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

When machining precision parts of small and medium-sized batches of workpieces, a combination fixture 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 for the first time is generally cumbersome, and there are also inconveniences such as inconvenient chip removal.

   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-shaped slots or keyways made of components with standard spacing. By positioning the key in the keyway, 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-type combination jig can be determined by the keys that can slide along the slot or the positioning of the keys in the slot, it has 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 a threaded connection. Compared with slot system combined fixtures, the hole system combined fixture used in precision parts processing has the advantages of good rigidity, low manufacturing cost, short assembly time, and reliable positioning; its disadvantages are poor assembly flexibility and components on the fixture The position is inconvenient for stepless adjustment.