臥式雙面28軸組合鉆床左主軸箱設(shè)計,臥式雙面28軸組合鉆床左主軸箱設(shè)計,臥式,雙面,28,組合,鉆床,主軸,設(shè)計 黃河科技學(xué)院畢業(yè)設(shè)計（文獻(xiàn)翻譯） 第 9 頁 NC Technology Shigley J E. Mechanical Engineering Design. New York: McGraw-Hill, 1998 Abstract: A machine is a combination of mechanisms and other components which transforms, transmits. Examples are engines, turbines, vehicles, hoists, printing presses, washing machines, and movie cameras. Many of the principles and methods of design that apply to machines also apply to manufactured articles that are not true machines. The term "mechanical design" is used in a broader sense than "machine design" to include their design. the motion and structural aspects and the provisions for retention and enclosure are considerations in mechanical design. Applications occur in the field of mechanical engineering, and in other engineering fields as well, all of which require mechanical devices, such as switches, cams, valves, vessels, and mixers. Keywords: NC Technology 1、Research current situation of NC lathe in our times Research and development process to such various kinds of new technologies as numerical control lathe , machining center , FMS , CIMS ,etc. of countries all over the world, linked to with the international economic situation closely. The machine tool industry has international economy to mutually promote and develop, enter 21 alert eras of World Affairs, the function that people's knowledge plays is more outstanding , and the machine tool industry is regarded as the foundation of the manufacturing industry of the machine, its key position and strategic meaning are more obvious. Within 1991-1994 years, the economic recession of the world, expensive FMS, CIMS lowers the temperature, among 1995-2000 years, the international economy increases at a low speed, according to requisition for NC lathe and the world four major international lathes exhibition in order to boost productivity of users of various fields of present world market (EMO , IMTS , JIMTOF , China CIMT of Japan of U.S.A. of Europe), have the analysis of the exhibit, there are the following several points mainly in the technical research of NC lathe in our times: （1）、Pay more attention to new technology and innovation Worldwide , are launching the new craft , new material , new structure , new unit , research and development of the new component in a more cost-effective manner, developmental research of for instance new cutter material , the new electric main shaft of main shaft structure , high speed , high-speed straight line electrical machinery ,etc.. Regard innovating in improvement of the processing technology as the foundation, for process ultra and hard difficult to cut material and special composite and complicated part , irregular curved surface ,etc. research and develop new lathe variety constantly. （2）、Improve the precision and research of machine tooling In order to improve the machining accuracy of the machining center , are improving rigidity of the lathe , reduction vibration constantly, dispel hotly and out of shape, reduce the noise , improve the precision of localization of NC lathe , repeat precision , working dependability , stability , precision keeping, world a lot of country carry on lathe hot error , lathe sport and load out of shape software of error compensate technical research, take precision compensate , software compensate measure improve , some may make this kind of error dispel 60% already. And is developing retrofit constantly, nanometer is being processed. （3）、Improve the research of the machine tooling productivity World NC lathe, machining center