在机床制造中经常有些箱体零件上需要加工孔的工作。这些孔往往是非常精密,孔距之间要求着较严格的允差,因为这些箱体一般都装有复杂的齿轮传动系统,它的加工精密程度直接影响着各传动系统的运转情况。在小批生产中通常是在精密镗床上藉助镗模一孔一孔加工的,因此往往难于保持 In the manufacture of machine tools often need to work some holes on the hole work. These holes are often very precise, with tight tolerances being required between the holes because these boxes are generally equipped with complex gear trains and their precision of machining directly affects the operation of the drivelines. In small batch production, it is often difficult to maintain a precision boring machine with a hole in a boring die.