Clamping method for machining precision parts of small and medium batch workpieces

When processing precision parts of small and medium-sized batches of workpieces, combined fixtures can be used for clamping. The combination fixture has the characteristics of disassembly and reassembly, so the combination fixture is a reusable special fixture system. However, there are many links between the components of the combined fixture, and the rigidity and accuracy of the fixture are inferior to other fixtures. Generally, when using combined fixtures, the machining dimensional accuracy can only reach IT8~IT9 level. Secondly, the use of combined fixtures is cumbersome for the first time, and it is inconvenient to remove chips.

At present, the commonly used combined fixture system includes slot system combined fixture system and hole system combined fixture system.

Selection of fixtures for small and medium batch parts processing

   1. Slot system combined fixture

   The slot system combined fixture used for precision parts processing refers to the parallel and vertical T-slots or key slots with standard spacings made on the components. By positioning the keys in the key slots, the exact position of each component in the fixture can be accurately determined. The components are connected or fastened with threads. Since the mutual positions of the components of the slot system combination fixture can be determined by the keys that can slide along the slot or the positioning of the keys in the slot, they have good adjustability.

   2. Hole system combined fixture

   The hole system combined clamp means that the mutual position between the clamp elements is determined by the hole and the positioning pin, and the connection between the components is still fastened with threaded connections. Compared with the slot-based combined fixture, the hole-based combined fixture used in precision parts processing has the advantages of good rigidity, low manufacturing cost, short assembly time, and reliable positioning; its disadvantage is that the assembly flexibility is poor, and the components on the fixture The position is inconvenient for stepless adjustment.