一、镗铣床从固定结构布局向可变结构布局的发展国内外现有的镗铣床布局可以说都是固定结构布局的。这种机床一旦设计制造完成后,其结构布局是不可变的。实践证明:这种结构布局的固定性往往对被加工件型谱及其加工要求的多样性、可变性无法完全适应,有时甚至形成无法克服的矛盾。在设计机床时,往往照顾到一个方面的要求,又勿略了另一方面的要求。例如 First, the boring and milling machine from the fixed structure layout to the development of variable structure layout Domestic and foreign existing boring and milling machine layout can be said that the fixed structure layout. Once the design and manufacture of this machine tool is completed, its structural layout is immutable. Practice has proved that: the structural layout of the fixed nature of the workpiece is often the type and processing requirements of the diversity, variability can not be fully adapted, and sometimes even form an insurmountable contradiction. In the design of machine tools, tend to take care of one aspect of the requirements, but do not skip the other requirements. E.g