi)部呈腔形，加工部位多，加工難度大。既有精度要求較高的孔系和平面，也有許多精度要求較低的緊固件。箱體類零件上面的孔與孔之間有較高的位置精度（孔與孔的平行度、孔的軸線與面有垂直度要求），其加工質(zhì)量的好壞直接影響柴油機(jī)的精度和使用性能，因此柴油機(jī)汽缸的加工質(zhì)量至關(guān)重要。箱體類零件的機(jī)械加工勞動(dòng)量約占整個(gè)產(chǎn)品加工量的15%～20%。 R190型柴油機(jī)的用途：?主要用于農(nóng)用機(jī)械如手扶拖拉機(jī)等。 R190型柴油機(jī)的結(jié)構(gòu)特點(diǎn)：?機(jī)體：汽缸體和曲軸箱鑄成整體，兩側(cè)有檢查孔，汽缸套為濕式，用球墨鑄鐵制成，耐磨性好。曲軸：用球墨鑄鐵制成，經(jīng)正火處理后，提高了機(jī)械性能，耐磨性好。? 三、畢業(yè)設(shè)計(jì)應(yīng)完成主要內(nèi)容： 1、畢業(yè)設(shè)計(jì)說明書： 1.分析柴油機(jī)機(jī)體零件結(jié)構(gòu)特點(diǎn) 2.對(duì)機(jī)體零件進(jìn)行工藝分析 3.確定機(jī)械毛坯種類和余量及毛坯尺寸 4.定制機(jī)體加工的工藝過程 5.確定切削用量及基本工時(shí) 6.鉆孔的夾具設(shè)計(jì) 2、畢業(yè)設(shè)計(jì)圖紙： （1）總體設(shè)計(jì)完整、圖紙表達(dá)清晰； （2）機(jī)體毛坯圖； A1 1張 （3）機(jī)體零件圖； A0 1張 （4）機(jī)械加工工藝過程卡片； A4 3張 （5）機(jī)械加工工序卡片； A0 2張 （6）夾具裝配圖； A0 1張 （7）夾具零件圖； A1 1張 （8）夾具零件圖（手繪）； A1 2張 四、畢業(yè)生應(yīng)提交的畢業(yè)設(shè)計(jì)資料要求 1、畢業(yè)設(shè)計(jì)說明書： （1）畢業(yè)設(shè)計(jì)說明書必須打印成冊(cè)； （2）按山西工程技術(shù)學(xué)院畢業(yè)設(shè)計(jì)說明書撰寫規(guī)范 （3）說明書正文40000字 （4）說明書按要求內(nèi)容填寫完備 （5）同時(shí)提交電子文檔； （6）電子文檔的格式是： ①說明書必須是Word．DOC和EXCEL．Xls ②圖紙?zhí)峤坏碾娮游臋n資料必須是AUTOCAD．dwg的格式。 （7）郵箱地址（E-Mail）：liruibin-2002@163.com 2、畢業(yè)設(shè)計(jì)圖紙： （1）總體設(shè)計(jì)完整、圖紙表達(dá)清晰； （2）機(jī)體毛坯圖； A1 1張 （3）機(jī)體零件圖； A0 1張 （4）機(jī)械加工工藝過程卡片； A4 3張 （5）機(jī)械加工工序卡片； A0 2張 （6）夾具裝配圖； A0 1張 （7）夾具零件圖； A1 1張 （8）夾具零件圖（手繪）； A1 2張 五、設(shè)計(jì)進(jìn)度安排（從第5周起） 序號(hào) 時(shí)間 周次 設(shè)計(jì)任務(wù)完成的內(nèi)容及質(zhì)量要求 1 3.28-4.2 1 查閱和收集資料、調(diào)研 2 4.3-4.9 1 分析數(shù)據(jù)和相關(guān)資料 3 4.10-4.30 3 相關(guān)的設(shè)計(jì)計(jì)算、校核等 4 5.1-5.7 1 繪制裝配圖和零件圖 5 5.8-5.14 1 修改、完成裝配圖和零件圖 6 5.15-5.21 1 編寫設(shè)計(jì)計(jì)算說明書 7 5.22-5.28 1 修改、完成說明書 8 5.29-6.5 1 檢查說明書、圖紙并定稿打印 9 10 11 12 六、主要參考文獻(xiàn)資料 1、工具書： 1. 呂明，《機(jī)械制造技術(shù)基礎(chǔ)》 武漢理工大學(xué)出版社.2012 2. 鄧文英，宋力宏，《金屬工藝學(xué)》 高等出版社.2012 3. 濮良貴，《機(jī)械設(shè)計(jì)》 高等教育出版社.2012 2、參考資料： [1] 浦林祥.《金屬切削機(jī)床夾具設(shè)計(jì)手冊(cè)》 機(jī)械工業(yè)出版社.2009 [2] 李洪.《機(jī)械加工工藝手冊(cè)》 北京出版社.2010 [3] 薛源順.《機(jī)床夾具設(shè)計(jì)》 機(jī)械工業(yè)出版社.2010 [4] 吳宗澤.《機(jī)械零件設(shè)計(jì)手冊(cè)》 機(jī)械工業(yè)出版社.2010 七、簽字欄 簽 字 欄 畢業(yè)生 姓名 專業(yè) 班級(jí) 要求設(shè)計(jì)工作起止日期 教師審核 指導(dǎo)教師（簽字） 日期 201 年 月 日 教研室主任審查（簽字） 日期 201 年 月 日 系主任批準(zhǔn)（簽字） 日期 201 年 月 日 第3頁 共 3頁 太原理工大學(xué)陽泉學(xué)院-----畢業(yè)設(shè)計(jì)任務(wù)書 外文文獻(xiàn) Development of R190 diesel engine One. A foreword The development of diesel engine has more than 100 years of history， to human production and life has brought extraordinary convenience， also provides a extraordinary power to the development of human society. In more than a century of development， the diesel engine technology has appeared three qualitative leap. In the industrial developed countries， the truck basically all use diesel engine. In recent years， along with the diesel engine turbocharger， cold， direct injection， exhaust catalytic conversion and particle capture and other advanced technology， diesel engine emissions has reached Euro III and Euro IV emission standard， which set off a climax of car diesel engine， Volkswagen， general motors in the United States， Toyota Motor Company of a large car company car also uses the diesel engine. In China， the oil resource is becoming more and more scarce， the development of diesel vehicles will be the future focus of the automotive industry. Currently on the market of diesel passenger cars mainly MPV and SUV models， imported cars have the Touareg， Phaeton， Dodge Charger etc.