1, The concept of fixture: in the process of machining, in order to ensure the accuracy of processing, fixed workpiece, so that the position of the location to accept the processing or testing of the process equipment collectively referred to as machine tools fixture, referred to as fixture.
2. Requirements for clamping devices:
The clamping process shall not destroy the position of the workpiece in the fixture.
clamping force to be appropriate, not only to ensure that the workpiece in the process of the stability of positioning, but also to prevent the clamping force too large damage to the workpiece surface or the workpiece produced too much clamping deformation.
3 Operation Safety, labor-saving.
Classification of fixture
According to the type of machine tool: Lathe fixture, milling fixture, drilling jig, boring jig, machining center fixture, other machine tool fixture
According to the Working power source: manual fixture, pneumatic clamp, hydraulic clamp, electric fixture, magnetic fixture, vacuum fixture, automatic clamping fixture
According to the general degree of fixture of the machine tool:
① General fixture can process different workpiece in a certain range of fixture, such as the lathe on the three-claw self-centering chuck, four-jaw single dynamic Chuck. Milling machine on the flat mouth vice, split Head, rotary table.
Use of the occasion, because the use of general fixture clamping workpiece is time-consuming, complex operation, low production efficiency, and difficult to clamp. Therefore, the general fixture is mainly used in single piece of small batch production, in the product fixed mass production rarely use general fixture, and the use of high efficiency of the special fixture.
② Special fixture is specially designed for a certain work process of a workpiece. High positioning precision for mass production.
The ③ group fixture is designed according to the principle of group technology. Fixture for group processing. As long as the fixture part of the components slightly changed, you can process the different components in the group. Bearing
The ④ modular fixture is assembled into a fixture that is easy to connect and disassemble by the standard fixture parts that can be recycled. For new product trial and many varieties of small batch production.
⑤ accompanying fixture is a fixture used on the automatic line.
4 The role of the fixture
1 to ensure the workpiece machining accuracy
2 Improve labor productivity and reduce processing cost
3 Enlarge machine tool process range and change machine tool use
4 improve working conditions and ensure production safety.