and corresponding some development of main shaft , electrical machinery of straight line , measuring system , NC system of high speed, under the prerequisite of boosting productivity. （4）、What a lot of countries have already begun to the numerical control system melt intelligently, openly, study networkedly elligent research of the numerical control system Mainly showing in the following aspects: It is intelligent in order to pursue the efficiency of processing and process quality, the self-adaptation to the processing course is controlled, the craft parameter produces research automatically; Join the convenient one in order to improve the performance of urging and use intelligently, to the feedback control , adaptive operation , discerning automatically load selects models automatically , since carries on research whole definitely ,etc. of the electrical machinery parameter; There are such research of the respect as intelligent automatic programming , intelligent man-machine interface , intelligence diagnosing , intelligent monitoring ,etc.. The numerical control system melts and studies open Mainly showing in the following aspects: The development of the numerical control system is on unified operation platform, face the lathe producer and support finally, through changing, increasing or cutting out the structure target(numerical control target ), form the seriation, and can use users specially conveniently and the technical know-how is integrated in the control system, realize the open numerical control system of different variety , different grade fast, form leading brand products with distinct distinction. System structure norm of the open numerical control system at present, norm , disposing the norm , operation platform , numerical control systematic function storehouse and numerical control systematic function software developing instrument ,etc. are the core of present research to pass through. Meeting the manufacture system of the production line , demand for the information integration of the manufacturing company networkedly greatly of numerical control equipment, it is a basic unit of realizing the new manufacture mode too. 2、Classification of the machining center （1）Process according to main shaft space position when it classifies to be as follows, horizontal and vertical machining center. Horizontal machining center, refer to the machining center that the axis level of the main shaft is set up . Horizontal machining center for 3-5 sport coordinate axis, a common one three rectilinear motion coordinate axis and one turn the coordinate axis of sports round (turn the workingbench round), it can one is it is it finish other 4 Taxi processing besides installing surfaces and top surfaces to insert to install in work piece, most suitable for processing the case body work piece . Compared with strength type machining center it, the structure is complicated, the floor space is large, quality is large, the price is high. Vertical machining center, the axis of the main shaft of the vertical machining center, in order to set up vertically, its structure is mostly the regular post type, the workingbench is suitable for processing parts for the slippery one of cross, have 3 rectilinear motion coordinate axis generally , can find a room for one horizontal numerical control revolving stage (the 4th axle ) of axle process the spiral part at workingbench. The vertical machining center is of simple structure, the floor space is small, the price is low, after allocating various kinds of enclosures , can carry on the processing of most work pieces . Large-scale