， the independent brand are the Great Wall hover， Kairui. Diesel engine compression ratio， high thermal efficiency， fuel consumption than the gasoline engine lower by 30% to 40%， with the car with diesel and gasoline compared and low processing cost 5%， with the common attention of automotive energy all over the world， automobile engine to diesel engine development is the trend of the global automobile industry development. In addition to the fuel consumption than the gasoline engine is low， the diesel engine and gasoline engine compared to 1. The thermal efficiency is high; 2 units power low weight;. Widely used in exhaust gas turbocharger and improve the degree of supercharging; 4. Diesel engine without ignition system， so fault is less easy maintenance and reliable work. But the speed is lower than the gasoline engine， the quality is big， the manufacture and the maintenance cost is high， the noise is big， starts the difficulty and so on. But the disadvantages of the diesel engine is overcome， with the improvement of the diesel engine speed index， quality index， noise index， smaller harmful gas pen gasoline engine coupled with diesel engine sent many (especially CO) and in small and medium-sized car is provided with the trend of the diesel engine more more obvious. Two. R190 diesel engine uses: ??? ?R190 diesel land with pulleys， couplings， clutches as agricultural irrigation and drainage， a generator， an electric welding machine， air compressor， water pump， crusher and construction machinery power; by boat， with reversing car clutch. The reduction gear box， can be used as a fiing ship power， inland shipping and ship auxiliary host. Three.R190 type diesel engine structural characteristics: 1， a machine body， a cylinder body and a crankcase cast as a whole， inspection hole on both sides， cylinder liner is wet， made of ductile cast iron， wear resistance. 2， crankshaft: made of ductile cast iron， normalizing treatment， improve the mechanical properties， wear resistance. 3， cylinder cover: each cylinder cover， inlet and exhaust ports are placed on one side and the other side is provided with a fuel injection machine， cylinder head made of cast iron. 4， connecting rod with 45# steel die forging， the rod body for the font， the bulk of the flat cut. 5， piston made of aluminum alloy. Equipped with three gas rings and two oil rings， first ring porous chrome plated piston pin for high-quality steel carburizing， quenching. 