文档介绍：4 Planers are similar to shapers because both machines are primarily used to produce flat and angular surfaces. However, planers are capable of modating much larger work- pieces than the shaper. In planer operations the workpiece is mounted on the table which reciprocates (往复运动) ina horizontal plane providing a straight-line cutting and feed action. Single-point cutting tools are mounted on an overhead cross rail and along the vertically supported columns (柱状物) . The cutting tools are fed into or away from the workpiece on either the horizontal or vertical plane, thus being capable of four straight-line feed motions. 龙门刨床与刨床类似, 因为两者都用来加工平面或斜面。不同的是龙门刨床适合加工更大尺寸的工件。龙门刨床在加工过程中, 工件被安装在提供直线切削和进给运动的沿水平往复运动的工作台上。***被安装在上方的交叉导轨和垂直立柱上。***在水平方向和垂直方向朝向工件或远离工件做进给运动,因此***有四个直线进给运动。 7 Grinding machines utilize abrasive (研磨料) grains, bonded into various shapes and sizes of wheels and belts to be used as the cutting agent ( 介质) . Grinding operations are used to impart ( 给予, 传递) a high-quality surface finish on the workpiece. In addition, the dimensional accuracy of the workpiece is improved since tolerances of