【正文】 it is numbered 3 in the provides clearance between work and tool so that its cut surface can flow by with minimum rubbing against the save time, a portion of the end flank of the tool may sometimes be left unground, having been previously forged to such case, this endclearance angle, numbered 4, measured to the end flank surface below the ground portion, would be larger than the relief the end cutting edge is oblique to the relief angle is then best measured in a plane normal to the end cutting edge perpendicular to the base of the clearance permits the tool to advance more smoothly into the siderelief angle, indicated as 5, is measured between the side flank, just below the cutting edge, and a line through the cutting edge perpendicular to the base of the clearance permits the tool to advance more smoothly into the 6 is the endcuttingedge angle measured between the end cutting edge and a line perpendicular to the side of the tool angle prevents rubbing of the cut surface and permits longer tool sidecuttingedge angle, numbered 7, is the angle between the side cutting edge and the side of the tool true length of cut is along this the angle determines the distribution of the cutting greater the angle, the longer the tool life。第二篇：畢業(yè)設(shè)計(jì)_英語論文翻譯┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ 裝 ┊ ┊ ┊ ┊ ┊ 訂 ┊ ┊ ┊ ┊ ┊ 線 ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊畢業(yè)設(shè)計(jì)（論文）報(bào)告紙LATHESThe basic machines that are designed primarily to do turning, facing and boring are called little turning is done on other types of machine tools, and nine can do it with equal lathe can do boring, facing, drilling, and reaming in addition to turning, their versatility permits several operations to be performed with a single setup of the accounts for the fact that lathes of various types are more widely used in manufacturing than any other machine in various forms have existed for more than two thousand lathes date from about 1797, when Henry Maudsley developed one with a provided controlled, mechanical feed of the ingenious Englishman also developed a changegear system that could connect the motions of the spindle and leadscrew and thus enable threads to be essential ponents of a lathe are depicted in the block diagram of are the bed, headstock assembly, tailstock assembly, carriage assembly, quickchange gear box, and the leadscrew and feed bed is the backbone of a is usually made of wellnormalized or aged gray or nodular cast iron and provides a heavy, rigid frame on which all the other basic ponents are sets of parallel, longitudinal ways, inner and outer, are contained on the bed, usually on the upper makers use an inverted Vshape for all four ways, whereas others utilize one inverted V and one flat way in one or both several other ponents are mounted and/or move on the ways they must be made with precision to assure accuracy of , proper precaution should be taken in operating a lathe to assure that the ways are not inaccuracy in them usually means that the accuracy of the entire lathe is ways on most modern lathes are surface hardened to offer greater resistance to wear and headstock is mounted in a fixed position on the inner ways at one end of the lathe provides a powered means of rotating the work at various consists, essentially, of a hollow spindle, mounted in accurate bearings, and a set of transmission gearssimilar to a truck transmissionthrough which the spindle can be rotated at a number of lathes provide from eight to eighteen speeds, usually in a geometric ratio, and on modern lathes all the共 14 頁 第 1 頁┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ 裝 ┊ ┊ ┊ ┊ ┊ 訂 ┊ ┊ ┊ ┊ ┊ 線 ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊畢業(yè)設(shè)計(jì)（論文）報(bào)告紙speeds can be obtained merely by moving from two to four increasing trend is to provide a continuously variable speed range through electrical or mechanical the accuracy of a lathe is greatly dependent on the spindle, it is of heavy construction and mounted in heavy bearings, usually preloaded tapered roller or ball longitudinal hole extends through the spindle so that long bar stock can be fed through size of this hole is an important size dimension of a lathe because it determines the maximum size of bar stock that can be machined when the material must be fed through the inner end of the spindle protrudes from the gear box and contains a means for mounting various types of chucks, face plates, and dog plates on small lathes often employ a threaded section to which the chucks are screwed, most large lathes utilize either camlock or keydrive taper provide a largediameter taper that assures the accurate alignment of the chuck, and a mechanism that permits the chuck or face plate to be locked or unlocked in position without the necessity of having to rotate these heavy is supplied to the spindle by means of an electric motor through a Vbelt or silentchain modern lathes have motors of from 5 to 15 horsepower to provide adequate power for carbide and ceramic tools at their high cutting tailstock assembly consists, essentially, of three lower casting fits on the inner ways of the bed and can slide longitudinally thereon, with a means for clamping the entire assembly in any desired upper casting fits on the lower one and can be moved transversely upon it on some type of keyed transverse motion permits aligning the tailstock and headstock spindles and provides a method of turning third major ponent of the assembly is the tailstock is a hollow steel cylinder, usually about 2 to 3 inches in diameter, that can be moved several inches longitudinally in and out of the upper casting by means of a handwheel and open end of the quill hole terminates in a Morse taper in which a lathe center, or various tools such as drills, can be graduated scale, several inches in length, usually is engraved on the outside of the quill to aid in controlling its motion in and out of the upper locking device permits clamping the quill in any desired carriage assembly provides the means for mounting and