6， air distribution mechanism， the intake and exhaust valve is made of heat resistant steel， cam shaft with graphite cast iron. 7， the lubricating system for the pressure splash compound， the pump for the grade gear pump. 8， the governor for the whole process of mechanical centrifugal. 9， with a single type of injection pump， injector for the single hole axis oblique type. Fourth.the current situation and development of diesel engines: ???? Early seventies， and for the first time by the introduction of emissions regulations affecting the world oil crisis， fuel-efficient diesel engines and low HC， CO emissions characteristics of renewed attention， the industry has begun a new generation of diesel engine research and development， aimed at increasing the power of the diesel engine and reduce exhaust emissions and noise and vibration. This provides new opportunities for application in diesel cars. Development of the simultaneous development of world science and technology， especially electronic technology， precision machining， new materials and other high-tech testing equipment for the realization of this technology may provide opportunities. 20 years later， the new diesel engine combustion， direct injection combustion system， turbocharged and intercooled， electronically controlled high pressure injection， EGR and four-valve structures and other new technologies have been developed to the extent practical， diesel exhaust after treatment technology and high quality diesel the development has also made substantial progress. ??????Modern automotive diesel engine has excellent overall performance high thermal efficiency， high power， high torque and low fuel consumption， low emission， low noise: or power increase of more than 15%， direct injection diesel engine fuel consumption by 20% to 30% compared with gasoline ， exhaust emissions meet Euro III ~ Euro IV standard， overall greenhouse gas emissions 45% lower than gasoline， noise and vibration basically reached the level of gasoline. Thus significantly speed up the process of commercial vehicle diesel fuel， diesel cars get widely used. China joined the WTO， the world's engine and parts production has shifted from the high-cost areas to low-cost areas. Therefore， at present in China we have established a number of foreign engine parts， comprising: electronic control system， oil pump and nozzle turbocharger， electrical appliances， pistons， piston rings， bearings， cylinder heads and body filters and other products . Use of foreign resources to make up for a lot less than the internal combustion engine parts industry technology and equipment， and promote the product upgrade key components， but also provides a car with better conditions to improve diesel technology level. Changes in outstanding technology development around the theme of environmental protection and accelerate the electronically controlled， high-pressure injection， application and development of direct injection， turbocharged and intercooled， and other