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在机械加工中,有不少工件是采取“一面两銷”定位来加工的,如內燃机中的缸体、缸盖、离合壳等。在此种定位方法中,对夹具来說,影响工件定位精度的主要因素是两定位銷的尺寸及其位置精度;对工件本身来說則是工件定位孔的尺寸及其位置精度。在夹具两定位銷中,一定位銷(圆柱銷)是以工件工艺孔的下限尺寸作为該定位銷的公称尺寸,按其对工件的精度要求取公差d_b或d_c。对于直径在
In machining, there are a lot of work is to take “one side two pins” positioning to processing, such as internal combustion engine cylinder block, cylinder head, clutch shell. In this positioning method, the fixture, the main factor affecting the positioning accuracy of the workpiece is the size of the two pins and their position accuracy; the workpiece itself is the size of the workpiece positioning hole and its position accuracy. In the fixture two positioning pins, a positioning pin (cylindrical pin) is the lower limit of the size of the workpiece hole as the nominal size of the positioning pin, according to the accuracy of the workpiece to take tolerance d_b or d_c. For diameter in