工件以一平面和两孔定位时,其中主要孔用圆柱销固定,而另一孔采用菱形销;并令圆柱销直径的名又尺寸等於主要孔直径的名义尺寸。工件沿中心线纵长方向最大可能的移动将等於上△D十△1D之和。其中△D为主要孔直径的公差,而上△1D圆柱销直径的公差。 由於孔和销的中心间距存在有公 When the work piece is positioned with a flat surface and two holes, the main hole is fixed by a cylindrical pin and the other hole is a diamond pin. The diameter of the pin is equal to the nominal size of the main hole diameter. The maximum possible lengthwise movement of the workpiece along the center line will be equal to the sum of ΔD + ΔD. Where ΔD is the tolerance of the principal hole diameter, and the tolerance of the diameter of the 1D cylindrical pin. There is a male due to the center distance between the hole and the pin