advanced technology， the Chinese automotive diesel technology on a new level level. The current annual production capacity of single-cylinder diesel engine of more than 12 million units， while production and sales at 700 million units， the products are very competitive， has entered the era of low-profit or non-profit. Therefore， the industry must speed up structural adjustment， to further enhance the level of technology and optimize the product structure. The current focus is the development of single-cylinder machine technology to accelerate the development and adaptation of supporting host more energy， materials， and high reliability of the new generation of models. Existing products to improve reliability and reduce noise and smoke; the next step should be to promote direct injection， lightweight， multi-cylinder technology. However， these can only be achieved through the progressive economic development， but also the need to improve the performance of the host match， matching rationalization combined. Meanwhile， China's farm vehicles at the time to explore the international market will encounter emission standards. For this reason there are many manufacturers to tackle the problems， the general measures taken include increasing injection pressure and replaced with foreign high-quality small aperture injector， delayed injection timing， and some also reduce the average effective pressure， appropriate to reduce the gap with the cylinder and intake valve stem portion plus seals to reduce oil consumption， and so on. Comparison of these simple measures， increasing the cost less. According to reports， it has been tested on some models of the vortex chamber reached Euro I standard， but the key still in production consistency. The existing direct-injection models， these measures alone are difficult to reach Euro I standards. Multi-cylinder turbocharged diesel engine for small， the cost will increase by 50% the left and right， this may have some impact on the promotion of the use. In addition， since further reduce the gap with the cylinder， the cylinder body will involve complex large class of stiff problems， difficult to achieve in some older models. ????Compared with foreign and Chinese car behind generally 10 to 15 years with a diesel engine products， product variety also "lack of car less heavy"， key components of the fuel injection system， are still severely restricted the development of the whole product. Emission regulations in China is growing at about Europe later than 5 to 8 years the speed of advance， to change from Euro II to Euro III， Euro IV leap still faces many difficulties. A large gap between the level of foreign and largely due to lack of technical reserves. Because of funding， management mechanism and means of scientific research and other reasons， China diesel engine industry leading international diesel and master the key technology is not enough， self-development capability is not