【導(dǎo)讀】車床主要是為了進(jìn)行車外圓、車端面和鏜孔等項(xiàng)工作而設(shè)計(jì)的機(jī)床。中完成幾種加工。車床的基本部件有：床身、主軸箱組件、尾座組件、溜板組件、絲杠和光杠。床身是車床的基礎(chǔ)件。它能常是由經(jīng)過充分正火或時(shí)效處理的灰鑄鐵或者球墨。身上有內(nèi)外兩組平行的導(dǎo)軌。導(dǎo)軌要經(jīng)過精密加工以保證其直線度精度。為了抵抗磨損和擦。導(dǎo)軌上的任何誤差，常常意味著整個(gè)機(jī)床的精度遭到破壞。械的裝置進(jìn)行無級(jí)變速。安裝在預(yù)緊后的重型圓錐滾子軸承或球軸承中。尾座組件主要由三部分組成。尾座的第三個(gè)組成部分是尾座套筒。通過手輪和螺桿，尾座套筒可以在尾座體中縱向移。此外，需要技術(shù)熟練的工人來操作普通車床，這種工人。發(fā)展數(shù)控技術(shù)是為了克服人類操作者的局限性，而且它確實(shí)完成了這項(xiàng)工作。數(shù)控可以使生產(chǎn)廠家承擔(dān)那些對(duì)于采用人工控制的機(jī)床和工藝來說，削刀具的形狀和規(guī)定必要的運(yùn)動(dòng)。易損壞的紙帶顯然不能。承受嚴(yán)配的車間環(huán)境和這種重復(fù)使用。

　　

【正文】 to run the tape through the reader as many times as there were parts to be produced. Fortunately, puter technology became a reality and soon solved the problems of NC associated with punched paper and plastic tape. The development of a concept known as direct numerical control (DNC) solved the paper and plastic tape problems associated with numerical control by simply eliminating tape as the medium for carrying the programmed instructions. In direct numerical control, machine tools are tied, via a data transmission link, to a host puter. Programs for operating the machine tools are stored in the host puter and fed to the machine tool an needed via the data transmission linkage. Direct numerical control represented a major step forward over punched tape and plastic tape. However, it is subject to the same limitations as all technologies that depend on a host puter. When the host puter goes down, the machine tools also experience downtime. This problem led to the development of puter numerical control. 3 Turning The engine lathe, one of the oldest metal removal machines, has a number of useful and highly desirable attributes. Today these lathes are used primarily in small shops where smaller quantities rather than large production runs are encountered. The engine lathe has been replaced in today’s production shops by a wide variety of automatic lathes such as automatic of singlepoint tooling for maximum metal removal, and the use of form tools for finish on a par with the fastest processing equipment on the scene today. Tolerances for the engine lathe depend primarily on the skill of the operator. The design engineer must be careful in using tolerances of an experimental part that has been produced on the engine lathe by a skilled operator. In redesigning an experimental part for production, economical tolerances should be used. Turret Lathes Production machining equipment must be evaluated now, more than ever before, this criterion for establishing the production qualification of a specific method, the turret lathe merits a high rating. In designing for low quantities such as 100 or 200 parts, it is most economical to use the turret lathe. In achieving the optimum tolerances possible on the turrets lathe, the designer should strive for a minimum of operations. Automatic Screw Machines Generally, automatic screw machines fall into several categories。 singlespindle automatics, multiplespindle automatics and automatic chucking machines. Originally designed for rapid, automatic production of screws and similar threaded parts, the automatic screw machine has long since exceeded the confines of this narrow field, and today plays a vital role in the mass production of a variety of precision parts. Quantities play an important part in the economy of the parts machined on the automatic screw machine. Quantities less than on the automatic screw machine. The cost of the parts machined can be reduced if the minimum economical lot size is calculated and the proper machine is selected for these quantities. Automatic Tracer Lathes Since surface roughness depends greatly on material turned, tooling , and feeds and speeds employed, minimum tolerances that can be held on automatic tracer lathes are not necessarily the most economical tolerances. In some cases, tolerances of are held in continuous production using but one cut . groove width can be held to on some parts. Bores and singlepoint finishes can be held to . On highproduction runs where maximum output is desirable, a minimum tolerance of is economical on both diameter and length of turn.