外文翻譯.wps

1、中國(guó)地質(zhì)大學(xué)長(zhǎng)城學(xué)院 中國(guó)地質(zhì)大學(xué)長(zhǎng)城學(xué)院本科畢業(yè) 本科畢業(yè)設(shè)計(jì) 設(shè)計(jì)外文資料翻譯 外文資料翻譯系 別： 系 別： 工程技術(shù)系 專 業(yè)： 專 業(yè)： 機(jī)械設(shè)計(jì)制造及其自動(dòng)化 姓 名： 姓 名： 王碩學(xué) 學(xué) 號(hào)：號(hào)： 052116112015 2015年 年 4 月 月 4 日2機(jī)械設(shè)計(jì)制造及自動(dòng)化專業(yè)畢業(yè)設(shè)計(jì)（論文）外文翻譯machine provides three m

2、otions relative to the cutter. A four motion may be providedby swiveling the table around a vertical axis provided on the saddle.Fixed-bed milling machines are designed to provide more rigidity than the kneeand column ty

3、pe. The table is mounted directly on the machine base, which providesthe rigidity necessary for absorbing heavy cutting load, and allows only longitudinalmotion to the table. Vertical motion is obtained by moving the ent

4、ire cutting head.Tracer milling is characterized by coordinated or synchronized movements ofeither the paths of the cutter and tracing elements, or the paths of the workpiece andmodel. In a typical tracer mill the traci

5、ng finger follow the shape of the masterpattern, and the cutter heads duplicate the tracer motion.The following are general design considerations for milling:1. Wherever possible, the part should be designed so that a ma

6、ximum number ofsurfaces can be milled from one setting.2. Design for the use of multiple cutters to mill several surfaces simultaneously.3. The largest flat surface will be milled first, so that all dimensions are bestr

7、eferred to such surface.4. Square inside corners are not possible, since the cutter rotates.Grinding Machines and Special Metal-removal ProcessRandom point-cutting tools include abrasives in the shape of a wheel, bonded

8、to abelt, a stick, or simply suspended in liquid. The grinding process is of extremeimportance in production work for several reasons.1.It is most common method for cutting hardened tool steel or other heat-treatedsteel.

9、 Parts are first machined in the un-heat-treated condition, and then ground to thedesired dimensions and surface finish.2.It can provide surface finish to 0.5µm without extreme cost.3.The grinding operation can assu

10、re accurate dimensions in a relatively shorttime, since machines are built to provide motions in increments of ten-thousandths ofan inch, instead of thousandths as is common in other machines. 4.Extremely small and thin

11、parts can be finished by this method, since lightpressure is used and the tendency for the part to deflect away from the cutter isminimized.On a cylindrical grinding machine the grinding wheel rotates between 5500 and650