Focus on CNC lathe
After selecting the processing method and dividing the process, the next step is to reasonably arrange the sequence of the process. The machining process of the parts usually includes cutting process, heat treatment process and auxiliary process. Reasonable arrangement of the order of cutting process, heat treatment and auxiliary process, and solving the connection problem between processes can improve the processing quality and productivity of the parts and reduce the processing cost. In the CNC lathe processing parts, should be divided into processes according to the principle of process concentration, the arrangement of parts turning processing order generally follows the following principles.
1. CNC lathe in the parts processing first coarse and then fine
According to the order of rough turning → semi-finishing turning → finishing turning, gradually improve the machining accuracy of the parts. Rough turning will cut off most of the machining margin on the surface of the workpiece in a shorter period of time, which not only improves the metal removal rate, but also meets the uniformity requirements of the finish turning margin. If the uniformity of the residual left after rough turning does not meet the requirements of finishing, semi-finishing turning should be arranged in order to make the finishing residual small and uniform. When finishing turning, the tool is finished along the contour of the part at one time to ensure the machining accuracy of the part.
2. CNC lathe in the parts processing first near and then far
The far and near mentioned here is according to the distance of the processing part relative to the tool change point. Usually in rough machining, the parts near the tool change point are processed first, and the parts far from the tool change point are processed afterwards, in order to shorten the tool movement distance, reduce the empty travel time, and help to maintain the rigidity of the blank or semi-finished parts and improve their cutting conditions.
3. CNC lathe in the parts processing inside and outside cross
For parts with both inner surface (inner type, inner cavity) and outer surface, when arranging the processing sequence, the inner and outer surface should be roughly processed first, and then the inner and outer surface should be finely processed.
When machining the inner and outer surfaces, the inner type and cavity are usually machined first, and then the outer surface is machined. The reason is that it is more difficult to control the size and shape of the inner surface, the tool rigidity is correspondingly poor, the durability of the tool tip (edge) is easily affected by cutting heat and reduced, and it is more difficult to remove the chips in the processing.
4. CNC lathe in the parts processing tool concentration
Tool concentration refers to the use of a tool after processing the corresponding parts, and then change another tool to process the corresponding other parts, in order to reduce the empty stroke and tool change time.
5. CNC lathe in the parts processing base surface first
The surface used as the fine reference should be processed first, because the more accurate the surface as the positioning reference, the smaller the clamping error. For example, when processing shaft parts, always process the center hole first, and then process the outer surface and end face with the center hole as the fine reference.
CNC lathe in the parts processing to determine the feed route
Feed route refers to the path that the tool starts moving from the starting point until it returns to the point and ends the processing program, including the path of cutting processing and the non-cutting empty stroke such as tool introduction and cutting out.
1. CNC lathe in the parts processing tool introduction, cutting out
When processing on the CNC lathe, especially fine turning, to properly consider the tool attraction, cut out route, try to make the tool tip along the contour of the tangential direction of the introduction, cut out, so as to avoid sudden changes in cutting force and elastic deformation, resulting in a smooth connection contour surface scratches, sudden changes in shape or stagnant tool marks and other problems.
2. CNC lathe in the parts processing to determine the shortest empty stroke route
Determine the shortest empty stroke route in addition to rely on a large number of practical experience, should be good at analysis, if necessary, can be supplemented by some simple calculations. In the manual preparation of more complex contour machining program, the programmer (especially beginners) will sometimes finish processing each tool by executing the "return to zero" (i.e., return to the tool change point) instruction, so that it returns to the tool change point position, and then execute the subsequent program. This will increase the distance of the tool path, thus greatly reducing productivity. Therefore, the "return to zero" instruction should not be used when executing the retreat action without changing the tool. When arranging the tool route, the distance between the end of the previous tool and the starting point of the next tool should be shortened as much as possible in order to meet the requirements of the shortest tool route. CNC lathe tool change point position to change the tool does not touch the workpiece as the principle.
3. CNC lathe in the parts processing to determine the shortest cutting feed route
Short cutting feed route can effectively improve productivity and reduce the amount of tool wear. In the arrangement of roughing or semi-finishing cutting feed route, should take into account the rigidity of the machined parts and the process of processing and other requirements, do not lose sight of the other.