strong， but difficult to be innovative and breakthrough. Fifth.the technology development of the diesel engine ????The 21st century is the era of science and technology and the era of highly developed productive forces， but also full of challenges and opportunities. World auto industry continues to face global environmental pollution and scarcity of oil resources and other issues， the United States， Japan and European countries regard the "reduce vehicle pollution impact on the environment and energy conservation" as the 21st century cutting-edge issues of automotive technology， but also to solve the problem ways also been a consensus， that is， "three arrows shot" - the development of fuel cell powered future， clean fuel engine development， and improve the development of diesel engines， gasoline engines. For automotive diesel engine， the key direction is to further reduce fuel consumption， NOX emissions and particulate matter emissions in order to meet future more stringent emission regulations and fuel consumption regulations. Future technology development will be important to further optimize the combustion process， after the development of more effective and practical exhaust aftertreatment system and the introduction of new high-quality low-sulfur fuel. ????In the development of new models， the introduction of foreign advanced production joint venture models， this road or take the self-development，This is an issue of great concern to many companies. Despite the introduction of the road can go rapidly improve the technical quality of the diesel engine And management level， but higher diesel prices abroad， even if the use of cheap labor costs is difficult At present our people down to acceptable levels. Therefore， the relevant industry believes that， for agricultural diesel engine， should Mainly to independent development， the development of existing products on the basis of a more proper way. ??Which， it is worth noting that the main object is to use agricultural diesel engine are farmers， of rural productivity is still not high， low economic strength， individual purchase farm-based market， even in the 21st century， it is impossible to reach the current the level of industrialized countries in rural areas. In China， agricultural diesel industrial manufacturing technology can not be It can generally reach the level of developed countries in the short term. Therefore， our agricultural enterprises should identify the gap to catch up， But also down to earth from reality， the implementation of technology policy of seeking truth from facts， to promote agricultural technology into dieselstep. China should research projects have been carried out on the basis of direct injection， four-valve， turbocharged and intercooled， more in-depth study of electronically controlled high pressure injection and EGR， etc.