gantry machining center, the main shafts are mostly set up vertically, is especially used in the large-scale or with complicated form work piece , is it spend the many coordinate gantry machining center to need like aviation , aerospace industry , some processing of part of large-scale steam turbine. Five machining centers, this kind of machining center has function of the vertical and horizontal machining center, one is it after inserting , can finish all five Taxi processing besides installing the surface to install in work piece, the processing way can make form of work piece error lowest , save 2 times install and insert working, thus improve production efficiency , reduce the process cost. (2)Classify by craft use Is it mill machining center to bore, is it mill for vertical door frame machining center , horizontal door frame mill the machining center and Longmen door frame mill the machining center to divide into. Processing technology its rely mainly on the fact that the door frame is milled, used in case body, shell and various kinds of complicated part special curve and large processes , curved surface of outline process, suitable for many varieties to produce in batches small. Complex machining center, point five times and compound and process mainly, the main shaft head can be turned round automatically, stand, lie and process, after the main shaft is turned round automatically, realize knowing that varies in the horizontal and vertical direction. (3)Classify by special function Single workingbench , a pair of workingbench machining center; Single axle , dual axle , three axle can change machining center , main shaft of case; Transfer vertically to the tower machining center and transfer ; One hundred sheets of storehouses adds the main shaft and changes one one hundred sheets of machining centers; One hundred sheets of storehouses connects and writes hands to add the main shaft and change one hundred sheets of machining centers; One hundred sheets of storehouses adds the manipulator and adds one pair of main shafts to transfer to the tower machining center. 3、Development trend of the current numerical control lathe At present, the advanced manufacturing technology in the world is rising constantly, such application of technology as ultrafast cutting , ultraprecision processing ,etc., the rapid development of the flexible manufacturing system and integrated system of the computer one is constant and ripe, have put forward higher demand to the process technology of numerical control. Nowadays the numerical control lathe is being developed in several following directions. （1）. The speed and precision at a high speed , high accuracy are two important indexes of the numerical control lathe , it concerns directly that processes efficiency and product quality. At present, numerical control system adopt-figure number, frequency high processor, in order to raise basic operation speed of system. Meanwhile , adopt the super large-scale integrated circuit and many microprocessors structure, in order to improve systematic data processing ability , namely improve and insert the speed and precision of mending operation. Adopt the straight line motor and urge the straight line of the lathe workingbench to be servo to enter to the way directly, it is quite superior that its responds the characteristic at a high speed and dynamically. Adopt feedforward control technology , make it lag behind error reduce greatly , thus improve the machining accuracy cut in corner not to track. For meet ultrafast demand that process, numerical control lathe adopt main shaft motor and