数控机床特殊点的探讨

The discussion on the specific points of the numerical control machine

在数控加工中如果工件编程坐标系的原点建立在工件表面上,那么当把工件放在数控机床上也要在工件表面上建立相同的坐标系,这样当利用试切法对刀在数控机床上建立与工件编程坐标系相同的工件坐标系时,当刀具底面与工件表面接触时,一般就说工件坐标系的原点就建立在工件表面上,但是为什么当我们使用不同长度的刀具进行不同表面加工时,就不能直接使用原来的工件坐标系,要进行刀具长度补偿才能使用原来的工件坐标系,本文就这一问题首先对数控机床的机床原点、机械原点、装刀装置特征点等特殊点进行了的讨论,其次通过建立工件坐标系论述了机床坐标系与工件坐标系的关系,这对深入理解数控加工、数控编程及工件坐标系的建立具有一定的指导性作用。

In numerical control processing, the two coordinate systems, that are work piece programming coordinate system and work piece coordinate system, are established first on work piece surface. These two kinds of coordinate system will be in superposition when the trial cut method is employed to set the tool. The cutting tools length compensations are used to finish the different faces of the work piece in these two kinds of coordinate systems with the different length cutting tools. The reason that why used the cutting tool length compensation are explained in this paper, by the discussion of the numerical control machine specific points that include the origin of machine tool, the origin of machine and the feature point of tool post. The relation between the machine tool coordinate system and the work piece coordinate system is explained by building the work piece coordinate system. Comprehending this relationship will be instructive for understanding numerical control machining, numerical control programming and building the work piece coordinate system.