， as soon as possible to grasp the extent practical. At the same time expand the research and development of diesel exhaust after-treatment system. Oil industry should cooperate to develop low-sulfur diesel. In terms of development approach， product development and technology development combined with industry， academia， research integration， self-development and international cooperation， the introduction of the combination.  中文譯文 R190柴油機(jī)的發(fā)展 一、前言 柴油機(jī)的發(fā)展已經(jīng)有一百多年的歷史，給人類的生產(chǎn)、生活帶來了非凡的便利，也給人類社會(huì)的發(fā)展提供了不同凡響的動(dòng)力。在一個(gè)多世紀(jì)的發(fā)展過程中，柴油機(jī)技術(shù)先后出現(xiàn)了三次質(zhì)的飛躍。 在工業(yè)發(fā)達(dá)國家，載貨汽車基本上全部使用柴油機(jī)。近年來，隨著柴油機(jī)采用渦輪增壓、中冷、直噴、尾氣催化轉(zhuǎn)換和顆粒捕集器等先進(jìn)技術(shù)，柴油機(jī)排放已達(dá)到歐Ⅲ、歐Ⅳ排放標(biāo)準(zhǔn)，因而也掀起了小轎車柴油機(jī)化的高潮，德國大眾汽車公司、美國通用汽車公司、日本豐田汽車公司等大型汽車公司的小轎車也采用了柴油機(jī)。在石油資源越來越短缺的我國，發(fā)展柴油車將是未來汽車工業(yè)的重點(diǎn)之一。目前市場(chǎng)上的柴油乘用車主要以MPV和SUV車型為主，進(jìn)口車方面有途銳、輝騰、道奇酷威等，自主品牌則主要有長城哈弗、開瑞等。 柴油機(jī)的壓縮比高，熱效率高，其燃料消耗量比汽油機(jī)低30%~40%，加上車用柴油與車用汽油相比加工成本又低5%，隨著世界各國對(duì)汽車節(jié)能的普遍重視，汽車發(fā)動(dòng)機(jī)向柴油機(jī)化發(fā)展已是全球汽車工業(yè)發(fā)展的大趨勢(shì)。 除燃料消耗量比汽油機(jī)低外，柴油機(jī)與汽油機(jī)相比1.熱效率高；2.單位功率的重量低；3.廣泛采用廢氣渦輪增壓并提高增壓度；4.柴油機(jī)沒有點(diǎn)火系統(tǒng)，因此故障較少容易保養(yǎng)，工作可靠。但是轉(zhuǎn)速較汽油機(jī)低，質(zhì)量大，制造和維修費(fèi)用高，噪音大，啟動(dòng)困難等。但柴油機(jī)的缺點(diǎn)正在得到克服，隨著柴油機(jī)的轉(zhuǎn)速指標(biāo)、質(zhì)量指標(biāo)、噪聲指標(biāo)等方面的改進(jìn)，加之柴油機(jī)派出的有害氣體筆汽油機(jī)少得多（尤其是CO），因而在中小型汽車上裝用柴油機(jī)的趨勢(shì)越來越明顯。 二、R190型柴油機(jī)的用途：? R190柴油機(jī)陸用時(shí)，配以皮帶輪、聯(lián)軸器、離合器作為農(nóng)業(yè)排灌、發(fā)電機(jī)、電焊機(jī)、空壓機(jī)、水泵、碎石機(jī)及建筑機(jī)械等動(dòng)力；船用時(shí)，配上倒順車離合器。減速齒輪箱后，可用作漁輪船動(dòng)力，內(nèi)河航運(yùn)主機(jī)及輪船輔機(jī)。 三、R190型柴油機(jī)的結(jié)構(gòu)特點(diǎn)：? 1、機(jī)體：汽缸體和曲軸箱鑄成整體，兩側(cè)有檢查孔，汽缸套為濕式，用球墨鑄鐵制成，耐磨性好。? 2、汽缸蓋：每缸一蓋，進(jìn)排氣道都安置在一側(cè)，另一側(cè)裝有噴油機(jī)，缸蓋用鑄鐵制成。 3、曲軸：用球墨鑄鐵制成，經(jīng)正火處理后，提高了機(jī)械性能，耐磨性好。? 4、活塞用鋁合金制成。裝有三道氣環(huán)和二道油環(huán)，第一環(huán)為多孔鍍鉻，活塞銷為優(yōu)質(zhì)鋼滲碳，表面淬火。 5、連桿用45#鋼模鍛而成，桿身為工字型，大頭為平切口。?? 6、潤滑系統(tǒng)為壓力飛濺復(fù)合式，油泵為等級(jí)齒輪泵。 7、配氣機(jī)構(gòu)，進(jìn)排氣門為耐熱鋼制成，凸輪軸用球墨鑄鐵。 四、柴油機(jī)的現(xiàn)狀與發(fā)展：? 七十年代初，受世界石油危機(jī)和首次出臺(tái)廢氣排放法規(guī)的影響，柴油機(jī)省油和低HC、CO排放的特點(diǎn)再度受到關(guān)注，工業(yè)界開始了新一代柴油機(jī)的研究開發(fā)，旨在提高柴油機(jī)動(dòng)力性并減少廢氣排放和噪聲振動(dòng)。這為柴油機(jī)在轎車上的應(yīng)用提供了新的機(jī)遇。世界科學(xué)技術(shù)的同步發(fā)展，尤其是電子技術(shù)、精密加工、新材料和測(cè)試裝備等高新技術(shù)的發(fā)展為實(shí)現(xiàn)這個(gè)機(jī)遇提供了技術(shù)可能。其后20多年，柴油機(jī)新燃燒方式、直噴燃燒系統(tǒng)、增壓中冷、電子控制高壓噴射、EGR和四氣門結(jié)構(gòu)等新技術(shù)均已發(fā)展到實(shí)用程度，對(duì)柴油機(jī)排氣后處理技術(shù)和優(yōu)質(zhì)柴油的開發(fā)也取得實(shí)質(zhì)性進(jìn)展。? 現(xiàn)代車用柴油機(jī)已具有高熱效率、高功率、高扭矩和低油耗、低排放、低噪聲等優(yōu)良的綜合性能：升功率增長超過15%，直噴式柴油機(jī)燃油耗比汽油機(jī)低20%~30%，廢氣排放達(dá)到歐III~歐IV標(biāo)準(zhǔn)，溫室效應(yīng)氣體排放總體上比汽油機(jī)低45%，噪聲振動(dòng)也基本上達(dá)到汽油機(jī)的水平。因而商用車柴油化進(jìn)程明顯加快，柴油轎車獲得推廣使用。 中國加入WTO，世界發(fā)動(dòng)機(jī)及其零部件生產(chǎn)也由高成本地區(qū)向低成本地區(qū)轉(zhuǎn)移。因此，目前在中國已建立了一批內(nèi)燃機(jī)零部件外資企業(yè)，包括：電控系統(tǒng)、油泵油嘴、增壓器、電機(jī)電器、活塞、活塞環(huán)、軸瓦、機(jī)體缸蓋鑄件和濾清器等產(chǎn)品領(lǐng)域。對(duì)國外資源的利用彌補(bǔ)了內(nèi)燃機(jī)零部件行業(yè)技術(shù)和裝備的諸多不足，促進(jìn)了關(guān)鍵零部件的產(chǎn)品升級(jí)，也為車用柴油機(jī)技術(shù)水平的提高提供了更好的條件。