CNC processing requires us to follow a scientific method. Whether it is part clamping method, fixture selection or processing sequence, the clamping method for processing parts in Shenzhen CNC machine tool processing should also reasonably select the positioning datum and clamping scheme. When selecting fine datum, the two principles of datum unification and datum overlap shall be generally followed. In addition to these two principles, we should also consider:
a. The machining of all surfaces shall be completed in one positioning clamping as far as possible. Therefore, the positioning method that facilitates the machining of all surfaces shall be selected.
b. When the workpiece is clamped at one time, all surfaces of the workpiece shall be machined.
c. When determining the placement position of the workpiece on the workbench, the influence of machining, tool length and stiffness on machining quality should be considered.
d. Fixtures used in control processing shall be adjustable by assembling general components as much as possible to shorten the production
preparation cycle.
Arrange processing sequence
When arranging the processing sequence, the basic principles must be followed, including surface first, hole second, rough first and fine second. In addition to these basic principles, we should also follow the following principles, as follows:
A. Centralized processing shall be carried out according to tools to avoid repeated use of the same tool and reduce the number and time of tool change.
B. For the hole system with high coaxiality requirements, all processing of the hole system shall be completed after one positioning, and then the hole system at other coordinate positions shall be processed to eliminate the error caused by repeated positioning and improve the coaxiality of the hole system.
c. Select the determined tool point and tool change point, which should not be replaced after confirmation.
There are two main steps in clamping, namely clamping and positioning. When clamping the traditional machine tool, the number of clamping times increases due to the limitation of the machine tool capacity. When clamping the CNC machine tool, multiple surfaces can be processed at one time, thus reducing the clamping error. In the process of clamping, special fixtures are used to facilitate positioning and clamping, but the cost is very high. If the number of pieces to be processed is large, the cost shared in the fixture cannot be ignored. Therefore, attention should be paid to this when designing and using special fixtures. CNC machining can be debugged through instruments to meet the requirements of positioning standards. This process does not require special fixtures, and only ordinary pressing elements can complete the clamping, thus greatly reducing the cost.
