Views:2 Author:Site Editor Publish Time: 2021-06-18 Origin:Site
I. Formulation of Processing Technology
1. Ensure the requirement of machining precision and surface roughness of parts with high efficiency;
2. Make the machining route as short as possible, which can not only reduce the program section, but also the tool free travel time.
3. Make the numerical calculation simple and the number of program segments small, so as to reduce the programming workload.
4. When determining the processing route of large CNC lathe, the processing allowance of workpiece, rigidity of lathe and cutter should also be considered to determine whether to carry out the machining once or several times.
5. One clamping, multi-direction machining and one forming should be carried out as far as possible.This can reduce the installation times of work pieces and shorten the time of handling and clamping. It can not only effectively improve the machining efficiency of large CNC lathe, but also ensure the position accuracy requirements of parts.
II. Tool Selection
1.Choose the right tool
In large-scale CNC lathe machining, the role of metal cutting tools is very important.The materials used to make cutting tools must have high hardness, wear resistance and heat resistance, sufficient strength and toughness, good heat conductivity and workmanship, and good economy.In the process of tool selection, on the premise of meeting the requirements of parts processing, the larger diameter tool should be selected as far as possible, which has better strength and toughness.In the same process, the number of tools selected is as small as possible to reduce the number of tool changes;Select as many general standard tools as possible without or without special non-standard tools.
2.Reasonable determination of tool setting point
（1）It is easy to use digital processing and simplify programming. It is easy to check when machining large CNC lathes and causes small machining errors.
（2）The position of the knife point can be selected on or outside the work piece (e.g. clamp or lathe), but it must be dimensionally related to the positioning datum of the part.
（3）The matching point should be selected as far as possible on the design or process basis of the part, for example, on the workpiece positioned by the hole, the center of the hole can be selected as the matching point.
III. Clamping and Installation of Workpieces
1. When the production batch of parts is small, modular fixture, adjustable fixture and universal fixture should be used as far as possible to shorten the production preparation time and save production costs.
2. Special fixture should be considered only in batch production, and strive for simple structure;
3. The loading and unloading of parts should be fast, convenient and reliable so as to shorten the downtime of the lathe.
4. The parts on the fixture shall not interfere with the lathe's machining of the surfaces of the parts.
5. Tool selection shall be beneficial to tool exchange and interference collision avoidance.
6. Multi-position and multi-part fixtures can also be used in batch production to improve processing efficiency.
IV. Selection of cutting parameters
Machining and cutting parameters of large CNC lathe include spindle speed, cutting depth and feed speed.When choosing cutting parameters for large-scale CNC lathe, if rough machining is used, productivity is generally increased. However, economy and processing cost should also be considered. Larger cutting depth and feed speed can be selected.If it is semi-finishing and finishing, efficiency, economy and processing cost should be considered on the premise of guaranteeing processing quality.The feed speed should be set as high as possible when the cutter moves through the empty range.The specific values shall be determined according to the lathe instructions, cutting quantity manual and experience.
V. Pre-adjustment of machining tools
Many different cutters are often used in the process of large-scale CNC lathes. If the cutters can not be pre-adjusted, it is necessary for the operator to install each cutter on the spindle and slowly determine their exact length and diameter.Then, input manually via the keys on the CNC control panel.If the tool alignment instrument is used, it can accurately measure the diameter and length of the tool, reduce the lathe occupancy time, improve the first pass rate and greatly improve the production efficiency of large CNC lathe.
The above five are the main factors affecting the machining efficiency of large-scale CNC lathes, but in the actual process of large-scale CNC lathes, the processing experience of operators of large-scale CNC lathes also affects the efficiency of large-scale CNC lathes to a certain extent. Only when all the factors affecting the processing efficiency of large-scale CNC lathes are fully considered and the processing technology of operators is improved,Only in this way can the production capacity of large CNC lathe be fully developed and the order quantity of machining be increased to a greater extent.