Three principles of nc machining technology
1.The principle of maximum process concentration and location
According to the distance between the processing parts and the cutting point, in general, the parts close to the
cutting point are processed first, and the parts far away from the cutting point are processed later, so as to
shorten the moving distance of the cutting tool and reduce the time of empty travel. For turning, it is beneficial
to keep the rigidity of blank or semi-finished products and improve the cutting conditions. For both milling plane
and boring parts processing, can be milling plane before boring sequence. Because the cutting force is large when
milling the plane, the parts are prone to deformation, first milling the surface before boring, so that it has a
period of time to recover, after the recovery of deformation before boring, is conducive to ensuring the machining
accuracy of the hole, secondly, if the first boring before milling the plane, hole mouth will produce burr, flying
edge, affect the assembly of the hole.
The principle of first near and then far, first face and then hole
Generally on nc machine tools, especially on the machining center processing parts, processes can be concentrated
to the greatest extent, namely the parts in a clamping should as far as possible to complete the digit-controlled
lathe processing most or all of the process, nc machining tend to process, can reduce the number of machine tool
and workpiece clamping, reduce unnecessary positioning error and high productivity.
3.First rough, then fine
When carrying out numerical control machining, according to the parts of the processing precision, stiffness and
deformation and other elements to divide the process, should follow the rough, fine processing is separated to
divide the process, that is, after the first complete rough machining, then semi-finish machining, finish
machining. For a processed surface, it should be finished in the order of roughing - semi-finishing - finishing.
Rough machining should be in the guarantee of machining quality, tool durability and machine tool - fixture - tool
- workpiece technology system rigidity allowed conditions, give full play to the performance of the machine tool
and cutting performance of the tool, try to use a larger number of cutting times to get the parts before finishing
as evenly as possible machining condition. The precision and surface quality of the parts are mainly guaranteed
when finishing, so the final contour of the parts should be finished by the last continuous finishing.