lathe structure form that main shaft unite two into one, realize frequency conversion motor and lathe main shaft integrate , bearing , main shaft of electrical machinery adopt magnetism float the bearing , liquid sound pigeonhole such forms as the bearing or the ceramic rolling bearing ,etc.. At present, ceramic cutter and diamond coating cutter have already begun to get application. （2）. Multi-functional to is it change all kinds of machining centers of organization (a of capacity of storehouse can up to 100 of the above ) automatically to furnished with, can realize milling paring , boring and pares , bores such many kinds of processes as paring , turning , reaming , reaming , attacking whorl ,etc. to process at the same time on the same lathe , modern numerical control lathe adopt many main shaft , polyhedron cut also , carry on different cutting of way process to one different position of part at the same time. The numerical control system has because adopted many CPU structure and cuts off the control method in grades, can work out part processing and procedure at the same time on a lathe , realize so-called " the front desk processes , the backstage supporter is an editor ". In order to meet the needs of integrating the systematic one in flexible manufacturing system and computer, numerical control system have remote serial interface , can network , realize data communication , numerical control of lathe, can control many numerical control lathes directly too. （3）. Intelligent modern numerical control lathe introduce the adaptive control technology, according to cutting the change of the condition, automatic working parameter, make the processing course can keep the best working state , thus get the higher machining accuracy and roughness of smaller surface , can improve the service life of the cutter and production efficiency of the equipment at the same time . Diagnose by oneself , repair the function by oneself, among the whole working state, the system is diagnosed, checked by oneself to CNC system and various kinds of equipment linking to each other with it at any time. While breaking down , adopt the measure of shutting down etc. immediately , carry on the fault alarm, brief on position , reason to break down ,etc.. Can also make trouble module person who take off automatically , put through reserve module , so as to ensure nobody demand of working environment. For realize high trouble diagnose that requires , its development trend adopts the artificial intelligence expert to diagnose the system. （4）. Numerical control programming automation with the development of application technology of the computer, CAD/CAM figure interactive automatic programming has already get more application at present, it is a new trend of the technical development of numerical control. It utilize part that CAD draw process pattern , is it calculate the trailing punishing to go on by cutter orbit data of computer and then, thus produce NC part and process the procedure automatically, in order to realize the integration of CAD and CAM. With the development of CIMS technology , the full-automatic programming way in which CAD/CAPP/CAM integrates has appeared again at present, it, and CAD/CAM systematic programming great difference their programming necessary processing technology parameter needn't by artificial to participate in most, get from CAPP database in system directly. （5）. The dependability of the dependability maximization numerical control lathe has been the major indicator that users cared about most all the time . The numerical control system will adopt the