The field of CNC machine tool processing is not unfamiliar with fixtures. The processing of CNC machine tools requires fixtures to assist and stabilize, ensure the accuracy of the processed parts, reduce the labor intensity of workers, and improve the production efficiency. There are many kinds of fixtures, and different fixtures are used to process different workpieces. The following is a brief introduction to the specific functions of fixtures and the commonly used fixtures.

1、 What are the functions of fixtures

1. The machining accuracy of the workpiece can be stably guaranteed: when the workpiece is clamped by the clamp, the position accuracy of the workpiece relative to the tool and the machine tool is guaranteed by the clamp. The machining accuracy of a batch of workpieces is not affected by the technical level of workers.

2. It can reduce auxiliary working hours and improve labor productivity: the workpiece can be quickly positioned and clamped without alignment. Significantly reducing auxiliary man hours; Clamping the workpiece with a jig improves the rigidity of the workpiece, so the cutting amount can be increased. It can use multi piece and multi station clamps to clamp workpieces and adopt high-efficiency clamping mechanism. These factors are conducive to improving labor productivity.

3. It can expand the use range of the machine tool and realize multi-function of one machine: the use of special fixtures can change the use of the original machine tool and expand the use range of the machine tool to realize multi-function of one machine. For example, after the boring jig is installed on the lathe or the radial drilling machine, the hole system of the box can be bored; The lathe can also be changed into a broaching machine through a special fixture to give full play to the role of a general machine tool.

4. Reduce the labor intensity of workers: it is convenient and fast to clamp workpieces with clamps. When pneumatic and hydraulic clamping devices are used, the labor intensity of workers can be reduced.

2、 Introduction to commonly used fixture types

1. Wan modular fixture is suitable for small and medium-sized workpieces in small batch production or development to be milled on a CNC milling machine.

2. Special milling fixture is specially designed and manufactured for one or several similar workpieces. Generally, it is adopted when it is necessary for mass production or development.

3. The multi station fixture can hold multiple workpieces at the same time, which can reduce the number of tool changes and facilitate one-sided processing. Loading and unloading of workpieces on one side can shorten the preparation time. It is more suitable for medium batch production.

4. Pneumatic or hydraulic fixtures are suitable for the production of large quantities of workpieces, and the use of other fixtures is particularly laborious and laborious. It can reduce the labor intensity of workers and improve productivity, but the structure of such fixtures is complex. The cost is often high and the manufacturing cycle is long.

5. Vacuum fixture is suitable for workpieces with large positioning plane or large sealable area. Some CNC milling machines (such as wallboard milling machines) are equipped with a general vacuum platform. When installing workpieces, rectangular blanks with regular shapes are processed. It can be directly embedded in the sealing groove of the clamp with a hollow or solid circular section with special rubber strips with certain size requirements. Put the blank on and start the vacuum pump to clamp the blank.