【正文】 動。也就是說，自由振動是在彈性系統(tǒng)固有彈性恢復(fù)力的作用下產(chǎn)生的，而固有頻率則是系統(tǒng)的一個特性。 能量耗散以某種方式與系統(tǒng)的部件或元件之間的相對運動有關(guān)，它是由于某種類型的磨擦引起的。短的錐面或柱面也可以仿形切削。其它所有金屬切削工藝都是這 5 種基本工藝的變形。粗加工工序的目的是盡可能迅速且高效地去除大量的材料，在工件上只留下少量的材料給精加工工序。由頂尖獲得的對正不能維持而且爪的壓力可能損壞頂尖孔、車床頂尖甚至車床主軸。內(nèi)槽是用與外部開槽工具相擬的工具切削。這允許在孔的“后側(cè)”進行鏜削切削，在車床前面，從操作者的位置易于看到孔。 型心孔和鉆的孔有時相對于車床的旋轉(zhuǎn)是偏心的。一個車床夾頭夾在工件上；然后由安裝在主軸前端的撥盤一起帶動。可以通過把它們與留聲機的唱針和唱片相比較給出其定義。在銑削作業(yè)中，有許多切削刃的旋轉(zhuǎn)銑刀與工件相接合，這種工件相對銑刀運動緩慢。機器表面的幾何形狀取決于刀具的形狀 以及加工操作過程中刀具的路徑。但是，電學(xué)上，收音機和電視機的接收器則被設(shè)計成在共振頻率時工作。每個單位時間內(nèi)的循環(huán)數(shù)目被稱為頻率。與振動有關(guān)的物理量是相互關(guān)聯(lián)的加速度，速度和位移。 2. it provedes relative motion between the workpiece and the cutting tools。 lapping, superfinishing, polishing, and buffing are avariants of grinding or abrasive removal operations. Therefore, there are only four types of basic machine tools, which use cutting tools of specific controllable feometry: , , machines, and machines. The frinding process forms chips, but the geometry of the barasive grain is uncontrollable. The amount and rate of material removed by the various machining processes may be large, as in heavy truning operations, or extremely small, as in lapping or superfinishing operations where only the high spots of a surface are removed. A machine tool performs three major functions: rigidly supports the workpiece or its holder and the cutting tool。 一個物體或一種材料在振動時，它相對于靜平衡位置的位置變化或位移是周期性的。在任何一個周期內(nèi)所完成的運動，被子稱為一個循環(huán)。在這種臨界條件下，機械系統(tǒng)中出現(xiàn)具有危險性的在振幅和高應(yīng)力。切屑是廢棄的產(chǎn)品，與其工件相比相當(dāng)短但是比未切屑的部分有相對的增加。不管是鉆頭轉(zhuǎn)動還是工件旋轉(zhuǎn)，切削刃與工件之間的相 對運動是一個重要因數(shù)。它們都影響切削力、功率和對金屬切削的速率。 通過將工件支承在兩個頂尖之間可以獲得非常精密的結(jié)果。測量儀表或內(nèi)千分卡尺可用于直接測量直徑。正常的車削世削是在主軸逆時針轉(zhuǎn)動時進行的；鏜削切削是在主軸順時針方向或“向后”轉(zhuǎn)動時進行的。鏜削內(nèi)槽的步驟非常類似于肩部的步驟。幾乎被獨自用在大量生產(chǎn)工件上的補償或浮動爪式卡盤是上述的一個例外。精加工工序用以獲得工件最終的大小、形狀和表面光潔度。例如：鏜削是內(nèi)部的車削；鉸削、錐體車削和平底锪孔則修改鉆孔，與鉆削有關(guān)；滾齒與切齒是基本銑削作業(yè)；弓鋸削和拉削是刨削和珩磨的一種形式；而研磨、超精加工、拋光和磨光則是磨削和研磨切屑作業(yè)的各種變化形式。 常常需要的是平坦的或平的表面。例如，在結(jié)構(gòu)中，材料內(nèi)部的磨擦和由空氣可液體阻力等造成的外部磨擦被稱為“粘性”阻尼，在這里假定阻力與運動部件之間的速度成正比。 強迫振動是在外力的 激勵（或者外部的振蕩性干擾）下產(chǎn)生的。由于需要能量才能產(chǎn)生振動，因此，振動消耗了能量，降低了機器和機構(gòu)的效率。 namely, rough boring and finish boring. The objective of the roughboring operation is to remove the excess metal rapidly and efficiently, and the objective of the finishboring operation is to obtain the desired size, surface finish, and location of the hole. The size of the hole is obtained by using the trialcut procedure. The diameter of the hole can be measured with inside calipers and outside micrometer calipers. Basic Measuring Insteruments, or inside micrometer calipers can be used to measure the diameter directly. Cored holes and drilled holes are sometimes eccentric wwith respect to the rotation of the lathe. When the boring tool enters the work, the boring bar will take a deeper cut on one side of the hole than on the other, and will deflect more when taking this deeper cut,with the result that the bored hole will not be concentric with the rotation of the work. This effect is corrected by taking several cuts through the hole using a shallow depth of cut. Each succeeding shallow cut causes the resulting hole to be more concentric than it was with the previous cut. Before the final, finish cut is taken, the hole should be concentric with the rotation of the work in order to make certain that the finished hole will be accurately located. Shoulders, grooves, contours, tapers, and threads are bored inside of holes. Internal grooves are cut using a tool that is similar to an external grooving tool. The procedure for boring internal shoulders is very similar to the procedure for turning shoulders are faced with the boring tool positioned with the nose leading, and using the cross slide to feed the tool. Internal contours can be machined using a tracing attachment on a lathe. The tracing attachment is mounted on the cross slide and the stylus follows the outline of the master profile plate. This causes the cutting tool to move in a path corresponding to the profile of the master profile plate. Thus, the profile on the master profile plate is reproduced inside the bore. The master profile plate is accurately mounted on a special slide which can be precisely adjusted in two dirctions, in two directionsm, in order to align the cutting tool in the correct relationship to the work. This lathe has a camlick type of spindle nose which permits it to take a cut when rotating in either direction. Normal turning cuts are taken with the spindle rotating counterclockwise. Thie boring cut is taken with the spindle revolving in a clockwise direction, or “backwards”. This permits the boring cut to be taken on the “back side” of the bore which is easier to see from the operator’sposition in front of the lathe. This should not be done on lathes having a threaded spindle nose because the cutting force will tend to unscrew the chuck. 中文翻譯