circuit chip of higher integrated level , will utilize the extensive or super large-scale special-purpose and composite integrated circuit, in order to reduce the quantity of the components and parts , to improve dependability . Through the function software of the hardware, in order to meet various kinds of demands for controlling the function, adopt the module , standardization , universalization and seriation of the structure lathe noumenonn of the hardware at the same time , make not only improve the production lot of the hardware but also easy to is it produce to organize and quality check on.. Still through operating and starting many kinds of diagnostic programs of diagnosing , diagnosing , diagnosing off-line online etc. automatically, realize that diagnoses and reports to the police the trouble to hardware , software and various kinds of outside equipment in the system. Utilize the warning suggestion, fix a breakdown in time; Utilize fault-tolerant technology, adopt and design the important part " redundantly ", in order to realize the trouble resumes by oneself; Utilize various kinds of test , control technology , exceed Cheng , one one hundred sheets of damages , interfering , cutting out ,etc. at the time of various kinds of accidents as production, carry on corresponding protection automatically. （6）. Control system miniaturization systematic miniaturization of numerical control benefit and combine the machine , electric device for an organic whole. Adopt the super large-scale integrated component , multi-layer printed circuit board mainly at present, adopt the three-dimensional installation method , make the electronic devices and components must use the high density to install, narrow systematic occupying the space on a larger scale. And utilize the new-type slim display of colored liquid crystal to substitute the traditional cathode ray tube, will make the operating system of numerical control miniaturize further. So can install it on the machine tool conveniently, benefit the operation of the numerical control lathe correctly even more. 數(shù)控技術(shù) 小倏逝波機(jī)械工程設(shè)計。 紐約:作家出版社,1998 摘要： 機(jī)器是由機(jī)械裝置和其它組件組成的。它是一種用來轉(zhuǎn)換或傳遞能量的裝置，例如：發(fā)動機(jī)、渦輪機(jī)、車輛、起重機(jī)、印刷機(jī)、洗衣機(jī)、照相機(jī)和攝影機(jī)等。許多原則和設(shè)計方法不但適用于機(jī)器的設(shè)計，也適用于非機(jī)器的設(shè)計。術(shù)語中的“機(jī)械裝置設(shè)計” 的含義要比“機(jī)械設(shè)計”的含義更為廣泛一些，機(jī)械裝置設(shè)計包括機(jī)械設(shè)計。在分析運動及設(shè)計結(jié)構(gòu)時，要把產(chǎn)品外型以及以后的保養(yǎng)也要考慮在機(jī)械設(shè)計中。在機(jī)械工程領(lǐng)域中，以及其它工程領(lǐng)域中，所有這些都需要機(jī)械設(shè)備，比如：開關(guān)、凸輪、閥門、船舶以及攪拌機(jī)等。 關(guān)鍵詞：數(shù)控技術(shù) 1、當(dāng)前世界NC機(jī)床的研究現(xiàn)狀 在世界各國里對數(shù)控機(jī)床、加工中心以至FMS、CIMS等各種新技術(shù)的研究與發(fā)展進(jìn)程，那是與世界經(jīng)濟(jì)形勢緊密相連的。機(jī)床工業(yè)有世界經(jīng)濟(jì)相互促進(jìn)和發(fā)展，進(jìn)入21世界知識機(jī)警時代，人們的知識所起的作用更加突出，而機(jī)床工業(yè)作為機(jī)器制造業(yè)的基礎(chǔ)，其重點地位與戰(zhàn)略意義也更加明顯。在1991—1994年間，衰退的世界經(jīng)濟(jì)，昂貴的FMS，CIMS降溫，1995—2000年間，世界經(jīng)濟(jì)在低速增長，根據(jù)當(dāng)前世界市場各方面用戶為提高生產(chǎn)率對NC機(jī)床的要求以及世界四大國際機(jī)床展（歐洲的EMO、美國的IMTS、日本的JIMTOF、中國的CIMT）上展品的分析，當(dāng)前世界NC機(jī)床的技術(shù)研究主要有以下幾點： （1）、更加重視新技術(shù)和創(chuàng)新 在世界各國范圍內(nèi)，對新工藝、新材料、新結(jié)構(gòu)、新單元、新元件的研究開發(fā)工作正在大力開展，如新的刀具材料、新的主軸結(jié)構(gòu)、高速電主軸、高速直線電機(jī)等的開發(fā)研究。以加工工藝的改進(jìn)創(chuàng)新為基礎(chǔ)，為加工超硬、難切削材料及特殊復(fù)合材料及復(fù)雜零件、不規(guī)則曲面等在不斷研究開發(fā)新機(jī)種。 （2）、提高機(jī)床加工的精度和精密研究 為了提高加工中心的加工精度，不斷提高機(jī)床的剛度、減少振動，消除熱變形，降低噪聲，提高NC機(jī)床的定位精度、重復(fù)精度、工作可靠性、穩(wěn)定性、精度保持性，世界很多國家都在進(jìn)行機(jī)床熱誤差、機(jī)床運動及負(fù)載變形誤差的軟件補償技術(shù)研究，并采取精度補償、軟件補償?shù)却胧┘右愿纳?，有的已?jīng)可以使此類誤差消除60%。并在不斷開發(fā)精細(xì)加工，納米加工。 （3）、提高機(jī)床加工生產(chǎn)率的研究 世界NC機(jī)床、加工中心及相應(yīng)的高速點主軸、直線電機(jī)、測量系統(tǒng)、NC系統(tǒng)的開發(fā)，均以提高生產(chǎn)率為前提。 （4）、許多國家都已經(jīng)開始對數(shù)控系統(tǒng)的智能化、開放化、網(wǎng)絡(luò)化研究 數(shù)控系統(tǒng)的智能化的研究 主要表現(xiàn)在：為滿足加工效率和加工質(zhì)量的智能化，對加工過程的自適應(yīng)控制，工藝參數(shù)自動生成進(jìn)行研究；為提高驅(qū)動性能及使用連接方便的智能化，對反饋控制、電機(jī)參數(shù)的自適應(yīng)運算、自動識別負(fù)載自動選定模型、自整定等進(jìn)行研究；還有智能化的自動編程、智能化的人機(jī)界面、智能診斷、智能監(jiān)控等方面的研究。 數(shù)控系統(tǒng)開放化研究 主要表現(xiàn)在：數(shù)控系統(tǒng)的開發(fā)在統(tǒng)一的運行平臺上，面對機(jī)床廠家和最終擁護(hù)，通過不斷改變、增加或剪裁結(jié)構(gòu)對象（數(shù)控對象），形成系列化，并可方便地將用戶的特殊應(yīng)用和技術(shù)訣竅集成到控制系統(tǒng)中，快速實現(xiàn)不同品種、不同檔次的開放式數(shù)控系統(tǒng)，形成具有鮮明個性的名牌產(chǎn)品。目前開放式數(shù)控系統(tǒng)的體系結(jié)構(gòu)規(guī)范、通行規(guī)范、配置規(guī)范、運行平臺、數(shù)控系統(tǒng)功能庫以及數(shù)控系統(tǒng)功能軟件開發(fā)工具等是當(dāng)前研究的核心。 數(shù)控裝備的網(wǎng)絡(luò)化將極大地滿足生產(chǎn)線制造系統(tǒng)、制造企業(yè)對信息集成的需求，也是實現(xiàn)新的制造模式的基礎(chǔ)單元。 2、加工中心的分類 （1）按主軸加工時的空間位置分類有：臥式和立式加工中心。 臥式加工中心，是以主軸軸線水平設(shè)置的加工中心。臥式加工中心一般具有3—5個運動坐標(biāo)軸，常見的是三個直線運動坐標(biāo)軸和一個回轉(zhuǎn)運動坐標(biāo)軸（回轉(zhuǎn)工作臺），它能在工件一次裝夾完成除安裝面和頂面以外的其余4個面的加工，最適合加工箱體類工件。它與力式加工中心相比，結(jié)構(gòu)復(fù)雜，占地面積大，質(zhì)量大，價格高。 立式加工中心，立式加工中心主軸的軸線為垂直設(shè)置，其結(jié)構(gòu)多為固定立柱式，工作臺為十字滑臺，適合加工盤類零件，一般具有3個直線運動坐標(biāo)軸，并可在工作臺上安置一個水平軸的數(shù)控轉(zhuǎn)臺（第4軸）來加工螺旋類零件。立式加工中心結(jié)構(gòu)簡單，占地面積小，價格低，配備各種附件后，可進(jìn)行大部分工件的加工。 龍門式加工中心，主軸多為垂直設(shè)置，尤其使用于大型或形狀復(fù)雜的工件，像航空、航天工業(yè)及大型汽輪機(jī)上的某些零件的加工都需要用這類多坐標(biāo)龍門式加工中心。 五面加工中心，這種加工中心具有立式和臥式加工中心的功能，在工件一次裝夾后，能完成除安裝面外的所有五個面的加工，這種加工方式可以使工件的形狀誤差降到最低，省去二次裝夾工作，從而提高生產(chǎn)效率，降低加工成本。 （2）按工藝用途分類有： 鏜銑加工中心，分為立式樘銑加工中心、臥式樘銑加工中心和龍門樘銑加工中心。其加工工藝是樘銑為主，適用于箱體，殼體以及各種復(fù)雜零件特殊曲線和曲面輪廓的多工序加工，適合多品種小批量生產(chǎn)。 復(fù)合加工中心，指五面復(fù)合加工，主軸頭可自動回轉(zhuǎn)，進(jìn)行立，臥加工，在主軸自動回轉(zhuǎn)后，在水平和垂直方向?qū)崿F(xiàn)知道變換。 （3）按特殊功能分類有： 單工作臺、雙工作臺加工中心； 單軸、雙軸、三軸及可換主軸箱的加工中心； 立式轉(zhuǎn)塔加工中心和臥式轉(zhuǎn)塔加工中心； 刀庫加主軸換刀加工中心； 刀庫接寫手加主軸換刀加工中心； 刀庫加機(jī)械手加雙主軸轉(zhuǎn)塔加工中心。 3、當(dāng)今數(shù)控機(jī)床的發(fā)展趨勢： 目前，隨著世界先進(jìn)制造技術(shù)興起，和超高速切削、超精密加工等技術(shù)的應(yīng)用，柔性制造系統(tǒng)的迅速發(fā)展和計算機(jī)集成系統(tǒng)的不斷成熟，對數(shù)控加工技術(shù)提出了更高的要求。當(dāng)今數(shù)控機(jī)床正在朝著以下幾個方向發(fā)展。 （1）.高速度、高精度化速度和精度是數(shù)控機(jī)床的兩個重要指標(biāo)，它直接關(guān)系到加工效率和產(chǎn)品質(zhì)量。目前，數(shù)控系統(tǒng)采用位數(shù)、頻率更高的處理器，以提高系統(tǒng)的基本運算速度。同時，采用超大規(guī)模的集成電路和多微處理器結(jié)構(gòu)，以提高系統(tǒng)的數(shù)據(jù)處理能力，即提高插補運算的速度和精度。并采用直線電動機(jī)直接驅(qū)動機(jī)床工作臺的直線伺服進(jìn)給方式，其高速度和動態(tài)響應(yīng)特性相當(dāng)優(yōu)越。采用前饋控制技術(shù)，使追蹤滯后誤差大大減小，從而改善拐角切削的加工精度。 為適應(yīng)超高速加工的要求，數(shù)控機(jī)床采用主軸電動機(jī)與機(jī)床主軸合二為一的結(jié)構(gòu)形式，實現(xiàn)了變頻電動機(jī)與機(jī)床主軸一體化，主軸電機(jī)的軸承采用磁浮軸承、液體動靜壓軸承或陶瓷滾動軸承等形式。目前，陶瓷刀具和金剛石涂層刀具已開始得到應(yīng)用。 （2）.多功能化配有自動換刀機(jī)構(gòu)(刀庫容量可達(dá)100把以上)的各類加工中心，能在同一臺機(jī)床上同時實現(xiàn)銑削、鏜削、鉆削、車削、鉸孔、擴(kuò)孔、攻螺紋等多種工序加工，現(xiàn)代數(shù)控機(jī)床還采用了多主軸、多面體切削，即同時對一個零件的不同部位進(jìn)行不同方式的切削加工。數(shù)控系統(tǒng)由于采用了多CPU結(jié)構(gòu)和分級中斷控制方式，即可在一臺機(jī)床上同時進(jìn)行零件加工和程序編制，實現(xiàn)所謂的“前臺加工，后臺編輯”。為了適應(yīng)柔性制造系統(tǒng)和計算機(jī)集成系統(tǒng)的要求，數(shù)控系統(tǒng)具有遠(yuǎn)距離串行接口，甚至可以聯(lián)網(wǎng)，實現(xiàn)數(shù)控機(jī)床之間的數(shù)據(jù)通信，也可以直接對多臺數(shù)控機(jī)床進(jìn)行控制。 （3）.智能化現(xiàn)代數(shù)控機(jī)床將引進(jìn)自適應(yīng)控制技術(shù)，根據(jù)切削條件的變化，自動調(diào)節(jié)工作參數(shù)，使加工過程中能保持最佳工作狀態(tài)，從而得到較高的加工精度和較小的表面粗糙度，同時也能提高刀具的使用壽命和設(shè)備的生產(chǎn)效率。具有自診斷、自修復(fù)功能，在整個工作狀態(tài)中，系統(tǒng)隨時對CNC系統(tǒng)本身以及與其相連的各種設(shè)備進(jìn)行自診斷、檢查。一旦出現(xiàn)故障時，立即采用停機(jī)等措施，并進(jìn)行故障報警，提示發(fā)生故障的部位、原因等。還可以自動使故障模塊脫機(jī)，而接通備用模塊，以確保無人化工作環(huán)境的要求。為實現(xiàn)更高的故障診斷要求，其發(fā)展趨勢是采用人工智能專家診斷系統(tǒng)。 （4）隨著計算機(jī)應(yīng)用技術(shù)的發(fā)展.數(shù)控編程自動化，目前CAD／CAM圖形交互式自動編程已得到較多的應(yīng)用，是數(shù)控技術(shù)發(fā)展的新趨勢。它是利用CAD繪制的零件加工圖樣，再經(jīng)計算機(jī)內(nèi)的刀具軌跡數(shù)據(jù)進(jìn)行計算和后置處理，從而自動生成NC零件加工程序，以實現(xiàn)CAD與CAM的集成。隨著CIMS技術(shù)的發(fā)展，當(dāng)前又出現(xiàn)了CAD／CAPP／CAM集成的全自動編程方式，它與CAD／CAM系統(tǒng)編程的最大區(qū)別是其