Practice has proved that the choice of reasonable cutting amount is related to various factors such as machine tools, tools, workpieces and processes. The method of reasonable selection of processing amount is as follows:
(1) When rough machining, it is mainly necessary to ensure high production efficiency, so a larger amount of back eating knife, a larger feed, and a cutting speed U should be selected for medium and low speed.
(2) When finishing, the main requirements of the size and surface accuracy of the parts are guaranteed, so a smaller amount of back eating tools, a smaller feed, and a higher speed are selected for cutting speed.
(3) When rough machining, it is generally necessary to give full play to the potential of the machine tool and the cutting ability of the tool. When semi-finishing and finishing in CNC lathe factories, it should focus on how to ensure the quality of processing, and on this basis, maximize productivity. CNC lathe factory should ensure that the tool can process a part or ensure that the durability of the tool is not less than one work shift, and at least not less than half a work shift. The specific value of CNC lathe factory should be selected according to the provisions in the machine tool manual, tool durability and practical experience.
Selection of back-eating knife amount: The selection of back-eating knife amount is determined according to the stiffness of the machine tool, fixture and workpiece, etc., as well as the power of the machine tool. When the process system allows, select as large as possible back-eating volume. In addition to the allowance left for later operations, the remaining roughing allowance is cut off as soon as possible to minimize the number of passes.
Usually on medium power machine tools, the back-eating amount of roughing is 8~10 mm (unilateral). CNC lathe factory semi-finishing back eating volume is 0.5~5 mm; The amount of back eating knife during finishing is 0 2~1.5 mm.
Determination of feed volume: When the quality requirements of the workpiece can be guaranteed, a higher feed speed can be selected to improve productivity. When CNC lathe factory cuts, turns deep holes or fine turning, it is advisable to choose a lower feed speed. The feed speed should be adapted to the spindle speed and the amount of back knife eating. In rough machining, the choice of feed is limited by the cutting force.