在技術(shù)發(fā)展方面的突出變化是圍繞環(huán)境保護(hù)的主旋律而加快了電子控制、高壓噴射、直噴燃燒室、增壓中冷等先進(jìn)技術(shù)的應(yīng)用和開發(fā)，使中國車用柴油機(jī)的技術(shù)水平上了新的臺(tái)階。? 當(dāng)前我國單缸柴油機(jī)的年生產(chǎn)能力超過1200萬臺(tái)， 而產(chǎn)銷量在700萬臺(tái)左右，產(chǎn)品競爭異常激烈，已進(jìn)入微利或無利時(shí)代。因此，行業(yè)結(jié)構(gòu)調(diào)整必須加快，以進(jìn)一步提高技術(shù)水平和優(yōu)化產(chǎn)品結(jié)構(gòu)。當(dāng)前單缸機(jī)技術(shù)發(fā)展的重點(diǎn)是加快開發(fā)與配套主機(jī)更加適應(yīng)的節(jié)能、節(jié)材和高可靠性的新一代機(jī)型?，F(xiàn)有產(chǎn)品要提高可靠性、降低噪聲和煙度；下一步應(yīng)推廣直噴化、輕量化、多缸化。但這些只能通過經(jīng)濟(jì)發(fā)展逐步實(shí)現(xiàn)，還必須與主機(jī)的匹配性能提高，匹配合理化相結(jié)合。同時(shí)，我國農(nóng)用運(yùn)輸車在探討進(jìn)入國際市場(chǎng)時(shí)也會(huì)遇到排放標(biāo)準(zhǔn)問題。已有不少廠家為此進(jìn)行攻關(guān)，一般采取的措施包括提高噴油壓力，換用國外高質(zhì)量小孔徑噴油器，推遲噴油定時(shí)，有的還降低平均有效壓力，適當(dāng)減少配缸間隙和進(jìn)氣閥桿部加密封圈以降低機(jī)油耗等等。這些措施比較簡單易行，成本增加也較少。據(jù)報(bào)道，已在某些渦流室機(jī)型上試驗(yàn)達(dá)到了歐I標(biāo)準(zhǔn)， 但關(guān)鍵還在生產(chǎn)的一致性。在現(xiàn)有的直噴機(jī)型上，只靠這些措施是難以達(dá)到歐I標(biāo)準(zhǔn)的。采用渦輪增壓對(duì)于小型多缸柴油機(jī)來說，成本將會(huì)增加50%左 右，這對(duì)推廣使用可能會(huì)有一定影響。此外，由于進(jìn)一步減少配缸間隙，將涉及機(jī)體缸頭等復(fù)雜大件的剛性問題，在一些較老的機(jī)型上實(shí)現(xiàn)較難。 而且中國車用柴油機(jī)產(chǎn)品水平與國外相比總體上落后10~15年，產(chǎn)品品種還“缺轎少重”，燃油噴射系統(tǒng)等關(guān)鍵零部件仍嚴(yán)重制約整機(jī)產(chǎn)品的發(fā)展。排放法規(guī)方面中國正以大約遲于歐洲5~8年的速度推進(jìn)，要實(shí)現(xiàn)從歐II到歐III、歐IV的跨越還面臨不少困難。與國外水平差距較大的主要原因在于技術(shù)儲(chǔ)備不足。由于經(jīng)費(fèi)投入、管理機(jī)制和科研手段等多種原因，中國柴油機(jī)界對(duì)國際柴油機(jī)的領(lǐng)先和關(guān)鍵技術(shù)掌握不夠、自主開發(fā)能力不強(qiáng)、更難以有所創(chuàng)新和突破。 五、柴油機(jī)的技術(shù)發(fā)展方向? 21世紀(jì)是科學(xué)技術(shù)和生產(chǎn)力高度發(fā)展的時(shí)代，也是充滿挑戰(zhàn)和機(jī)遇的時(shí)代。世界汽車工業(yè)繼續(xù)面臨全球環(huán)境污染和石油資源匱乏等問題，美國、日本和歐洲各國都把“降低汽車污染對(duì)環(huán)境的沖擊和節(jié)約能源”列為21世紀(jì)汽車技術(shù)的前沿問題，而且對(duì)解決問題的途徑也有所共識(shí)、也就是“三箭齊發(fā)”－燃料電池等未來動(dòng)力的開發(fā)，清潔燃料發(fā)動(dòng)機(jī)的開發(fā)，以及柴油機(jī)、汽油機(jī)的改進(jìn)開發(fā)。對(duì)車用柴油機(jī)而言，重點(diǎn)方向是進(jìn)一步降低油耗、NOX排放和顆粒物排放，以滿足未來更嚴(yán)格的燃油耗法規(guī)和排放法規(guī)。今后技術(shù)開發(fā)將重于進(jìn)一步優(yōu)化燃燒過程、開發(fā)更為有效和實(shí)用的排氣后處理系統(tǒng)以及采用新的低硫優(yōu)質(zhì)燃料。 在開發(fā)新機(jī)型時(shí)，是引進(jìn)國外先進(jìn)機(jī)型合資合作生產(chǎn)，還是走自主開發(fā)這路，這是眾多企業(yè)非常關(guān)心的問題。盡管走引進(jìn)之路可迅速提高我國柴油機(jī)的技術(shù)質(zhì)量水平和管理水平，但是國外柴油機(jī)價(jià)格較高，即使利用我國廉價(jià)勞動(dòng)力價(jià)格也難以降到目前我國人民能接受的水平。因此有關(guān)業(yè)內(nèi)人士認(rèn)為，對(duì)于農(nóng)用柴油機(jī)，仍應(yīng)以自主開發(fā)為主，在現(xiàn)有產(chǎn)品基礎(chǔ)上發(fā)展，是較為正確的路子。 其中，值得注意的是，農(nóng)用柴油機(jī)的主要使用對(duì)象是農(nóng)民，我國農(nóng)村目前仍然是生產(chǎn)效率不高、經(jīng)濟(jì)實(shí)力低、農(nóng)機(jī)以個(gè)人購買為主的市場(chǎng)，即使到了21世紀(jì)中葉，也不可能達(dá)到目前工業(yè)發(fā)達(dá)國家農(nóng)村的水平。而我國農(nóng)用柴油機(jī)工業(yè)制造技術(shù)水平也不可能在短期內(nèi)普遍達(dá)到發(fā)達(dá)國家的水平。因此我國農(nóng)機(jī)企業(yè)既要找準(zhǔn)差距奮起直追，又要腳踏實(shí)地地從實(shí)際出發(fā)，實(shí)行實(shí)事求是的技術(shù)政策，促進(jìn)農(nóng)田柴油機(jī)的技術(shù)進(jìn)步。 中國應(yīng)在目前已經(jīng)開展的研究項(xiàng)目基礎(chǔ)上，對(duì)直噴燃燒室、四氣門、增壓中冷、電控高壓噴射和EGR等進(jìn)行更深入的研究，早日掌握到實(shí)用程度。同時(shí)展開柴油機(jī)排氣后處理系統(tǒng)的研究開發(fā)。應(yīng)配合石油業(yè)界進(jìn)行低硫柴油的開發(fā)。在開發(fā)途徑方面，產(chǎn)品開發(fā)與技術(shù)開發(fā)相結(jié)合，產(chǎn)、學(xué)、研相結(jié)合，自行開發(fā)與國際合作、引進(jìn)相結(jié)合。